# LaCrosse BC-900 vs LaCrosse BC-700



## tsu3000 (Apr 13, 2008)

Hi

I cannot decide which LaCrosse charger to buy and hope someone can give me some advice. 

I have read some user reviews (Amazon etc) about the BC-900 melting batteries, but under what conditions is a bit unclear. Also one reviewer said that the newer V33 also melts batteries. Hopefully someone will shed some light on this.

With this in mind, I thought about getting the BC-700 which does not seem to be as popular and has less charging currents. But I have not seen any reviews of it malfunctioning or melting batteries. Has the BC-700 been redesigned to be more reliable than the BC-900 or do they still share the same charging circuits, algorithms etc. with the potential to still melt batteries if the right conditions are met?

I'd much rather get a "lesser" charger with the knowledge that they will not melt my batteries than get one that has the potential cook batteries/charger.

I plan to use Sanyo Eneloops using a low current (maybe 500mAh). Both models fit the bill. But which one do you recommend? Is the extra 1000mAh charging current on the BC-900 ever needed in practice now that Eneloop or equivalents are available.

Thanks in advance.

J


----------



## Raymond (Apr 13, 2008)

Hi, and welcome 

There have been a few discussions on the BC-700 (use the google searchbox at the top of the page, not the forumsearchbox at the bottom).

The chargers seem to be identical, except for the chargingcurrents. Pricedifference is next to nothing: http://thomasdistributing.com/shop/index.php?cPath=147_149_152&sort=3a&filter_id=23

$34 vs $39

I think the higher charging current of the 900 is nice to have. But if you're not comfortable with that charger, just go for the 700


----------



## geek4christ (Apr 13, 2008)

Hi tsu3000,

Let me start by saying :welcome: 

I would recommend the BC-900, for the ability to charge at higher rates as Raymond mentioned. It is easier to charge in the recommended .5C to 1C range on the BC-900. This means your cells will give a more reliable end-of-charge signal, and it's less likely the charger will miss termination and ruin them.


----------



## tsu3000 (Apr 14, 2008)

Hi

Thanks for the replies. Excuse my ignorance but what does ".5 to 1C" mean? Are there links available to explain the terminology? I am new to all of this .

I will probably use Eneloop 2000mAh batteries or Sanyo 2700mAh batteries for the LaCrosse. Are these batteries recommended for the LaCrosse?

Thanks in advance.


----------



## worldedit (Apr 14, 2008)

Could i charge D cells with the BC-900? I connected one to my BC-700 and it always stops chargen after reaching a fixed charge. Does the BC-900 have the same protection?
Can i wire two or more of the charging channels in parallel to charge higher capacity cells?


----------



## geek4christ (Apr 14, 2008)

tsu3000 said:


> Hi
> 
> Thanks for the replies. Excuse my ignorance but what does ".5 to 1C" mean? Are there links available to explain the terminology? I am new to all of this .
> 
> ...



The C rate is a function of the charge current and battery capacity. If you charge a cell with a capacity of 2000mAh at a 1000mA charge rate, then you are charging at .5C. Likewise, charging that same cell at 2000mA is charging at 1C.

There is a lot of good information in The Welcome Mat about this and many other topics. It's a good place to start your flashaholism 

In an ideal circuit with no losses (not actually attainable), charging at 1C would mean your cell gets charged in an hour, 2 hours for .5C. In the real world, it will take a little longer than that to charge.

Those batteries will be fine for the chargers in question. Just stick them on to charge at the 1000mA rate.

One thing to note is that the LaCrosse chargers have a reputation for heating up too much. It's a good idea to put the charger in a baking dish or on some other non-flammable surface away from things that could burn. I have my BC-900 sitting on a large ceramic tile :thumbsup:


----------



## geek4christ (Apr 14, 2008)

worldedit said:


> Could i charge D cells with the BC-900? I connected one to my BC-700 and it always stops chargen after reaching a fixed charge. Does the BC-900 have the same protection?
> Can i wire two or more of the charging channels in parallel to charge higher capacity cells?



What is the capacity of your D cells? I believe the BC-900 stops charging after putting 3000mAh into a cell. There may be something similar in the BC-700 that you are running into.


----------



## SilverFox (Apr 14, 2008)

Hello Tsu,

Welcome to CPF.

When you charge at 1C, your charge time is about 1 hour. When you charge at 0.5C, your charge time is about 2 hours.

This range of charging rates is what the battery manufacturers recommend when using a charger that uses a -dV signal to terminate the charge. Slower rates generate a weaker end of charge signal, and you run the risk of damaging your cell through overcharging.

Eneloop cells have a capacity of 2000 mAh. A 1C charge rate would be 2000 mA. A 0.5C charge rate would be 1000 mA.

The LaCrosse chargers utilize -dV termination, along with a few other back ups.

Keep in mind that it is possible to charge at lower rates, but you run a risk of damaging your cells due to overcharging.

Tom


----------



## tsu3000 (Apr 14, 2008)

Thanks everyone for your time in posting replies - its much appreciated.

So would you say that the min charging current to avoid issues of mis-termination and overcharging is 1000mA for the BC-900? Or is this an over simplification? If 1000mA is indeed recommended then it begs the question: what is the point of the other lower currents (esp 200mA) if they can cause problems with cooked batteries/charger?

Having a metal plate etc under the charger and installing fans is a good precaution but its seems over the top for a product that is suppose to "just work" out of the box.

I am beginning to think whether the LaCrosse range of charger is worth bothering with.

Thanks in advance.


----------



## SilverFox (Apr 14, 2008)

Hello Tsu,

There is another charge rate that the battery manufacturers recommend. Starting with a discharged cell, you can charge it at 0.1C for 16 hours. This is a timed charge. The charge is terminated at the end of 16 hours.

With an Eneloop 2000 mAh cell, the 0.1C rate is 200 mA. Since the BC-900 has a safety shut off at around 3000 mAh, you may be able to use the 200 mA rate if your cells are completely discharged prior to charging. 

The problem with this is that if the charger has -dV sensing termination, the charge may be aborted before the cells are charged. This is known as a false peak.

Another problem is what to do with a cell that is only partially discharged. The 0.1C rate is supposed to be low enough that any damage from overcharging at that rate is minimal, so that may not be a big issue.

Another safety used is maximum voltage. The charger will quite charging when the cell voltage reaches a maximum value. This method of charge termination is hardest on new cells, and won't completely charge older cells, unless a top off charge is added to the main charge.

As you can see, there are several ways to charge, and terminate the charge. It seems like each charger has strong, and weak points. You have to decide what charger has the possibility of doing the best job of charging your batteries, without destroying them. You then have to settle on a price that you are willing to pay, and evaluate the price/performance ratio of your charger. 

If you charge batteries twice a year, you can get by with a charger that does not treat your batteries all that well. However, if you charge batteries twice a day, charging without damage becomes very important.

I have a BC-900 and used it a lot before the Maha C9000 came out. I had it on a heat resistant surface, and usually charged at 1000 or 1500 mA. I like the features of the C9000, so my BC-900 is not in retirement. My C9000 is also on a heat resistant surface, as are the other chargers that I use.

Good luck on your choice...  

Tom


----------



## tsu3000 (Apr 15, 2008)

Hi SilverFox

Thanks for the info. Its much appreciated.

I will probably get the BC-900 in the end since I think its the most comprehensive charger for the price. The C9000 is a bit too much for me and I will probably never use half the available functions it offers.

If I stick with Eneloop's and charge sensibly and take proper precautions I think the BC-900 will be pretty reliable.

How hot do the Eneloop's get when using the BC-900 say when using 1000mAh rate?

tsu


----------



## SilverFox (Apr 15, 2008)

Hello Tsu,

They warm up a little, but don't get hot.

They should do just fine charging on the BC-900.

Tom


----------



## N162E (Apr 15, 2008)

SilverFox said:


> Most batteries don't die - they are tortured to near death, then murdered...Tom


Our motto


----------



## SilverFox (Apr 15, 2008)

Hello Fred,

 

Tom


----------



## NA8 (Apr 16, 2008)

LaCrosse
$46.32 with economy shipping.

Maha C90000
$59.97 with free shipping. 

http://www.thomasdistributing.com/index.htm


The difference is $13.65. 

For $13.65 you're going to buy a product with a long history of problems ? 

Mine hasn't melted, but it has a knack for shutting down due to "over temperature" until it cools off and then starts charging again. That sound like the way you want to go ? 

Does the Maha give you an extra $13.65's worth of value ? You decide, take a look here: 

https://www.candlepowerforums.com/posts/1761060&postcount=37

Which do you want to invest your money in ?


----------



## bryaninperson (Apr 16, 2008)

I was in your shoes on trying to decide a few weeks ago. I went with the LaCrosse BC-900. I am glad I did. Very easy to use and what little I have used it, it is going strong. The deciding factor for me was the extras you get with BC-900. However, I did a test on the AAA's and three were good pushing close to the 800 mAh capacity and one was only at 330 mAh. Now I have a chance to use the refresh function on that battery. I am very happy with the BC-900.


----------



## geek4christ (Apr 16, 2008)

NA8 said:


> Mine hasn't melted, but it has a knack for shutting down due to "over temperature" until it cools off and then starts charging again. That sound like the way you want to go ?



While that is a huge pain, I get around it by keeping a small fan blowing on mine. I know I shouldn't *have* to do that, but it's not too inconvenient since my charger is in my junky office anyway.

I haven't had mine very long, but the fan does keep the cells nice and cool and I haven't missed a termination yet, FWIW.


----------



## N162E (Apr 16, 2008)

NA8 said:


> LaCrosse
> $46.32 with economy shipping.
> 
> For $13.65 you're going to buy a product with a long history of problems ?
> ...


What charge rate are you using? I really like the default 200mah rate, very little heat at that rate. I also use 500 and 700 when I'm in a hurry, the batteries tend to get warmer toward the end but not what I would call hot.




NA8 said:


> Does the Maha give you an extra $13.65's worth of value ? You decide, take a look here:
> 
> https://www.candlepowerforums.com/posts/1761060&postcount=37


It gives you a lot more work to do at almost twice the size.



NA8 said:


> Which do you want to invest your money in ?


I use both. I do all my charging on the LaCrosse and my Discharging on the MAHA C-9000. My PERSONAL experience is that while the standard nimh cells seem to thrive on being "Beat Up" the newer LSD'S seem to do just fine with gentler handling.


----------



## sandbasser (Apr 16, 2008)

Disregard...


----------



## NA8 (Apr 17, 2008)

N162E said:


> What charge rate are you using?



I ran into the over temp/cool down mode while charging at 1Amp. Going to 700mA works much better esp for just one or two batteries. I think that's why you see the 700mA limit on the BC-700 model. It's never been clear to me if they're still making the BC-900 model or if they just had a lot of stock left. I'd hope the BC-700's are actually the old BC-900 circuit boards, and the "new" BC-900's have some sort of improved design, but LaCrosse is keeping quiet about all that. 




N162E said:


> It gives you a lot more work to do at almost twice the size.



I got around that problem by buying the C808M.


----------



## NA8 (Apr 17, 2008)

geek4christ said:


> While that is a huge pain, I get around it by keeping a small fan blowing on mine. I know I shouldn't *have* to do that, but it's not too inconvenient since my charger is in my junky office anyway.
> 
> I haven't had mine very long, but the fan does keep the cells nice and cool and I haven't missed a termination yet, FWIW.



The only concern I have there is that you might be simply keeping the surface of the cells and the metal bands that connect the BC-900's temperature sensors to the batteries nice and cool (keeping the unit running), but the actual temperatures at the core of the batteries may still be rather excessive. The tiny mosfets in the BC-900 might be getting pretty warm too. I'm not an expert though. Just a thought I had.


----------



## geek4christ (Apr 17, 2008)

NA8 said:


> The only concern I have there is that you might be simply keeping the surface of the cells and the metal bands that connect the BC-900's temperature sensors to the batteries nice and cool (keeping the unit running), but the actual temperatures at the core of the batteries may still be rather excessive. The tiny mosfets in the BC-900 might be getting pretty warm too. I'm not an expert though. Just a thought I had.



That's a good point. It could very well be crazy hot inside the cells.

I'm just thinking that through and wondering...wouldn't it be the case that the only way that could happen is a really high internal resistance in the cells? If the charger circuitry isn't contributing any heat to the cells, that's my best guess anyway.


----------



## shadowjk (Apr 17, 2008)

For most of the duration of charging, I've found that the actual charger runs hotter than the cells... That makes me want to construct some sort of contraption that would blow air at the charger from below, so that the charger runs the coolest.


----------



## NA8 (Apr 18, 2008)

geek4christ said:


> ...wouldn't it be the case that the only way that could happen is a really high internal resistance in the cells? If the charger circuitry isn't contributing any heat to the cells, that's my best guess anyway.



I've seen a few posts where people have suggested the charger is heating up the batteries. I've noticed my maha C808M has very low battery temps in comparison. (I've gotten into the habit of placing an indoor/outdoor thermometer probe on one of the batteries.) Newer design chargers (maha's) spread the batteries apart much more which helps. If you notice, LaCrosse suggests using slots 1 and 4 when charging 2 batteries.


----------



## geek4christ (Apr 18, 2008)

NA8 said:


> (I've gotten into the habit of placing an indoor/outdoor thermometer probe on one of the batteries.)



That's cool, I might have to get one of those. That would be less expensive than buying a full-on thermocouple adapter to go on my DMM.


----------



## warlord (Apr 18, 2008)

I'm really cheap. I had a hard enough time spending $17 on Eneloops even though I know it's a good deal. I was just going to charge them in a cheap Rayovac walmart charger. The last brand new one I bought (just a couple weeks ago) overheated and melted one of the AAA's I was charging into it...

So I splurged (for me) and bought a bc-700 for $32 shipped. Hopefully I don't ruin those new Eneloops. I also *hope* you battery gurus will tell me it's a lot better to use than one of those generic 2cell timed chargers...


----------



## warlord (Apr 18, 2008)

Uh.... or not? I ordered @ Amazon so I can still cancel...


----------



## NA8 (Apr 18, 2008)

warlord said:


> So I splurged (for me) and bought a bc-700 for $32 shipped. Hopefully I don't ruin those new Eneloops. I also *hope* you battery gurus will tell me it's a lot better to use than one of those generic 2cell timed chargers...



It should be much better


----------



## geek4christ (Apr 18, 2008)

warlord said:


> I'm really cheap. I had a hard enough time spending $17 on Eneloops even though I know it's a good deal. I was just going to charge them in a cheap Rayovac walmart charger. The last brand new one I bought (just a couple weeks ago) overheated and melted one of the AAA's I was charging into it...
> 
> So I splurged (for me) and bought a bc-700 for $32 shipped. Hopefully I don't ruin those new Eneloops. I also *hope* you battery gurus will tell me it's a lot better to use than one of those generic 2cell timed chargers...



Timed chargers aren't terrible as long as you run the batteries down fully before putting them on. It depends on if you need the quick charge or not, and whether you need the ability to top off a half-discharged battery (which you shouldn't do on a timed charger). They're definitely not robust, but they have their place in the world.

The BC-700 has many features that you'll like if you want to know the capacities of your batteries -- and if you like menus and buttons :devil:


----------



## warlord (Apr 18, 2008)

I think I'd like to be able to top off batteries, check capacities, and refresh/test/discharge. I just wanted to make sure I'm not going to ruin my nice new batteries because the 700 can't do .5C with the Eneloops.


----------



## N162E (Apr 18, 2008)

warlord said:


> Uh.... or not? I ordered @ Amazon so I sill cancel...


Simply Stated, you are guilty of buying one of the best and most versatile chargers available. No opinions just facts, I have two BC-900s bought when they first came out, they are flawless and will terminate every time at all their charge rates. Yes, they will terminate reliably at 200ma. The few previous problems reported with this charger took place with cheap cells, the charger was modified or a different wall wart was used. I don't recall a problem with any of the LSDs.


----------



## Ayeaux (Apr 18, 2008)

I also got a BC-700 because I got a better deal on it than a BC-900 at the time. So far it has worked just fine with my eneloops. I have charged at 200 and 700 ma and haven't missed a termination yet on the eneloops. 
I will say that it has missed termination on much older, well used NIMH that I've had laying around for several years.


----------



## warlord (Apr 19, 2008)

Thanks, all. Now I can't wait until my charger comes in so I can start messing around with some of my old batteries!


----------



## warlord (Apr 23, 2008)

OMG, my BC-700 got here already. I just ordered it on Saturday (19th) and it's already here with the free shipping. 

I'm already having fun refreshing some old NiMH batteries I had laying around.:twothumbs


----------



## bill_n_opus (Apr 24, 2008)

Have fun ... I know that when I first got my bc-900 I was like:

"oooh .. what's the voltage?!"

My wife thinks i'm nuts.


----------



## N162E (Apr 24, 2008)

warlord said:


> OMG, my BC-700 got here already. I'm already having fun refreshing some old NiMH batteries I had laying around.:twothumbs


Imagine the fun your'e going to have when you get rid of all those old batteries and replace them ALL with newer LSD batteries.


----------



## warlord (Apr 24, 2008)

bill_n_opus said:


> Have fun ... I know that when I first got my bc-900 I was like:
> 
> "oooh .. what's the voltage?!"
> 
> My wife thinks i'm nuts.



Yeah, it's easy to get a bit overzealous with the new toys.



N162E said:


> Imagine the fun your'e going to have when you get rid of all those old batteries and replace them ALL with newer LSD batteries.



I'm already not impressed with some early results from the old NiMH batteries I've been using. One pair of 2500mAh cells only charged to about 1500mAh on the first refresh cycle.

Anyway, I don't forsee getting rid of *ALL* the old cells since they go through a pretty rapid discharge/recharge rotation powering my xbox controllers. It's the perfect task for those old/cheap NiMH batteries. My eneloops however will be put to work in my flashlights, some of which may sit for a while between uses.


----------



## Black Rose (Apr 24, 2008)

When I got my C9000, I was amazed to see just how poor some of the cells I have were...several of my 2000 mAh cells lost massive amounts of capacity.

Looking back on it now, I didn't realize that NiMh cells self discharged when I bought a bunch of them at once. When I went to use them they were too low or dead, so I got into the habit of topping them up. Kept them charged for use, but slowly killed some of them.

LSD cells are what I really needed, just wasn't aware of them at the time. 

I've pretty much replaced all my non-LSD cells with LSD ones. 
All my good non-LSD cells will be given away, the rest will be recycled.


----------



## Muse (Mar 13, 2012)

geek4christ said:


> While that is a huge pain, I get around it by keeping a small fan blowing on mine. I know I shouldn't *have* to do that, but it's not too inconvenient since my charger is in my junky office anyway.
> 
> I haven't had mine very long, but the fan does keep the cells nice and cool and I haven't missed a termination yet, FWIW.


I went to the trouble of constructing a special charging stand with ventilation with a fan on top for my BC-900. I charge both AAs and AAAs, and lately eneloops exclusively. When I posted here describing my charging stand with fan people said I shouldn't use it, that the cooling fan would increase the likelihood of the BC-900 from missing termination. So, I've unplugged the fan, still use the stand. They also said to never use the 200ma charge rate, which increased the likelihood of missed termination, that I should use 500ma. However, some posts here have me wondering if I should be using 1000ma. Is all this true of the BC-700?

I'm contemplating getting a BC-700 in addition now, for a 2nd charger. Is it as good as the BC-900? I saw some posts at Amazon suggesting that the difference is essentially that the BC-900 comes with batteries and C and D cell adaptors. I need neither.


----------



## ChrisGarrett (Mar 14, 2012)

Muse said:


> I went to the trouble of constructing a special charging stand with ventilation with a fan on top for my BC-900. I charge both AAs and AAAs, and lately eneloops exclusively. When I posted here describing my charging stand with fan people said I shouldn't use it, that the cooling fan would increase the likelihood of the BC-900 from missing termination. So, I've unplugged the fan, still use the stand. They also said to never use the 200ma charge rate, which increased the likelihood of missed termination, that I should use 500ma. However, some posts here have me wondering if I should be using 1000ma. Is all this true of the BC-700?
> 
> I'm contemplating getting a BC-700 in addition now, for a 2nd charger. Is it as good as the BC-900? I saw some posts at Amazon suggesting that the difference is essentially that the BC-900 comes with batteries and C and D cell adaptors. I need neither.



I bought a BC-700 a few weeks back, along with a Maha C9000 and can't complain. I don't mind the lower 700 mA charging limit of the BC-700. It's a smaller unit and will pack easily enough when I go travel next month.

As far as charging rates and fans go, La Crosse doesn't mention a minimum charging rate, like Maha does, so I don't know what's really up? On a 2900/2700 mAh battery, like my Accupower 2900s and my Sanyo 2700s, that 700 mA charge rate is still going to be below .25C and certainly below Maha's recommended .3C.

I've charged at 200mA and didn't have any issues with the charger charging for a seemingly longer time, so that lower rate hasn't been an issue for me. At lower charging rates, batteries supposedly last longer. Still, the BC-700 will give you that 700mA rate and we might just be splitting hairs when it comes to the hi-cap HSD batteries like I mention above and not being at Maha's .3C minimum.

Chris


----------



## Muse (Mar 15, 2012)

I went ahead and ordered the BC-700, so now I'll have that and my 5 year old BC-900. I'm usually not in a hurry and my main concern is battery longevity. If that's not affected, of course I'd prefer a quicker charge. However, I don't want to risk missed termination, especially if that will affect the life of the battery, or worse, risk a meltdown of the charger. I have never used a rate higher than 500ma and don't anticipate doing so, so the choices are 200ma and 500ma (unless someone assures me that a higher rate has no negative implications). 

*Given these concerns, what is the best charge rate to use with AA and AAA eneloops in these two chargers?*


----------



## lwien (Mar 15, 2012)

I've been using the BC-700 with Eneloops for over a year now without EVER having a problem. 

When charging 2AA, I'll use 700ma. When charging 4AA, I'll drop it down to 500ma simply because the batts are spaced pretty close together and 500ma will generate less heat.
When charging 2AAA, I'll use 500ma. When charging 4AAA, I'll drop it down to 200ma for the same reason that I stated above.

NEVER had an issue with missed terminations or the batteries coming off the charger too warm.


----------

