# Maha C-9000 vs. La Crosse BC-900



## FrontRanger (Jun 12, 2008)

I'm looking to buy a good AA charging/discharging/conditioning unit. After perusing Silverfox's excellent and detailed review here, it appears that the Maha C-9000 and the La Crosse BC-900 are about the best. To me, they appear to have similar features: four channels, independently variable charge/discharge rates, a nice display, "refresh" mode, temperature protection, etc. The C-9000 has a "break-in" mode for long-stored cells, and I'm not sure the BC-900 has that, but I'm not sure how useful that will be. The biggest difference I see is price: One can find the BC-900 for $36, but I found no better than $60 for theC-9000.

Can anyone offer additional insight between these two units? I know they have product revisions, so I'm interested in the latest version of each. Thank you.


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## SilverFox (Jun 13, 2008)

Hello FrontRanger,

In my opinion, once you understand the usefulness of the Break-In mode on the C9000, you will find that feature justifies the price of the charger. The fact that it does other functions is secondary as far as usefulness goes.

Tom


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## FrontRanger (Jun 13, 2008)

SilverFox said:


> Hello FrontRanger,
> 
> In my opinion, once you understand the usefulness of the Break-In mode on the C9000, you will find that feature justifies the price of the charger. The fact that it does other functions is secondary as far as usefulness goes.
> 
> Tom


 
Thanks, Tom. I don't mean to be dense, but why is the "Break In" feature so useful? I downloaded the user's manual for the C9000, and it states what procedure that mode performs, but it's not clear to me why that function is so useful. Or unique, for that matter - regarding the BC-900 in your review, you mention that "The refresh mode lets you *break in* new cells and revive old ones." What is the difference in functionality?

Thanks for your help.


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## Mr Happy (Jun 13, 2008)

It seems that the specific kind of long slow charge and discharge cycle that the "break-in" performs does something good to improve the operation of cells that it is applied to. Whether it redistributes the electrolyte evenly within the cell, or breaks down large crystal formations into smaller ones, or does something else, the results are beneficial. Internal resistance is often reduced, peak current capacity increased, voltage depression reduced, maximum capacity restored. Results may vary with the particular cell brand. For instance when applying a break-in cycle to a brand new and recently manufactured Eneloop it might be hard to measure the difference. For other brands, or older and more tired cells, the improvement can be significant.


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## TorchBoy (Jun 13, 2008)

FrontRanger said:


> To me, they appear to have similar features: four channels, ...


On its highest charge rate (which is lower than the MH-C9000's highest charge rate) the BC-900 has all of two channels. Similar, sure, but there are significant differences.


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## FrontRanger (Jun 13, 2008)

Mr Happy said:


> It seems that the specific kind of long slow charge and discharge cycle that the "break-in" performs does something good to improve the operation of cells that it is applied to. Whether it redistributes the electrolyte evenly within the cell, or breaks down large crystal formations into smaller ones, or does something else, the results are beneficial. Internal resistance is often reduced, peak current capacity increased, voltage depression reduced, maximum capacity restored. Results may vary with the particular cell brand. For instance when applying a break-in cycle to a brand new and recently manufactured Eneloop it might be hard to measure the difference. For other brands, or older and more tired cells, the improvement can be significant.


 
Thanks for the high-level description, Mr Happy. That does sound like a worthwhile feature. For further detail, I'd have to learn a lot more about battery chemistry, but I don't need to do that right now.


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## FrontRanger (Jun 13, 2008)

TorchBoy said:


> On its highest charge rate (which is lower than the MH-C9000's highest charge rate) the BC-900 has all of two channels. Similar, sure, but there are significant differences.


 
Thanks, I didn't know that. Now I see it in the user manual but it's not mentioned on La Crosse's web page for the BC-900.


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## Dogmeat (Jun 14, 2008)

Mind if I piggyback on this thread?

I'm looking for a charger too. I don't need it to sing and dance. I plan to basically rotate four rechargable AA's in a wireless mic pack I use on Sunday mornings. I'd like to pull two out of the charger on Sunday and put them in the unit. I'll put the two I just took out of the pack in the recharger and hope not to have to worry about them until the following Sunday.

To be honest that's about all this unit will be used for.

As I've read threads, it seems I need a charger what will charge the batteries, then shut off and then trickle charge to keep the power level up.

I don't want to sound like an idiot, but I don't want something I have to spend a lot of time learning to use or fussing with to get it to work right. I have plenty of complicated things in my life and my job, I don't need another.

I looked at the very basic charger that came with the Eneloops at Costco, I couldn't tell what it did or didn't do. Perhaps that's all I need, but having some way to tell what the charge was on an individual battery looks attractive.

The Maha C-9000 and La Crosse BC-900 look like nice units, but may be overkill for the limited use I'm planning. I don't want to spend more than I need to.

Any suggestions? Sorry for the long question, but I find giving as much info as I can upfront helps.


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## NA8 (Jun 14, 2008)

If lowest price is your main consideration, you might try the newer, cheaper LaCrosse BC-700. If you'd prefer the better engineered charger, there's no doubt the more expensive Maha C-9000 is lightyears ahead of the LaCrosse. This is kind of an old topic, so you'll get more information by just googling both models in this forum. There's been a lot written.


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## Dogmeat (Jun 14, 2008)

Oddly enough, it looks like the BC-700 is only a few dollars less than the BC-900...and more in some places. It looks like the 700 would do all I want, and more, but for $3-4 extra dollars I might buy the 900 instead.


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## TorchBoy (Jun 15, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



NA8 said:


> If lowest price is your main consideration, you might try the newer, cheaper LaCrosse BC-700.


What's the default charge rate on that? I vaguely recall that it's quite low.


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## NA8 (Jun 15, 2008)

The BC-700 battery charger has all the same features as the popular La Crosse BC-900, except the BC-700 is capable of charge rates of either 200, 500, or 700 mA. The BC 900 has charge rates of either 200, 500, 700, 1000, 1500, or 1800 mA (sort of  ). Other than the slower charge rates the BC-700 is identical in performance to the BC-900. The BC-700 is Black in color.

Black !!! Cool. 

http://thomasdistributing.com/shop/...ml?SP_id=74&osCsid=0dqk8eteveu40e9t1gf1dkp1b1


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## Niconical (Jun 15, 2008)

I've also been making the same choice recently, la Crosse Vs Maha. 

Both chargers seem great, with popular opinion coming down on the side of the Maha. That doesn't mean the La Crosse is bad though, in fact it seems to get stunning reviews wherever I look. 

The one thing that has swayed me towards getting the La Crosse BC900 is that the Maha C9000 and all of its multitude of settings and options, is from what I've read, very complicated to use. 

Look at this review on Amazon, scroll down a bit past the item and product details. 

http://www.amazon.com/dp/B000NLUSLM/?tag=cpf0b6-20

All those repeated key presses to do things on the Maha just puts me off.


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## TorchBoy (Jun 15, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*

NA8, I tried to find the answer to my own question but only found an implication. Is the default charge rate 200 mA?


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## NA8 (Jun 15, 2008)

Oh, I see. I've got the BC-900, just checked and it's 200mA default. I suspect the BC-700 is the same. No biggie though, you just hit the "Current" button and it toggles up. 

Assuming you know to change it 

Personally I think the Maha MH-C808M is the way to go. The C and D size low self discharge NiMH batteries in a Maglite with a P7 are just too sweet.


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## Black Rose (Jun 15, 2008)

NA8 said:


> Other than the slower charge rates the BC-700 is identical in performance to the BC-900. The BC-700 is Black in color.


So that means it too could have a meltdown?


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## Dogmeat (Jun 15, 2008)

This may be a question for another thread, but as far as the charging amps....

I've read that heat is a bad thing for batteries and that charging at a high amperage can damage the batteries. So, assuming you had the time to wait, is charging at the lower amperage better for battery life and preformance?

For me, if I have a whole week to let a AA sit on a charger, is 200mA better than a higher charge rate?


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## TorchBoy (Jun 15, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



Dogmeat said:


> For me, if I have a whole week to let a AA sit on a charger, is 200mA better than a higher charge rate?


I bet SilverFox will shortly mention something about vibrancy... 

But seriously, have you seen his fast charging/discharging test? That would be treating a NiMH about as harshly as is possible, but it still gave respectably good life. :twothumbs


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## Bones (Jun 15, 2008)

Black Rose said:


> So that means it too could have a meltdown?



Prior to purchasing my MH-C9000, I scoured the web for any reports that the BC-700 was prone to meltdowns, and never located any indication whatsoever that this was the case.

Should anyone else wish to do the same, its known to carry at least three brand names and four models numbers:

Voltcraft IPC-1L | Technoline BC700 | Technoline BL-700 | La Crosse BC-700

Except for a major identity crisis, it was my impression that its a very dependable charger.


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## Niconical (Jun 15, 2008)

Bones said:


> Prior to purchasing my MH-C9000, I scoured the web for any reports that the BC-700 was prone to meltdowns, and never located any indication whatsoever that this was the case.


 
*+1*

From my investigations, it seems the BC900 did have some heat issues in certain cirmumstances, but the BC700 has had no such problems.


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## Bones (Jun 15, 2008)

Dogmeat said:


> ...
> Any suggestions? Sorry for the long question, but I find giving as much info as I can upfront helps.



For a reasonable step up from the basic Eneloop charger that still retains plug 'n play simplicity and top quality, I would suggest the Sony BCG-34HRMF4:





Considering your anticipated usage, the 2700mAh Sony CycleEnergy cells bundled with the charger would likely serve you as well as the Eneloop, so this one purchase should be sufficient for your purpose.

It's currently selling for 28.68 at Amazon.com, which is not a bad deal considering it includes free delivery to your door and four of aforementioned Sony CycleEnergy cells.


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## Dogmeat (Jun 15, 2008)

The Sony BCG-34HRMF4 does look nice, especially with four good cells in the package.

Two questions I can't seem to find the answer for:

1. Does this unit trickle charge after the fast charge. If the cells will be charged in a few hours and I don't use them for a week, will not having a trickle to keep them at full strength become an issue?

2. There are some reports of the cells becoming hot during the charge. I don't care about a fast charge for the application I have in mind. I'm still wondering if a slow charge would be better over all.

Still, this is a very good suggestion. Thanks!!!


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## Bones (Jun 16, 2008)

Dogmeat said:


> ... 1. Does this unit trickle charge after the fast charge. If the cells will be charged in a few hours and I don't use them for a week, will not having a trickle to keep them at full strength become an issue?



There is no indication in the accompanying documentation that the Sony BCG-34HRMF4 applies a trickle charge Dogmeat, but that can not be construed as an absolute. Regardless, the prevailing wisdom is to avoid the extended trickle charging of NiMH cells.

Whether or not having the cells sit for a week or two after charging before being utilized is an issue though, is entirely dependent on the amount of capacity you require. However, even though the bundled 2700mAh cells are not low self-discharge, they should still retain more initial capacity than even freshly charged Eneloops for at least a few weeks after being charged.



Dogmeat said:


> ... 2. There are some reports of the cells becoming hot during the charge. I don't care about a fast charge for the application I have in mind. I'm still wondering if a slow charge would be better over all.



The BCG-34HRMF4 will charge one or two AA cells at 1050mAh, and three or four at 525mAh. Neither of these rates is considered even close to aggressive; but the former rate, especially, will cause the cells to get quite warm. I consider this a reasonable tradeoff for a quality plug n' play charger with a refresh function and fully independent charging channels and status displays.

Not that anyone will recommend leaving an active charger unattended for a week at a time, but going back to your original wish to simply swap out a set of cells every Sunday morning, the Eneloop model MQN05 is probably a good choice. It charges at a very benign 300mAh, and in a worse case charging scenario, should still time out well before there is any danger of anything going critical. It is even believed to apply what FlashCrazy aptly deemed a 'maintenance' charge, but again at a very benign rate that should minimize the negative effects of extended charging.

It used to be bundled with all the Eneloop power packs at Costco, but is now being phased out in favour of the less desirable model MQN06, which lacks the fully independent charging channels. Accordingly, you may have to do a little digging to find the MQN05, but it is also somewhat more commonly available in a bundle with 4 AA Eneloops.


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## Dogmeat (Jun 17, 2008)

>However, even though the bundled 2700mAh cells are not low self-discharge, they should still retain more initial capacity than even freshly charged Eneloops for at least a few weeks after being charged.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Thanks for the additional information. As I have read more reviews, it looks like the cells that come with the Sony charger tend to be garbage, so I'll need to buy some additional cells if I buy that unit...which, of course, makes it about the same price as the BC-900.

Choices are the blessing and the curse of our age.


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## Bones (Jun 17, 2008)

Dogmeat said:


> Thanks for the additional information. As I have read more reviews, it looks like the cells that come with the Sony charger tend to be garbage, so I'll need to buy some additional cells if I buy that unit...which, of course, makes it about the same price as the BC-900.
> 
> Choices are the blessing and the curse of our age.



Although the 2500mAh NiMH cells, especially the Energizer, are notorious for pre-mature failure, it has been my understanding that the 2700mAh cells currently available from Sanyo, Sony and Powerex in particular were far more reliable, albeit not in the same league as the Eneloop.

Accordingly, I would appreciate links to the reviews you are referencing. I feel badly for suggesting an inferior product.


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## ThatGuyBri (Jun 17, 2008)

The BC-900 is listed in the Good Deals forum.


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## Dogmeat (Jun 17, 2008)

Bones said:


> Although the 2500mAh NiMH cells, especially the Energizer, are notorious for pre-mature failure, it has been my understanding that the 2700mAh cells currently available from Sanyo, Sony and Powerex in particular were far more reliable, albeit not in the same league as the Eneloop.
> 
> Accordingly, I would appreciate links to the reviews you are referencing. I feel badly for suggesting an inferior product.


 
I was looking at the reviews on Amazon - 17 pages of them. Most of the reviews of the charger itself are highly positive. But there are lots of people who have had bad luck with the batteries. See: "*Great Charger, Batteries Are Garbage*, October 16, 2007"

I always take Amazon reviews with a grain of salt and it does look like most of the bad battery reviews are older.

Still, it does look like a great charger. "Don't apologize, it's a sign of weakness!"


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## Mr Happy (Jun 17, 2008)

There may be some truth to the Amazon reviews. I believe a few people here have posted about disappointment with the Sanyo 2700 mAh cells. The problem seems to be premature failure and rapid self-discharge, a bit like the infamous Energizer cells.


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## Bones (Jun 17, 2008)

Dogmeat said:


> I was looking at the reviews on Amazon - 17 pages of them. Most of the reviews of the charger itself are highly positive. But there are lots of people who have had bad luck with the batteries. See: "*Great Charger, Batteries Are Garbage*, October 16, 2007"
> 
> I always take Amazon reviews with a grain of salt and it does look like most of the bad battery reviews are older.
> 
> Still, it does look like a great charger. "Don't apologize, it's a sign of weakness!"



The bad reviews of the Sony 2700mAh cell really do get repetitive once you go back a bit on Amazon, which is too bad because it makes the BCG-34HRMF4 charger bundle a much less attractive purchase.

Until now, I've felt it was a very good choice for those just wanting to optimize the performance and longevity of their rechargables without having to immerse themselves in the attendant technology.

Perhaps Sony will start bundling the charger with their CycleEnergy Blue low self-discharge cells at some point in the future, and it will again be the viable option.

It also seems that the only high capacity NiMH cell that continues to perform acceptably is the Powerex offering.

C'est la vie ...


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## N162E (Jun 17, 2008)

Dogmeat said:


> For me, if I have a whole week to let a AA sit on a charger, is 200mA better than a higher charge rate?


Yes a lower charge rate is better. The 200ma rate of the BC 7 & 900 creates very little heat. Another feature of the LaCrosse is that it will reliably terminate at any of its rates the Maha will not reliably terminate below about 700 ma. The Maha default rate is 1000ma, fast and hot. If you want a lower rate with the Maha you have to program each slot individually. I have both chargers and use only LSD cells, Kodak, ROV and Eneloop.

When the LSD cells came out the rules seemed to really change. I can't understand why anyone would continue to use or heaven forbid at this time to purchase non LSD cells.


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## TorchBoy (Jun 17, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



N162E said:


> The Maha default rate is 1000ma, fast and hot.


Hot? Since when? It only gets hot if it misses termination, which happened a bit with the initial firmware but not with later revisions. That wasn't spoken (typed) from experience was it? :thumbsdow


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## Unforgiven (Jun 17, 2008)

N162E said:


> Yes a lower charge rate is better. The 200ma rate of the BC 7 & 900 creates very little heat. Another feature of the LaCrosse is that it will reliably terminate at any of its rates the Maha will not reliably terminate below about 700 ma. The Maha default rate is 1000ma, fast and hot. If you want a lower rate with the Maha you have to program each slot individually. I have both chargers and use only LSD cells, Kodak, ROV and Eneloop.
> 
> When the LSD cells came out the rules seemed to really change. I can't understand why anyone would continue to use or heaven forbid at this time to purchase non LSD cells.




My experience with the C9000 is not the same as yours. I have two of them and the only time good cells come close to being hot is while charging at 2 amps on all 4 bays at the same time. Charging at 1amp on either of those chargers, the cells will just be noticeably warm to the touch. I generally charge at .5C or so (about 500 mAh for AAA and 1 to 1.5 amp with AA cells) and only had a termination problem with some cells that came free with an electronic device I purchased. They were really junk cells. Rated at 1300 mAh and tested out between 500 and 700 mAh. (They didn't terminate charge on any of my other chargers either) I have charged good cells on the C9000 from 200 mAh to 2 amps (Eneloops, Powerex, Other Sanyo) and have not had a missed termination with any of those batteries. My chargers were made after the initial firmware change. 

The La Crosse BC-900 and BC-700 are both good chargers and are small in size compared to the C9000. (a definite plus) It was the break in mode on the C9000 that sold me on it.


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## FrontRanger (Jun 18, 2008)

TorchBoy said:


> Hot? Since when? It only gets hot if it misses termination, which happened a bit with the initial firmware but not with later revisions...


 


Unforgiven said:


> My experience with the C9000 is not the same as yours. I have two of them and the only time good cells come close to being hot is while charging at 2 amps on all 4 bays at the same time....


 
TorchBoy, Unforgiven: Thanks for the replies. The previous post disconcerted me, as I recently ordered the C9000. I assume the unit that's on its way to my house will have the latest firmware version, since I'm buying it new.


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## Black Rose (Jun 18, 2008)

Unless you've found a seller that has extremely old stock, you'll get one with the updated firmware.

I have a C9000 with the updated firmware, and it did miss termination on one cell. However that cell was in very bad condition and has since been recycled. 
With my Eneloops, Rayovac Hybrids and remaining regular NiMh cells, there have been no missed terminations.


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## N162E (Jun 18, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



TorchBoy said:


> Hot? Since when? It only gets hot if it misses termination, which happened a bit with the initial firmware but not with later revisions. That wasn't spoken (typed) from experience was it? :thumbsdow


Since always. Hot may be a stretch but I think 120 degrees is warmer than they need to get. This is from experience right now. 

Four Sanyo 2500s charged at 1000ma on the C-9000. They all terminated over about a 10 minute period telling me the Delta V was sensed. Both the Maha and the LaCrosse are incredible chargers. I personally don't care for the default rate of 1000ma of the Maha. Slower is cooler and better.

I use my LaCrosse's (Two of them) for charging. Maintenance operations I do on the Maha's (Two of them also).

With the LSD cells I am not finding the need to charge them up immediately before I use them. Less cycles less maintenance. Also, I have done some testing with new LSD cells, forming charges, cycling and other break in gyrations. Net result, almost no difference whether I use them right out of the pack, charge them first or cycle them. They all operate within a few percent no matter how I handle them.


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## N162E (Jun 18, 2008)

Black Rose said:


> Unless you've found a seller that has extremely old stock, you'll get one with the updated firmware.
> 
> I have a C9000 with the updated firmware, and it did miss termination on one cell. However that cell was in very bad condition and has since been recycled.
> With my Eneloops, Rayovac Hybrids and remaining regular NiMh cells, there have been no missed terminations.


Have you tried lower charge rates 200-500ma?


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## Black Rose (Jun 18, 2008)

N162E said:


> Have you tried lower charge rates 200-500ma?


Yes, but only in Break-In mode so far. I normally charge my AAs at 1000 ma.

I've got some cells that are a few years old that I don't really care about. I'll discharge them and toss 'em at 400ma and see what happens.


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## Bones (Jun 18, 2008)

N162E said:


> Thanks for pointing that out. Yes both of mine are the first release (0FAB01) I would be interested in hearing more on later releases. I would like the Maha C9000 a lot more if I could select a lower default charge rate and depend on accurate termination.
> 
> 
> 
> ...



As Mr Happy noted in a response to one of your prior posts, all but the first release of the MH-C9000 has a high-voltage override that certainly appears to have fully resolved its termination issues, at least with all but very sub-standard cells, and that in turn seems to have fully resolved the issue with cells over-heating.

Since your experience is with the first release, which is the only one known to me to have termination problems, I think it's important to make that distinction when posting a critique of the MH-C9000.

Admittedly, there may be other first releases in the supply chain, but the vast majority of current recipients will almost certainly receive a revised release, and I believe the resident experts on this Board have all concurred that it has a very reliable termination protocol.

Incidentally, I too have a first release and appreciate its ability to more completely charge healthy cells and, if desired, also charge C and D cells. But I also accept that the trade-off for holding on to this release is that I have to monitor it more carefully at minimul charging rates.


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## Black Rose (Jun 18, 2008)

Bones said:


> Incidentally, I too have a first release and appreciate its ability to more completely charge healthy cells and, if desired, also charge C and D cells. But I also accept that the trade-off for holding on to this release is that I have to monitor it more carefully at minimul charging rates.


How are you charging C and D cells with the C9000?


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## N162E (Jun 18, 2008)

Black Rose said:


> Yes, but only in Break-In mode so far. I normally charge my AAs at 1000 ma.
> 
> I've got some cells that are a few years old that I don't really care about. I'll discharge them and toss 'em at 400ma and see what happens.


I'll be interested in your results. I would be more interested in how it operates at lower ma rates with newer LSD cells which a lot of us are using now. Both of my LaCrosse's and C-9000s are early issue. 

I have a TNC light (Key Lux) that that uses a NIMH N cell with a AA adapter for charging. I think the N-cell has a capacity of about 450ma, the LaCrosse picks up the termination every time at the 200ma rate.


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## Dogmeat (Jun 18, 2008)

Thanks for all the information everyone. I think I'm going to go with the BC-900 over the Sony BCG-34HRMF4. It's probably more than I need, but it gives me a little more headroom if I decide I'd like to use more features in the future. Since the BC-700 sells for about the same price as the BC-900, I can't see why I'd buy it over the 900.

And if indeed the Sony batteries in the BCG-34HRMF4 are poor quality and I needed to buy new ones, the cost of the two units are about the same. And if I do buy any replacements, I will go with LSD cells (that will be the next post "What LSD cells to buy?).


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## Black Rose (Jun 18, 2008)

N162E said:


> I'll be interested in your results. I would be more interested in how it operates at lower ma rates with newer LSD cells which a lot of us are using now. Both of my LaCrosse's and C-9000s are early issue.


All 4 cells have terminated properly at a 400 ma charge rate. 
The first cell terminated in 310 minutes, the other 3 terminated in 370 minutes.

These cells are about 2 1/2 years old. The first cell showed a 16% capacity loss when I did the break-in cycle on it previously, and is the worst cell I currently own. It's one of my beater cells and will be destined for the recycle bin by the end of the summer.

All of my LSD cells are currently charged up folllowing break-in cycles. It will be about a month or so before I have some LSD cells in need of being recharged.


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## kitelights (Jun 18, 2008)

For your use, I'd recommend (as someone else did) that you try to find a Costco Pack with the older individual channel charger. 

Even if you paid full retail ($30-35) and shipping, you're getting a good deal for your application. 

You'll have a slow smart charger, 8 AA cells and 4 AAA cells and they're Eneloops. You won't have to charge once a week unless you want to. They hold their charge so well that you won't have to top off before use.


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## Dogmeat (Jun 18, 2008)

One of the advantages of living in Washington is that we often get the new items at Costco before everyone else does...but that means we're the first to have old stock vanish.

I find the store in Issaquah where I often shop - right across from the corporate HQ - has this effect even more than the other stores. I will look, but I'm not sure how to tell one charger from the other.



kitelights said:


> For your use, I'd recommend (as someone else did) that you try to find a Costco Pack with the older individual channel charger.
> 
> Even if you paid full retail ($30-35) and shipping, you're getting a good deal for your application.
> 
> You'll have a slow smart charger, 8 AA cells and 4 AAA cells and they're Eneloops. You won't have to charge once a week unless you want to. They hold their charge so well that you won't have to top off before use.


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## Bones (Jun 18, 2008)

Dogmeat said:


> ...
> Since the BC-700 sells for about the same price as the BC-900, I can't see why I'd buy it over the 900.



I suppose it depends on how confident you are that Murphy's law doesn't apply to you. As noted in a prior post in this thread, while there have been no reports of the BC-700 melting down, that is not the case with the BC-900.

Although almost all of these reports concerned version 32 of the BC-900, there have also been scattered reports of the same problem occurring in version 33, which is the current release.

This post, for example, reports the meltdown of one version 32 and two version 33 BC-900 chargers. It states that in all cases, "*one or more of the compartment keys melted into the charger and became inoperable*".

There is also this post on Amazon reporting a meltdown of a version 33, and this post of another meltdown which lacks a version number, but concerns a recent enough purchase to reasonably be a version 33.

Anyway, the reported meltdowns of the current version, although very rare, have nonetheless prompted some informed users to suggest sensible precautions such as never using the BC-900 in close poximity to flammables or on a flammable service.


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## NA8 (Jun 19, 2008)

These La Crosse threads are always great. I wouldn't buy a BC-900 thinking you're getting something extra for the extra bucks. Their design wimps out the higher you go in charge current. Both the BC-900 and the BC-700 are only really good at 200, 500, and 700ma. After that you better have a fan on it. I'd save the extra money and pick up the cool black model. Assuming of course you really don't think the 808M would come in handy down the road.


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## N162E (Jun 19, 2008)

NA8 said:


> These La Crosse threads are always great.


Yes they are. Soon after this one fades out there will be another.


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## lowatts (Jun 20, 2008)

Bones said:


> Anyway, the reported meltdowns of the current version, although very rare, have nonetheless prompted some informed users to suggest sensible precautions such as never using the BC-900 in close poximity to flammables or on a flammable service.


That's a good precaution with any charger :thumbsup:


----------



## FredM (Jun 20, 2008)

NA8 said:


> These La Crosse threads are always great. I wouldn't buy a BC-900 thinking you're getting something extra for the extra bucks. Their design wimps out the higher you go in charge current. Both the BC-900 and the BC-700 are only really good at 200, 500, and 700ma. After that you better have a fan on it. I'd save the extra money and pick up the cool black model. Assuming of course you really don't think the 808M would come in handy down the road.



That is really odd that it cannot handle higher than .7A.

I have a 12 dollar Duracell charger that does 2A without breaking a sweat. That is less than 1.5 amps at 12V. Not a large load


----------



## N162E (Jun 20, 2008)

FredM said:


> That is really odd that it cannot handle higher than .7A.
> 
> I have a 12 dollar Duracell charger that does 2A without breaking a sweat. That is less than 1.5 amps at 12V. Not a large load


Check your facts before you post Fred. The Lacrosse BC-900 can charge all four slots up to 1000ma and charge 2 slots up to 1800ma. In addition its about half the size of the Maha. Which one of these two chargers are you using?


----------



## Bones (Jun 20, 2008)

Bones said:


> ...
> Anyway, the reported meltdowns of the current version, although very rare, have nonetheless prompted some informed users to suggest sensible precautions such as never using the BC-900 in close poximity to flammables or on a flammable service.
> 
> 
> ...



+1 ...


----------



## lengendcpf (Jun 21, 2008)

*Maha C-9000 or the La Crosse BC-900?*

Deciding between these 2 chargers for charging AA/AAA Nimh/Nicd batteries. Please help me to choose. Thanks.


----------



## NA8 (Jun 21, 2008)

N162E said:


> Both of my LaCrosse's and C-9000s are early issue.



Sounds like you got your BC-900s before they had a chance to find cheaper vendors for the components.


----------



## KuoH (Jun 21, 2008)

I've only had my BC-900's for a couple of weeks and I'm quite happy with them. I like the Maha's backlit display and higher charging current options, but I much prefer the simultaneous channel displays of the LaCrosse over the Maha's. I don't see any 33's when the BC-900 powers up, but slot #4 does show a 35 briefly, which I assume means v35? So far, most of my charging has been at 200mA on old Digital brand 1800 and 2000 NiMH's and I haven't seen any temperature or termination issues. I'm now starting to charge them at 500mA and 1000mA to see how well these cheap batteries will hold up, and they're looking good so far.

If Maha were to come out with a new model with simultaneous displays and completely resolve the termination issues, or at least do it as well as most other chargers, then I'd consider getting one. For now, the BC-900's will do and if I need 4 more channels, I'll probably end up with another BC-900.

KuoH


----------



## TorchBoy (Jun 21, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



N162E said:


> Both of my LaCrosse's and *C-9000*s are early issue.





N162E said:


> Check your facts before you post Fred.


Perhaps you could similarly check your model numbers before you post?  There's no need to be quite so harsh.

:laughing:


----------



## KuoH (Jun 21, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*

I believe he means both his LaCross BC-900 and Maha C-9000 chargers are early issues, not a LaCross C-9000.

KuoH



TorchBoy said:


> Perhaps you could similarly check your model numbers before you post?


----------



## NA8 (Jun 21, 2008)

Talk about no respect, the BC-700 doesn't even rate getting into the poll.


----------



## lengendcpf (Jun 21, 2008)

NA8 said:


> Talk about no respect, the BC-700 doesn't even rate getting into the poll.


 
Sorry bro. The poll was set up by me actually.

After readings this thread here, I am torn between the C-9000 and the BC-900 only.

But somehow or rather, the mods merge my poll into this thread..


----------



## lengendcpf (Jun 21, 2008)

By the way, the bad about the La Crosse is that, components tend to burn out during high current charging while the Maha doesn't terminate properly?

But the problems encountered above, are using what version of the firmware? Maybe the newest don't have any problems?

So anyone who have just bought(bought in may or jun 08) any of the 2 chargers can confirm whether the problem still exists?


----------



## TorchBoy (Jun 22, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



lengendcpf said:


> But somehow or rather, the mods merge my poll into this thread..


So _that's_ where it came from.


----------



## SilverFox (Jun 22, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*

Hello Legend,

I think the down side of the BC-900 is that the buttons don't have a good feel to them, it doesn't have a Break-In function, it has a higher rate of failure, and sometimes when it fails it melts the charger and cells down. It is also incapable of being used from a 12 volt power source.

The charge termination issues were only associated with the C9000 chargers that start with 0F in their model number. Even those early chargers would terminate properly as long as you selected a charging rate in the 0.5 - 1.0C range. The missed terminations were usually observed when trying to charge at low charge rates.

The down side to the current C9000 chargers is its size, that the display and function is separate for each cell and you have to enter the setting for each cell individually (no global entry), the charger and cells heat up when charging 4 cells at 2 amps, and the default 1000 mA charge rate is over 1C for most AAA cells.

Tom


----------



## Bones (Jun 22, 2008)

lengendcpf said:


> By the way, the bad about the La Crosse is that, components tend to burn out during high current charging while the Maha doesn't terminate properly?
> 
> But the problems encountered above, are using what version of the firmware? Maybe the newest don't have any problems?
> 
> So anyone who have just bought(bought in may or jun 08) any of the 2 chargers can confirm whether the problem still exists?



In an attempt to achieve the highest possible state of charge, the first version of the MH-C9000 used a charging algorithm that proved too aggressive. It caused repeated charge termination failures, especially in less healthy cells.

Within a couple of months of the charger's release in the latter part of 2006, MahaEnergy addressed these termination failures by updating its firmware. They continue to advise this was the only firmware update the charger received.

Mr Happy recently summarized the update and its effect thusly:



Mr Happy said:


> Yes, the later releases of the C9000 have a high voltage override that terminates charging when the cell voltage reaches 1.47 V. All high quality cells I have tested exceed 1.47 V on charging (e.g. Eneloops max out at 1.51 V or more), so charging will be certain to terminate on cells like these at any charging current. You can charge Eneloops at 200 mA for instance.
> 
> When the charger finishes the normal charging phase it switches to a 100 mA top off charge for a further 2 hours. This helps to make up for the slightly incomplete charge produced by the high voltage termination.
> 
> Many believe the slightly lower completeness of charge is a reasonable compromise for the benefit of certainty of termination and the very cool charging temperatures at any charging rate.



In assessing the MH-C9000, it is important to determine whether the critiques you are reviewing concern an original or updated version.

In this thread, for example, the critique by N162E in post 30 concerns an original version. Although not mentioned in the post, N162E established this in a prior thread in post 15.

Conversely, the critique by Unforgiven in post 32 concerns an updated version of the MH-C9000. You will note this is clearly established in the post.

Accordingly, I think it's reasonable to conclude that the post by Unforgiven is applicable to your assessment, whereas the post by N162E is not since it only speaks to issues that were resolved by the firmware update.

I also think it's reasonable to conclude that the charge termination failures, which in turn caused cells to overheat, were in fact resolved by the firmware update the charger received early in 2007.

The current version of the MH-C9000 may have its less desirable traits, but I don't believe that charge termination failures and overheated cells are still amongst them.


----------



## Nisei (Jun 22, 2008)

So the advice from Maha not to charge at a lower rate than 0.3C can be ignored for all chargers with the latest firmware? Or does that have to do with something else?


----------



## KuoH (Jun 22, 2008)

So does that mean the newer firmware will terminate as reliably at 200mA and 500mA as a BC-900 and other chargers out there? I know Maha recommends at least .3C, preferrably .5C, for reliable detection, but most of the time I'm just not in that much of a hurry and I don't like the thought of heating up my batteries much beyond room temperature unnecessarily. I know this is more of a personal preference rather than a functional necessity, but if the other chargers can do it, or at least give the impression that they do, then why can't the C-9000? I also have read the suggestions of putting it on a wall timer or tossing marginal batteries, which aside from less capacity and the heat issues at high charging currents, are still perfectly usable. But, why is that even necessary when we're paying almost double for the C-9000 over its next competitor, which can do it correctly and perform nearly 95% of the same functions? Still, if Maha were to update their display to be more informative, I probably would get one as well for the rare occasions that I need a charger in the car or to be able to charge at 1C.

KuoH



Bones said:


> The current version of the MH-C9000 may have its less desirable traits, but I don't believe that charge termination failures and overheated cells are still amongst them.


----------



## SilverFox (Jun 22, 2008)

Hello KuoH,

Keep in mind that reliable termination and slow charge rates don't usually go hand in hand.

Most chargers use the fact that there is a drop in voltage when the cell is fully charged to terminate the charge. Unfortunately, this drop in voltage signal is only reliable when the cell is fully charged in about 1 hour. It is somewhat reliable when the cell is charged in about 2 hours, but when the charge rate drops below that it is not reliable.

This means that chargers that offer low charging rates must have secondary termination methods.

One of the methods of secondary termination is to stop the charge when the cell reaches a specific voltage. The BC-900 terminates the charge when the cell voltage reaches around 1.5 - 1.51 volts. The C9000 terminates when the cell voltage reaches 1.47 volts. 

The C9000 actually is able to put more of a charge into cells even though it terminates the charge earlier than the BC-900 does. It does this because at the end of the main charge, it applies a 100 mA top off charge for 2 hours.

Another method of secondary termination is on time, or on total amount of charge put into the cell. If you have crap cells that don't easily reach a peak voltage, the BC-900 will "time out" before the C9000 will.

I might also point out that even though you charge a cell at a low rate and it doesn't heat up, that doesn't mean that overcharging damage is not occuring to your cells.

The most reliable slow charge is to completely discharge the cell before charging, then charge on a timed charger at 0.1C for 16 hours. Unfortunately, this method uses up a lot of cycle life, and you end up needing a separate charger for each different capacity cell. 

All in all it is best to charge in the range of 0.5 - 1.0C and rely on the chargers main termination method. This leaves you a couple of back up termination methods in the even that the charge termination signal is missed.

Tom


----------



## KuoH (Jun 22, 2008)

While that all sounds logical, I'm forced to wonder if the primary termination method was failing, then why was the BC-900 was still terminating more reliably when the C9000 has a lower peak voltage threshold? Or was that just changed with the newer firmware versions? Also, I have yet to see mine, or many reports of other BC-900's pumping in much more than the rated capacities into a good cell, so it's definitely not hitting the 3000mAh limit. Granted, my inventory of batteries is rather small and limited in type compared to some of you, but I imagine this may also be the case with a number of the other less vocal owners of either of these two chargers.

As for the mandatory top off charge the C-9000 forces into the battery, whether charging correctly terminated or not, I can't say I'm all that fond of that particular feature. This, along with the extra high capacity and peak cell voltage limit, would seem to be something Maha could easily implement as user selectable options in the firmware without much additional development cost. The display information still leaves something to be desired, but could be overlooked if all else were in order. Given the fact that the BC-900 seems to terminate more reliably and has a lower time limit for backup termination and is cheaper, I'm still of the opinion that it is the better, or at least less worrisome, charger of the two for AA and AAA use. Especially with the newer high cap AA's being just shy of the 3000mAh limit. I may have to change my tune, if and when I graduate to the big leagues and need a good C and D capable charger.

KuoH



SilverFox said:


> This means that chargers that offer low charging rates must have secondary termination methods.
> 
> One of the methods of secondary termination is to stop the charge when the cell reaches a specific voltage. The BC-900 terminates the charge when the cell voltage reaches around 1.5 - 1.51 volts. The C9000 terminates when the cell voltage reaches 1.47 volts.


----------



## Black Rose (Jun 22, 2008)

KuoH said:


> So does that mean the newer firmware will terminate as reliably at 200mA and 500mA as a BC-900 and other chargers out there?


I did a test last week where I charged four 2000 mAh Rayovac non-LSD AA cells at 500 mA. All four cells properly terminated.

I have a C9000 with firmware 0G0KA, purchased in March of this year.


----------



## KuoH (Jun 22, 2008)

I take it then that you normally charge at much higher currents? If so, then I don't think one charge a week is sufficient a data point to make a proper determination of any change.

KuoH



Black Rose said:


> I did a test last week where I charged four 2000 mAh Rayovac non-LSD AA cells at 500 mA.


----------



## Black Rose (Jun 22, 2008)

KuoH said:


> I take it then that you normally charge at much higher currents? If so, then I don't think one charge a week is sufficient a data point to make a proper determination of any change.


I normally charge at 0.5C on the C9000 and 1.0A on my C800S.

Those test cells were older cells (2 1/2 years old) that have only been charged on the C9000 twice. 

Before that they were regularly charged on a Rayovac PS16 charger @ about 220 mA, so these cells have a long history (2+ years) of being charged at lower currents.


----------



## KuoH (Jun 22, 2008)

I see, so you would've normally charged these cells at 1A then? Thanks for the background information on your cells, but I feel compelled to point out that it wasn't the age or condition of the cells which were in question. The question was whether the new firmware of the C-9000 allowed it to correctly, or at least non-detrimentally, charge most cells at less than .5C on a regular basis. So far, it seems the C-9000 owners just stick with .5C or above and toss out any cells which do not conform. Although it's not a terribly costly thing to do given the price of today's cells, it's still not something I would relish doing regularly.

KuoH




Black Rose said:


> I normally charge at 0.5C on the C9000 and 1.0A on my C800S.
> 
> Those test cells were older cells (2 1/2 years old) that have only been charged on the C9000 twice.


----------



## FrontRanger (Jun 22, 2008)

Black Rose said:


> I have a C9000 with firmware 0G0KA, purchased in March of this year.


 
Hi Black Rose, where did you find out that this number corresponds to the firmware version? Thanks.

Mine also says 0G0KA and was bought last week.


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## KuoH (Jun 22, 2008)

It's mentioned in the C-9000 support/faq thread, and probably some of the other C-9000 specific threads as well.

KuoH



FrontRanger said:


> Hi Black Rose, where did you find out that this number corresponds to the firmware version?


----------



## SilverFox (Jun 22, 2008)

Hello KuoH,

If you put cells in the C9000 and select 200 mA as the charging rate, they will terminate and not harm the cells.

If you put cells in the C9000 and select 300 mA as the charging rate, they will terminate and not harm the cells.

If you put cells in the C9000 and select 400 mA as the charging rate, they will terminate and not harm the cells.

The same goes for the 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, and 2000 mA rates.

Does that clear things up?

I have run hundreds of cells through both the C9000 and the BC-900. I see fewer missed terminations on the C9000 than I do on the BC-900, and I don't keep crap cells.

Tom


----------



## KuoH (Jun 22, 2008)

Not really, but I see that you seem to have lost the desire to discuss the particular technical questions I brought up, favoring instead a generic it just works response. Admittedly, you have more experience with both chargers, but I can't seem to find any new information to indicate the low charging rate issues have been adequately addressed, other than a change in the charging recommendations to avoid the problem scenarios and to throw away what might otherwise be useable cells with other chargers. While that can be a viable option for some, it's just not one that I'd like to pursue.

KuoH



SilverFox said:


> Does that clear things up?
> 
> I have run hundreds of cells through both the C9000 and the BC-900. I see fewer missed terminations on the C9000 than I do on the BC-900, and I don't keep crap cells.


----------



## NA8 (Jun 22, 2008)

KuoH said:


> Not really... I can't seem to find any new information to indicate the low charging rate issues have been adequately addressed, other than a change in the charging recommendations to avoid the problem scenarios and to throw away what might otherwise be useable cells with other chargers. While that can be a viable option for some, it's just not one that I'd like to pursue.
> 
> KuoH



Reading through the thread, I think your questions have been answered, but they aren't satisfying you for some reason. It sounds as though the Maha's software upgrade fixed the low rate issues, it doesn't overheat batteries, and it terminates well. I take it you seem to feel it doesn't perform perfectly with "marginal" batteries that you want to squeeze more life out of. I think that's an issue for reasonable consideration, but not something to base a final recommendation on all other things considered. However, if your LaCrosse is still working well, good for you. I'd love to see a Maha with a LaCrosse style display also. I've found the operation of the 808M to be a nice compromise. It shows a simple display of all the batteries at once. No voltage or current readings, but no tedious setup either. C&D battery capability just an added bonus.


----------



## Black Rose (Jun 22, 2008)

KuoH said:


> So far, it seems the C-9000 owners just stick with .5C or above and toss out any cells which do not conform. Although it's not a terribly costly thing to do given the price of today's cells, it's still not something I would relish doing regularly.


As for the 0.5C, that's the minimum rate as recommended by industry experts; it's not something tossed out by folks here and everyone else follows like lemmings.

See the "Charging nickel-metal-hydride" section for more information.
Also see "How to charge - when to charge table".

I don't know about others, but of the 110 NiMh rechargeables I have, I have had to only recycle 8 of those since getting the C9000 and was finally able to determine what their capacities were. 

For the record, if it wasn't for the reports here and other places on the net of the current version of the BC-900 still having meltdowns, I'd have one of those as well. 
Should Lacrosse ever resolve that issue, then I'll get one.


----------



## Black Rose (Jun 22, 2008)

FrontRanger said:


> Hi Black Rose, where did you find out that this number corresponds to the firmware version? Thanks.
> 
> Mine also says 0G0KA and was bought last week.


Here is a thread that notes the firmware numbers.

Units with serial numbers starting with 0F had issues.
Unit with serial numbers starting with 0G have the revised firmware.


----------



## KuoH (Jun 22, 2008)

I see where a couple of individuals mentioned that they tested the low charge rate termination once, but didn't follow-up with any repeated or long term results at the lower levels. The C-9000 users pretty much all unequivocally state that they mostly just use the high charging rates, thus my continued quandary as to whether Maha improved detection to a point where it is at least as reliable as other chargers at the low rates. So no, I guess I'm not yet sufficiently satisfied that Maha has fix this particular problem.

Silverfox explained that peak voltage detection is probably what both chargers are using to signal termination, since -dV is difficult to detect at the low rates, and that the C-9000 has a lower limit than the BC-900. I'm now watching my chargers more closely to verify if that's the case. If most of my 200mAh charges terminate before 1.5V and the batteries aren't hot, then I guess I can assume the primary termination method was successful. My question concerning the C-9000 at this point is whether its peak voltage has always been 1.47V from the beginning or new with the current firmware?

KuoH



NA8 said:


> Reading through the thread, I think your questions have been answered, but they aren't satisfying you for some reason. It sounds as though the Maha's software upgrade fixed the low rate issues, it doesn't overheat batteries, and it terminates well.


----------



## TorchBoy (Jun 22, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



Black Rose said:


> Unit with serial numbers starting with 0G have the revised firmware.


And (I think) from 0G0IA onward there was the revised revised firmware, with the repeating digits problem fixed.


----------



## Bones (Jun 22, 2008)

KuoH said:


> While that all sounds logical, I'm forced to wonder if the primary termination method was failing, then why was the BC-900 was still terminating more reliably when the C9000 has a lower peak voltage threshold? Or was that just changed with the newer firmware versions?
> ...



It was implemented in the revision, as noted in Mr Happy's summary in post 62, and there was actually only one revision, as noted in the same post.

Now, if you accept that charging at slower rates significantly increases the likelihood that the charger will have to rely on voltage to terminate its charge, it seems self-evident that the odds favour the voltage setting chosen for the MH-C9000.

As noted by SilverFox in post 65, the MH-C9000 terminates its charge at 1.47 volts, and then reverts to a top-off charge, whereas the BC-900 terminates its charge between 1.50 and 1.51 volts without reverting to a top-off charge.

In his summary in post 62, Mr Happy noted that the Eneloop, for example, can also reach its peak voltage at 1.51 volts. It therefore appears inevitable that situations will arise where even high quality cells will reach their peak voltage before the BC-900 terminates its charge at slower rates.

The higher voltage setting utilized by the BC-900 also come into play with the marginal cells you alleged are just tossed by owners of the MH-C9000 in post 70. Marginal cells will reach their peak voltage even sooner than healthy cells, so once again the setting utilized by the BC-900 increases the likelihood that it will fail to terminate as reliably with these cells as the MH-C9000.

Incidentally, the only new fact set down in this post is that marginal cells reach their peak voltage sooner than healthy cells. Everything else was contained in Mr Happy's summary in post 62 or SilverFox's statements in post 65, so may wish to afford both a closer review and then reconsider your statements in post 74.

Termination issue aside, if you want to assess the respective merits of the MH-C9000 and BC-900, you might want to start by becoming familiar with their respective manuals, which will provide a reasonable insight into their similarities and differences; and there truly are significant differences.

Since you already have a BC-900 and, I presume, its manual, you can download the manual for the MH-C9000 here.


----------



## KuoH (Jun 22, 2008)

Yes I had seen that document, but as far as I can tell, the .5C recommendation was more to facilitate more reliable full charge detection rather than just being better for the cell overall. It does also state that "lingering slow charges cause [FONT=Verdana, Arial, Helvetica, sans-serif]crystalline formation", which I think refers to leaving on the charger well after a full charge. It also makes mention of the 8-16mV voltage drop detection being the typical signal fast chargers use to detect a full charge. As I recall from some of the other threads, these chargers are capable of detecting voltage drops smaller than that, though their true accuracy remains to be seen. In fact, as I type this response, I just watched one of my cells go from charge to discharge at somewhere just over 1.4V and it is barely warm, so the BC-900 must have detected something other than peak voltage to trigger termination. Granted, I'm probably not going to use this cell for anything more than powering up a flashlight to give to the kids to play with, but I'm not about to throw it away if it can still run something of use.

As for the meltdown issue, I did see those messages as well as the pictures, but I didn't find the frequency of those occurrances in the new versions to be alarming enough to put me off purchasing them. Hopefully the v35's I got will be immune, but I'm observing some of the cooling recommendations others have mentioned. Worst case, I make a phone call to La Crosse warranty department and perhaps start looking around for another capable charger.

KuoH
[/FONT]


Black Rose said:


> As for the 0.5C, that's the minimum rate as recommended by industry experts; it's not something tossed out by folks here and everyone else follows like lemmings....
> For the record, if it wasn't for the reports here and other places on the net of the current version of the BC-900 still having meltdowns, I'd have one of those as well.
> Should Lacrosse ever resolve that issue, then I'll get one.


----------



## Bones (Jun 22, 2008)

It bears mentioning that insofar as I'm concerned, predicating the decision on which of these chargers to purchase based primarily on its ability to terminate a charge is ill advised.

Both chargers have a proven ability to terminate reliably in reasonable circumstances, but then so does the MQN05 and a bunch of other Sanyo chargers bundled as throwaways with the Eneloop.

I chose the MH-C9000 because I believe it better enables me to maximize the performance and longevity of my cells, and in this regard I am satisfied it is without peer at anywhere near its price range.


----------



## KuoH (Jun 22, 2008)

Actually, I'm not sure I accept that slower rates will significantly increase the likelihood that the charger will have to rely on peak voltage termination, especially considering I just observed my BC-900 terminate charging on a less than ideal cell at just over 1.4V, probably 1.43-1.44V given the time between observations. It takes quite awhile for a 0.01V rise at 200mAh, and my previous observation was at 1.43V only 10 to 15 minutes prior to noticing it had begun to discharge. I suppose I may just have to setup a video camera to log more such events.

I agree with your statement that the lower termination voltage of the C-9000 would seem to position it better to reliably end a charge on a questionalbe cell that has missed primary termination. Which is why I asked the question of when it was implemented to help me better understand all the reports of severe overcharging. I did overlook your quote of Mr Happy where he mentioned the feature being added, though I must point out that I can't find the message anywhere in the thread. I guess it was cross posted from a different thread, and I must have skipped over it presuming it was something I had already read in this thread. Never the less, the fault is mine for overlooking that.

Still, wasn't there at least one report of someone pumping nearly 10Ah into an AA and still not hitting -dV or peak voltage termination? For a charger that is physically designed to primarily use AA and AAA batteries, that would seem to be a bad characteristic to have in conjunction with the termination issues. With the BC-900, I may be concerned if it tried to put 3Ah into a cell, but certainly not as much concern as 10Ah would cause. I may regret the decision if and when 3+Ah cells become the norm, but I'll probably be looking for another charger by then anyway.

So it is accepted that the C-9000 most likely has to resort to peak voltage termination at low charging rates, am I correct? As for the BC-900, at least the 2 v35 units I have, that has not been my recollection of events and is not what I'm observing so far as a normal occurrance, but I'll continue to monitor it closely.

KuoH



Bones said:


> Now, if you accept that charging at slower rates significantly increases the likelihood that the charger will have to rely on voltage to terminate its charge, it seems self-evident that the odds favour the voltage setting chosen for the MH-C9000.
> 
> As noted by SilverFox in post 65, the MH-C9000 terminates its charge at 1.47 volts, and then reverts to a top-off charge, whereas the BC-900 terminates its charge between 1.50 and 1.51 volts without reverting to a top-off charge.
> 
> In his summary in post 62, Mr Happy noted that the Eneloop, for example, can also reach its peak voltage at 1.51 volts. It therefore appears inevitable that situations will arise where even high quality cells will reach their peak voltage before the BC-900 terminates its charge at slower rates...


----------



## KuoH (Jun 22, 2008)

I agree, making a decision on which charger to purchase based primarily on it's termination abilities is not a wise move. It does however, still have some impact on the overall decision making process for the user. For myself, it was the combination of the price, display as well it's reasonably good analyzation features, which helped me to decide on the second BC-900 over the C-9000. Though I must admit that I'm jealous of the backlight on the C-9000. I may possibly lose some 10 to 20 percent of the cell's usable cycles, compared to what the C-9000's break-in feature might add, but I figure I can gain some of that back at the back end by not prematurely recycling what I would still consider usable cells if treated gently.

KuoH



Bones said:


> It bears mentioning that insofar as I'm concerned, predicating the decision on which of these chargers to purchase based primarily on its ability to terminate a charge is ill advised.


----------



## Bones (Jun 22, 2008)

KuoH said:


> ...
> So it is accepted that the C-9000 most likely has to resort to peak voltage termination at low charging rates, am I correct? As for the BC-900, at least the 2 v35 units I have, that has not been my recollection of events and is not what I'm observing so far as a normal occurrance, but I'll continue to monitor it closely.



You may very well be correct that the MH-C9000 resorts to peak voltage detection at low charge rates, but not necessarily because it must. I think the MahaEnergy engineers decided that relying on any other methodology at charge rates less than 1C was a fool's game.

I believe that all NiMH chargers rely on essentially the same techniques to terminate a charge, and I think the team who designed the MH-C9000 could have duplicated the one used by the BC-900 in a heartbeat. In fact, the only real advantage I would afford in this regard is to the developer of the cell being charged. For example, I don't think there is anyone who understands the characteristics of the Eneloop anywhere near as well as the engineers at Sanyo.

Everything I have read about the end of charge characteristics of the NiMH cell has validated SilverFox's statement that they do not produce a reliable end of charge signal at rates less than 1C. In fact, I would go even further and state that as a cell ages, even that becomes nebulous.

It therefore seems to be a basic tenant of charging NiMH cells that termination techniques that rely on anything other then peak voltage detection, especially at slower charge rates, are doomed to repeated failures at some point in a cells life.

Anyway, I have come to believe the MahaEnergy engineers chose the best overall compromise having regard everything I currently know about this topic.

On a related note, I wanted to mention the ThomasDistributing site still states that version 33 is the lastest update to the BC-900, so I wouldn't presume that your chargers are version 35 or immune to meltdowns until you confirm otherwise. The statement is under the descripton tab for the BC-900.


----------



## Black Rose (Jun 23, 2008)

KuoH said:


> [FONT=Verdana, Arial, Helvetica, sans-serif]Hopefully the v35's I got will be immune, but I'm observing some of the cooling recommendations others have mentioned. Worst case, I make a phone call to La Crosse warranty department and perhaps start looking around for another capable charger.[/FONT]


V35?

Where did you get them from? Thomas Distributing (seems to be the favoured source for the BC-900) still shows V33 as the latest version.


----------



## KuoH (Jun 23, 2008)

It also states that the unit ships with 2400mAh and 800mAh cells while I got 2600mAh and 1000mAh cells, at least that's what the labels say as well as the manual listing the corresponding charging times for the new capacities. It doesn't surprise me that the sales information on websites aren't always up to date, but the power on screen does indeed state 35 in slot 4, which in my research seems to indicate v35. The first two slots also seem to display numbers very close to ambient temps in F, while the old versions were in C I thought? Whether there are any other noticeable changes between v35 and v33 remains to be determined. Besides, wasn't there also some disconnect between TD's description of the C-9000's charge detection capabilities and Maha's website initially? I seem to recall the debate caused quite a run in one of the threads.

KuoH



Bones said:


> On a related note, I wanted to mention the ThomasDistributing site still states that version 33 is the lastest update to the BC-900, so I wouldn't presume that your chargers are version 35 or immune to meltdowns until you confirm otherwise. The statement is under the descripton tab for the BC-900.


----------



## Black Rose (Jun 23, 2008)

One of the problems I've noticed with Thomas Distributing is that they have multiple web sites. 

Depending on which one you go to, you get different information.


----------



## Bones (Jun 23, 2008)

KuoH said:


> It also states that the unit ships with 2400mAh and 800mAh cells while I got 2600mAh and 1000mAh cells, at least that's what the labels say. It doesn't surprise me that the sales information on websites aren't always up to date, but the power on screen does indeed state 35 in slot 4, which in my research seems to indicate v35. Whether there are any noticeable changes between v35 and v33 remains to be determined. Besides, wasn't there also some disconnect between TD's description of the C-9000's charge detection capabilities and Maha's website initially? I seem to recall the debate caused quite a run in one of the threads.



Easy KuoH,

It was just a heads up.

I would prefer that you're around a year from now so you can tell me I was right ...


----------



## KuoH (Jun 23, 2008)

Huh? No offense intended. I was just providing what I think is up to date information.

KuoH



Bones said:


> Easy KuoH,
> 
> It was just a heads up.


----------



## FrontRanger (Jun 23, 2008)

Black Rose said:


> Here is a thread that notes the firmware numbers.


 
Thanks for that, and for the BatteryUniversity.com link earlier.


----------



## TorchBoy (Jun 23, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



Bones said:


> It was implemented in the revision, as noted in Mr Happy's summary in post 62, and there was actually only one revision, as noted in the same post.


What is this post 62? Post 62 in this thread was by you, Bones. And that "firmware number thread" is really not the best one for that, since it doesn't mention all the changes.


----------



## NA8 (Jun 23, 2008)

Tempting price on the BC-700 currently in the Good Deals forum. :devil:

http://www.cpfmarketplace.com/mp/showthread.php?t=180204

Some nice pictures too.


----------



## Black Rose (Jun 23, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



TorchBoy said:


> What is this post 62? Post 62 in this thread was by you, Bones.


Look at post 62 again and you'll see that Bones pasted in a quote from a post that Mr. Happy made in a previous thread about this topic.



> And that "firmware number thread" is really not the best one for that, since it doesn't mention all the changes.


That was the first one I found using the less than perfect search function.


----------



## lengendcpf (Jun 23, 2008)

Hi, was going to get the C-9000 from Thomas Distributing.
But what put me off was the high shipping cost(cannot blame TD cause it is using Fedex..)

Then I read from another forum, actually there's a distributor in my own backyard(Singapore, Company is East gear). Selling at SGD86 for the charger.

Today, went and get the charger. At frst I asked to see what version, since I read here, version 0G is the current model, but I got the 0H0BA(which is the newest).

My manual is printed in 2008.

1. Charging Current : 0.2A to 2.0A in increments of 0.1A
2. Topoff Charging Current: 100mA
3. Maintenance Charging Current: 10mA - what is this, can anyone explain to me?
4. Discharge Termination: Voltage 0.90V
5. Discharging Current: 0.1A to 1.0A in increments of 0.1A
6. Capacity Storage Memory: 12 (Cycle mode only)
7. Supported Capacity: 100 to 20,000mAh
8. Charger Input Power: 12V 2.0A
Adapter Input: 100-240V 50/60Hz

First impression, it's huge(as compared to my other Sanyo charger). Needs an adapter(thought just an AC cable will do, but nevermind).

The backlit is bright, really can works as a night lamp(since the light will not go off) if going to charge overnight.

One thing as many user complained is the display can only be one at a time.

What I don't like is the 4 keys are not illuminated.


Overall, this is an excellent charger, since just now, I have played with it and charged 3 batteries..:twothumbs
.


----------



## bob_ninja (Jun 23, 2008)

SilverFox said:


> ....
> I might also point out that even though you charge a cell at a low rate and it doesn't heat up, that doesn't mean that overcharging damage is not occuring to your cells.
> .....



Tom, could you elaborate please?
Reading this forum I learned that heat is generated when input energy cannot be stored and is converted into heat which in turn can cause some damage. Hence super-quick 15 min chargers have fans.

Now when there is no heat present then what sort of damage can take place? How? Are there any other indications of damage besides heat?

thanks


----------



## KuoH (Jun 23, 2008)

According to the Batteryuniversity documentation linked one page back, "[FONT=Verdana, Arial, Helvetica, sans-serif]Lingering slow charges cause crystalline formation (memory)". I could easily be incorrect, but my understanding of this is that letting the cell sit on the charger for a prolonged period of time encourages crystal growth. What I'm still fuzzy on is whether this happens throughout the entire low current charging period, or occurs mostly after the cell is fully charged and the excess energy contributes to the growth.

As for detecting damage, since there is little heat and no other visible indicators, measuring the change in capacity would be the only method I can think of other than disassembling the cell and putting it under a microscope. I suppose that's also one of the reasons I prefer to charge at the low rates. I'm not in that much of a hurry most of the time and I'd much rather risk a low current overcharge than the same at high currents.

KuoH
[/FONT]


bob_ninja said:


> Now when there is no heat present then what sort of damage can take place? How? Are there any other indications of damage besides heat?


----------



## bob_ninja (Jun 23, 2008)

KuoH,

You are missing the main point altogether. Let me state that my preference is for lower rates and I used BC900 @200 many times in the past. These days I still use 200mA for NiCd AAs that are around 800 mAh, so about .25C

That being said, for the majority of NiMH AAs on C9K the 200 mA rates makes no sense at all.

I'll use the metaphor or a Ferrari car being C9000 (in terms of performance and not cost).
If you asked people how it handles at 40 km/h (200 mA) speed you'd get blank stares and nobody could answer. Clearly you don't get a Ferrari to drive so slow. Sure it can handle it, but it is not the primary goal. Similarly 200 mA rate is not significant for Maha designers and their customers. It is just there in case you really want it, such as for older NiCds.

Therefore, stop asking about 200 mA on C9000 as nobody uses it on a regular basis.

Now I don't like blasting my AAs with 2A either. So just as blasting AAs using 15min chargers at 7A is not the best idea, similarly using only 200 mA (0.1C rate) is also a poor idea. If you move up to say 500 mA or 800 mA (I use often) and find no heat is generated, then why bother with 200 mA???

In particular, you want to at least try to stay close to recommended 0.5C-1C
Now I cheat and often use say 800 mA (right now) on 2.5Ah cells (so about 0.3C). I detect no heat, so why bother with 200 mA? There is not reasonable logic to going to 0.1C unless doing breakin.

Conversly if you still want 200 mA, say to redistribute electrolyte or whatever, you have to accept the fact that the risk of termination miss is much higher. It doesn't mean that -dV wont be detected, just that risk is much higher that is may be missed. Therefore, considering the higher risk you have to take extra steps to ensure termination, such as timer, periodic temp check, or whatever.

The point is that while both chargers may very well still detect -dV or not, you need to have additional safeties, like a timer. Maybe the charger's timer is sufficient or not. Whatever.

So the bottom line is that people don't purchare C9000 for 200 mA rate and thus few can tell you how well it works. I find that better spacing and excellent charging method on C9000 tends to keep cells cooler so I go to higher rates. On BC900 where cells are packed closely I get bit more heat so I go to lower rates, maybe 500 mA up to 1A. Really any rate below 0.5C can be called "slow".

If you intened to use such a low rate most of the time then you probably should go with the cheaper BC900/700 that for the most part seems to handle it well. Mine never failed me yet. You just don't need C9000 then.


----------



## bob_ninja (Jun 23, 2008)

KuoH said:


> According to the Batteryuniversity documentation .....[/SIZE][/FONT]



I doubt you'll find any *CURRENT* information on slow charge rates effect on *CURRENT* NiMH technology such as LSD (Eneloops). A lot of older information/research was done on older NiCds, such as for space applications. Most modern applications use 0.5C to 1C rates.

My power packs for tools use 1C for older NiCd packs as well as newer LiIon.
Curiosly, a new tool that has a Lithium Ion pack using 1.6Ah cells uses 200mA rate. Same goes for B&D VPX using A123 cells 1.1Ah at 200 mA rate.
In both cases I believe they use a simple peak detection.

However, for NiCd and NiMH I don't remember seeing any recent pack/cell/charger using anything below 0.5C.

Odds are both BC900 and C9000 are state of the art chargers for NiMH. If they cannot detect -dV at 200 mA then no other charger can.


----------



## AlexLED (Jun 23, 2008)

bob_ninja said:


> Tom, could you elaborate please?
> Reading this forum I learned that heat is generated when input energy cannot be stored and is converted into heat which in turn can cause some damage. Hence super-quick 15 min chargers have fans.
> 
> Now when there is no heat present then what sort of damage can take place? How? Are there any other indications of damage besides heat?
> ...



It's true that a battery convert the energy you charge into it into heat, once it's fully charged. And the heat itself is deteriorating to the chemistry. But if the current is low, the heat generated is not enough to actually raise the temperature of the cell. 
But still, the current itself has effects on the chemistry. If I understand correctly, it's the oxygen formed at the positive electrode. Excess oxygen formed due to overcharge, whether at high or low currents is deteriorating as well. 

For more details, have a look at the Twicell Guide by Sanyo. 
http://us.sanyo.com/batteries/pdfs/twicellT_E.pdf


----------



## bob_ninja (Jun 23, 2008)

AlexLED said:


> It's true that a battery convert the energy you charge into it into heat, once it's fully charged. And the heat itself is deteriorating to the chemistry. But if the current is low, the heat generated is not enough to actually raise the temperature of the cell.
> But still, the current itself has effects on the chemistry. If I understand correctly, it's the oxygen formed at the positive electrode. Excess oxygen formed due to overcharge, whether at high or low currents is deteriorating as well.
> 
> For more details, have a look at the Twicell Guide by Sanyo.
> http://us.sanyo.com/batteries/pdfs/twicellT_E.pdf



Right, pressure buildup that can cause venting. Still, you could inspect the seal and see if venting took place. Besides at sich as low rate (0.1C and lower) I don't think there would be much pressure buildup and venting.

I am not sure I see how could you have excess oxygen cause venting WITHOUT heat.


----------



## KuoH (Jun 23, 2008)

Well it is your prerogative to see it anyway you like, but my intention was to find out what each charger did as well, better or worse than the other. I thought that's what the title of this thread was about? What I have seen so far is that most owners of both units seem to agree that neither have much of a problem with proper charging behavior at high currents, albeit the BC-900 suffers a handicap on the highest available current and the 2 cell limit at that end. But at the other end of the spectrum, the C-9000 advocates seem all over the board with responses like, "no there isn't a problem", "yes there is, but it's fixed trust me", or your current response "there may or may not be a problem, but you shouldn't be using it in that manner anyway." I was simply clarifying some details in order to make my own determination.

To use your own example, the Ferrari owner has to drive through a school zone eventually doesn't he? Or are you saying he should never go anywhere where he can't drive fast? And if he should say that the car often stalls or the brakes sometimes fail when he drives at below 100MPH, doesn't that give you a different perspective on owning one even if you could afford it?

I know full well people don't buy the C-9000 for the 200mA feature, but it's there and if it can't be used effectively, then perhaps it shouldn't be there? The safety timer issue is also something I mentioned, in that as it's implemented so far, it does not seem at all safe on the C-9000 given it's primary role as an AA and AAA charger.

Now as far as cooking my cells on a regular basis, I have tried 500mA and 1A rates and some of my cells seem fine, but others have hit the thermal safety limit at 1A and were quite uncomfortable to hold. Just one or two such occurrences coupled with a missed termination could well be enough to destroy or severely cripple an otherwise still usable cell. Now some members simply advocate "recycling" such cells, but my use of them is not so demanding that they all have to be capable of .5C and 80% or better capacity, and I suspect there are others who feel similarly, though perhaps not here on CPF. With these smart charger/analyzers, I could easily feed all the remote controls and more in my house on the marginal cells. even if I have to change them out every month instead of every other month, so what?

You are correct in your assessment that I may not need the C-9000. In fact, that's why I decided on two BC-900's instead. But, that doesn't mean that I can't offer my opinions on the matter, and perhaps try to contribute to making the successor models of both chargers closer to my expectations, assuming I'm not asking for something that is detrimental to it's design purpose.

KuoH



bob_ninja said:


> KuoH,
> 
> You are missing the main point altogether. Let me state that my preference is for lower rates and I used BC900 @200 many times in the past. These days I still use 200mA for NiCd AAs that are around 800 mAh, so about .25C
> 
> ...


----------



## KuoH (Jun 23, 2008)

I don't think he was referring specifically to venting of the oxygen. On the bottom of page 8 of his link, it states "If a battery is overcharged and the negative electrode consumes oxygen gas formed at the positive electrode, the hydrogen absorbing alloy will become partially oxidized and will deteriorate the performance of the negative electrode." It does not state, at least I haven't found mentioned in the document, that the effect is only exhibited at high currents. Simply that repeated overcharges will result in the deterioration.

KuoH



bob_ninja said:


> I am not sure I see how could you have excess oxygen cause venting WITHOUT heat.


----------



## Unforgiven (Jun 23, 2008)

KuoH,

Perhaps some are responding to you in the ways that they are because they get the impression that you are more interested in an argument rather than any logical conclusion. How ideas are presented on a forum determines whether or not the community views one as a respected member or something else. 


Maybe it's just a communication issue? 


It's something worth considering.


----------



## KuoH (Jun 23, 2008)

Thanks for the friendly advice. I do wonder however, might not the same be said for some of the other respondents? I have reread my first few contributions to this thread and to be perfectly honest, they seem about as diplomatic and PC as I am capable of making them at this point. Feel free to point out how I might have approached the subject more delicately, by PM if necessary, lest I take up anymore bandwidth here than I already have.

I suppose the anonymous and impassive nature of the internet does make it possible for the communications and intent of all but the most careful amongst us to be more easily misconstrued. If anyone has taken offense or come to the impression that I wanted an argument, I hereby apologize and state categorically that those were not my intent. However, the engineering flunky side of me does tend to push for and expect myself to provide thorough and logical answers and correspondingly, ask similar questions. This may not be the forum to expect definitive answers from unassailable sources for those questions, but I hope that doesn't mean that I can't ask.

KuoH



Unforgiven said:


> Perhaps some are responding to you in the ways that they are because they get the impression that you are more interested in an argument rather than any logical conclusion. How ideas are presented on a forum determines whether or not the community views one as a respected member or something else.
> 
> 
> Maybe it's just a communication issue?


----------



## N162E (Jun 23, 2008)

KuoH said:


> I see where a couple of individuals mentioned that they tested the low charge rate termination once, but didn't follow-up with any repeated or long term results at the lower levels.
> KuoH


I have tested again and again and again and My C-9000 will NOT dependably terminate anywhere under 600ma and not at all below 400 ma. My LaCross's will terminate everytime at 200ma on dv. If in fact the newer Mahas actually terminate at a certain voltage and continue to charge at a lower rate for 2 more hours that should be reason enought to not purchase the Maha. If the C-9000 is not able to sense dv I don't want it.


----------



## N162E (Jun 23, 2008)

bob_ninja said:


> KuoH,
> 
> Therefore, stop asking about 200 mA on C9000 as nobody uses it on a regular basis.


I use 200ma all the time. Longer slower charging is better. I do not do it on the C-9000 for two reasons, it is a pain to program each slot to handle 200ma, secondly the C-9000 will not terminate on Dv at 200ma. I prefer a charger that can deliver accurate charging at all rates.


----------



## Black Rose (Jun 23, 2008)

N162E said:


> I have tested again and again and again and My C-9000 will NOT dependably terminate anywhere under 600ma and not at all below 400 ma.


But you have two older C9000 units (0FAB01) which do not have the updated firmware to address that particular issue, so they won't detect it reliably.

It will be interesting to see the results KuoH gets with his V35 BC-900. 

I currently have some 1400 mAh cells on the C9000 that are in the last part of a cycle test. 
When they are done, I'll put the cells I tested earlier in this thread (2000 mAh ROV) on the C9000 @ 200 mA after I discharge them. 
Then we'll see what happens with a C9000 that has the revised firmware (0G0KA) to addressed the termination and repeating digit issues.


----------



## N162E (Jun 23, 2008)

Black Rose said:


> But you have two older C9000 units (0FAB01) which do not have the updated firmware to address that particular issue, so they won't detect it reliably.
> 
> It will be interesting to see the results KuoH gets with his V35 BC-900.


This is true but, it dosen't sound to me like the newer ones detect end of charge either. If the new ones are terminating at a specific voltage that voltage may or may not be a full charge. Most cheap chargers seem pretty able to pick up a termination signal but the expensive C-9000 can't?


----------



## KuoH (Jun 23, 2008)

I have 4 of what would be considered problem AA cells, which consistently report less than 50% of the original capacity in the v35 now at 200mA. Given the time it takes to charge, I'm not having good luck catching all of them at the end of cycle to confirm -dv termination, but the ones I have seen so far have not been due to voltage or time limits. The other charger is busy doing 500mA and 1000mA tests, and I'm finding a couple of cells which are surprisingly over the labeled capacity. I'm going to retest these to see if I'm just lucky or if my BC-900's are overly optimistic.

EDIT: Another cell just finished a 200mA refresh cycle at 1.41V in 3:30. Suffice it to say that it doesn't have much usable capacity left, but it does tell me that the charger didn't terminate on voltage, time or temperature limits in this case. Might as well see what 500mA and 1000mA will do to it, since it can't get much worse.

KuoH



Black Rose said:


> It will be interesting to see the results KuoH gets
> with his V35 BC-900.


----------



## NA8 (Jun 23, 2008)

KuoH said:


> I have 4 of what would be considered problem AA cells, which consistently report less than 50% of the original capacity in the v35 now at 200mA.
> 
> KuoH



I've found using an indoor/outdoor thermometer probe on one of the batteries is helpfull in keeping an eye on the charge process. I've got an Oregon Scientific model (Target $13, Fry's, etc) that has min and max memory readings so even if I miss the termination, I can check the peak temperature reading and have a good idea if it terminated before or after it should have. You can also watch the rapid temp rise and see when the battery is approaching termination (hopefully). The BC-900 has a high temp cut off mode: 

"The Temperature Sensor Circuit built in to the BC-900 will stop the charge cycle if the battery temperatures reach 127°F. As soon as the batteries have cooled the automatic charging will resume. This feature will greatly maximize the life of your rechargeable batteries when dangerous overheating is prevented." 

If you see the temps going over 127F without stopping, you know you have a problem. If your max temp reading was around 125 or so, you probably have a sick battery.


----------



## TorchBoy (Jun 23, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



lengendcpf said:


> Today, went and get the charger. At frst I asked to see what version, since I read here, version 0G is the current model, but I got the 0H0BA(which is the newest).


Nice. That has the (at least) third firmware version.

N162E, I take my hat off at you still using the original MH-C9000 firmware. Have you considered exchanging them? They're still under warranty.


----------



## 45/70 (Jun 24, 2008)

OK, I admit, I didn't read many posts in this thread. Hey! It's a poll, right?  

Anyway, I couldn't vote because I use both. I use the BC-900 most of the time as a charger, and I use the C-9000 for analyzing, break in etc. The C-9000 will charge at a faster rate, especially with 3-4 cells, but I rarely charge at a faster rate than 1000mA anyway. Even so the BC-900 is actually faster, because you don't have to wait 2 hours after they're "DONE" for the "top off" charge to finish, as you do with the C-9000. The C-9000 does seem to keep the cells cooler, but at 1000mA it's not a big deal.

Dave


----------



## lengendcpf (Jun 24, 2008)

By the way, regarding the C-9000 not terminating at lower charge current.. How I do I know if it has terminated? Cause I put in a cell, after charging, at the slot number' s right hand, it will show DONE. But I can still see some current will still be pumping in.

Is it after 2 hours of topping(Also I can't see any 2 hours of topping in the manual.. how you guys know?), the current will stop showing?

Or what will the display show?


----------



## TorchBoy (Jun 24, 2008)

Hi lengendcpf. The voltage starts to drop, instead of holding steady or climbing, so instead of 1.51 it'll stop back to 1.46, which I think is where the trickle charge keeps it.


----------



## lengendcpf (Jun 24, 2008)

45/70 said:


> OK, I admit, I didn't read many posts in this thread. Hey! It's a poll, right?
> 
> Anyway, I couldn't vote because I use both. I use the BC-900 most of the time as a charger, and I use the C-9000 for analyzing, break in etc. The C-9000 will charge at a faster rate, especially with 3-4 cells, but I rarely charge at a faster rate than 1000mA anyway. Even so the BC-900 is actually faster, because you don't have to wait 2 hours after they're "DONE" for the "top off" charge to finish, as you do with the C-9000. The C-9000 does seem to keep the cells cooler, but at 1000mA it's not a big deal.
> 
> Dave


 
I thought as long the C-9000 shows DONE for the individual slot, that particular charging is completed? My sanyo charger also has the trickling charge after the charging is completed(i.e. the led goes off for that channel). Don't the BC-900 have it?


----------



## lengendcpf (Jun 24, 2008)

lengendcpf said:


> 2. Topoff Charging Current: 100mA
> 3. Maintenance Charging Current: 10mA.


 
Answer my own questions:

Topoff Charging Current: An intermediate, medium current, top-off charge so that the battery will retain most of its charge.

Maintenance Charging Current: The Maintenance Charging feature is an extremely low current pulse charging that gives the batteries a brief pulse charge periodically to ensure the batteries are charged but not overcharged.


----------



## N162E (Jun 24, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



TorchBoy said:


> Nice. That has the (at least) third firmware version.
> 
> N162E, I take my hat off at you still using the original MH-C9000 firmware. Have you considered exchanging them? They're still under warranty.


No I had not, Thank you for that bit of info. I was not aware they had a 3 year warranty. I just may keep them though. I like they way they work at 700+ma which I use sometimes. From a charging standpoint I like the LaCrosse's better, for maintenance I like My C-9000s the way they are.

Thanks for that info Torchboy


----------



## TorchBoy (Jun 24, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*

N162E, apart from the "termination roasting" (as I called it) the original firmware also handled discharges differently, where it decreased the discharge current as the cell discharged, sometimes down to a just a few mA, and terminated at 1.0V (unloaded?) many hours later than it should have thanks to the reduced current.

The later firmware holds a constant discharge current until it terminates at 0.9V loaded, in the timeframe expected with a 90% duty cycle.


----------



## Black Rose (Jun 24, 2008)

Black Rose said:


> I currently have some 1400 mAh cells on the C9000 that are in the last part of a cycle test.
> When they are done, I'll put the cells I tested earlier in this thread (2000 mAh ROV) on the C9000 @ 200 mA after I discharge them.
> Then we'll see what happens with a C9000 that has the revised firmware (0G0KA) to addressed the termination and repeating digit issues.


OK, testing has finished.

Summary of the test conditions: 

Four 2000 mAh Rayovac NiMh batteries (non-LSD) previously charged at 500 mAh several days ago and removed from charger. Cells were then discharged at 1000 mAh, rested in charger for 5 or 6 hours, and finally charged at 200 mA on a C9000 with the revised firmware.


```
Battery   Terminated  Charge Applied   Minutes To Terminate
1             Y           2014 mAh           666
2             Y           2334 mAh           775
3             Y           2313 mAh           767
4             Y           2278 mAh           746
```
 
Battery #1 has approximately 11% less capacity than the other three batteries, so that's why it finished quicker than the others. 
This could potentially be considered a "crap" cell for this test.

That is only two tests performed on this same set of batteries at low charge rates, so not 100% conclusive.







EDIT: In case anyone is wondering, the red thing the C9000 and C800S are sitting on a flexible silicone baking mat.


----------



## FrontRanger (Jun 25, 2008)

Black Rose said:


> In case anyone is wondering, the red thing the C9000 and C800S are sitting on a flexible silicone baking mat.


 
Just got my C9000 in the mail a couple days ago and haven't had a chance to use it yet. Does it really dissipate so much heat that you need the baking mat for heat conduction? Or is it just there as a protective layer in case of a battery venting accident? Thanks.


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## N162E (Jun 25, 2008)

FrontRanger said:


> Just got my C9000 in the mail a couple days ago and haven't had a chance to use it yet. Does it really dissipate so much heat that you need the baking mat for heat conduction? Or is it just there as a protective layer in case of a battery venting accident? Thanks.


.............or, in case the charger itself catches fire. This is good common sense with any small appliance that is going to run for hours at a time not always watched.


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## digitor (Jun 25, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*



TorchBoy said:


> N162E, apart from the "termination roasting" (as I called it) the original firmware also handled discharges differently, where it decreased the discharge current as the cell discharged, sometimes down to a just a few mA, and terminated at 1.0V (unloaded?) many hours later than it should have thanks to the reduced current.
> 
> The later firmware holds a constant discharge current until it terminates at 0.9V loaded, in the timeframe expected with a 90% duty cycle.



This is not quite correct, although it is the symptom with high impedance cells. I still use an original C9000, and the discharge works as expected (constant current until termination) with healthy cells. 

The difference is, it measures the discharge voltage off-load, so with a high impedance cell, the voltage will bounce back in the unloaded condition, and the discharge won't terminate as soon as it should. The on-load voltage drops to a level where the cell is unable to sustain the programmed discharge rate, hence you get the decreasing current. (termination voltage is 1V, as you stated, TorchBoy).

The new revision measures under load, and terminates at 0.9V.

Cheers


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## TorchBoy (Jun 25, 2008)

*Re: Maha MH-C9000 vs. La Crosse BC-900*

Thanks digitor, that's an important clarification.


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## Black Rose (Jun 25, 2008)

FrontRanger said:


> Just got my C9000 in the mail a couple days ago and haven't had a chance to use it yet. Does it really dissipate so much heat that you need the baking mat for heat conduction? Or is it just there as a protective layer in case of a battery venting accident? Thanks.


Just an extra level of protection, since the various chargers do produce a certain level of heat, and should something go wrong, they won't be in direct contact with wood, etc.


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