# Rayovac 4.0 NIMH cells --what's up with them?



## kwkarth (Aug 25, 2009)

Hi folks. I've bee searching the forums looking for factual information about the New but now obsolete Rayovac 4.0 NiMh AA and AAA batteries.

I've found thread after thread where people seem to make assumptions about their chemistry, construction, and capacities.

To be fair, a great deal of the confusion comes from the misleading ad copy on their packaging and complete lack of information about them at Rayovac's web site.

I see enough differences documented between Rayovac Hybrids and these 4.0 to make me doubt they're identical, yet without evidence, most folks around here are assuming that they're identical to the Hybrids.

I'm looking for facts so that I can make an intelligent and informed decision regarding these battteries or Sanyo Eneloops. Has anyone studied this new battery?

Here's what I *think* I know about them so far...



I was looking around Rayovac's web site and found patent documents for their build in charge rate controller (IC3) I think they called it. It does seem to be in all three battery designs IC3, Hybrid, and 4.0 products.
I can find no mention at all of their supposedly patented Lithium Hydroxide coating on the anode which helps the cell have a lower self discharge rate.
This lithium hydroxide coating attribute seems to be confined to the 4.0 product so far as I know, yet the Hybrid product claims to hold a charge for a year, whereas the 4.0 product claims to hold 80% charge for six months. Could be just weasel words, but I wonder just the same.
Maybe the 4.0 product is less expensive to manufacture?
Rayovac Hybrid and 4.0 AA cells look identical to one another from the outside, and both are made in China.
The weight is within normal variance 27.5gm Hybrid, and 27.2gm to 27.6gm for the 4.0 cells
They seem to be able to put out a lot of current without getting hot., although I've not measured the extent of that capacity.
Running the TK40 on Turbo, the 4.0's stayed cool as a cucumber, while the light itself got very hot eventually. After using the 4.0's in the TK40 for about 2 weeks, folling this turbo test, I removed the cells from the light and their open circuit voltage was between 1.275V and 1.278V on all cells. Actually most measured 1.276V and 1.277V with one outlier at 1.275V and two at 1.278V
A freshly charged 4.0 cell measures 1.344V open circuit, a week off the charger, stored at room temperature.
I will start running some capacity tests tonight.
Currently, they can be had for 5 to 7 bux per 4 pack of AA's
With the price being so low for a LSD cell, compared to all the other LSD products on the market, added to the fact that this product no longer seems to be in the Rayovac catalog, it would seem that Rayovac is / had dumped these things cheap to get them off their inventory. Once they're gone, they're gone, and then we'll be having to pay higher prices again for other product, or... there's something wrong with them and that's why Rayovac is dumping them.
I find it hard to believe Rayovac would dump a defective product on the market, so it seems more likely that they may have infringed on an existing patent and had to drop the product to avoid law suits.
 

What factual information does anybody know about these things?


If they are any good, I hate to see other CPF'ers miss out on the bargin, but if they have some sort of inherent problem, we should warn people to stay away.


TIA!!


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## [email protected] (Aug 25, 2009)

kwkarth said:


> Hi folks. I've bee searching the forums looking for factual information about the New but now obsolete Rayovac 4.0 NiMh AA and AAA batteries.
> 
> I've found thread after thread where people seem to make assumptions about their chemistry, construction, and capacities.
> 
> ...



They're not obsolete. They are relabeled ROV hybrids (slightly crapper eneloops)


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## Marduke (Aug 25, 2009)

To summarize, Eneloops are still better cells...


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## kwkarth (Aug 25, 2009)

I am not taking issue with anything you guys are saying, just point me to somebody's test data.

Based upon what factual evidence, how do you know what you say is true?

[email protected], why do you say they're not obsoete? Are they still in Rayovac's catalog? Please show me.
Marduke, I take no issue with what you say, just show me why you say that.

Thanks guys!


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## Marduke (Aug 25, 2009)

Eneloops have lower internal resistance, higher voltage under load, lower selfdischarge, and have proven to be more robust than any other LSD cell when it comes to abuse and longevity. Data is scattered over dozens of threads and hundreds of inidividual user experiences.

Also keep in mind there are only a few factories that make LSD cells, and the majority are made by the same original three companies- Panisonic, Sanyo, and Yuasa-Delta. Most brands are just rebrands of one of those 3 companies.

While cheaper LSD cells may offer a good value for the money, and operate much better then regular NiMH cells, Eneloops remain the leader of the LSD pack.


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## davidt1 (Aug 25, 2009)

I have both Eneloops and ROV hybrids. The ROV hybrids worked fine for a few months. Then they had to be recharged every 2 weeks. I no longer use them. Now I use Eneloops only.


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## kwkarth (Aug 25, 2009)

Marduke said:


> Eneloops have lower internal resistance, higher voltage under load, lower selfdischarge, and have proven to be more robust than any other LSD cell when it comes to abuse and longevity. Data is scattered over dozens of threads and hundreds of inidividual user experiences.
> 
> Also keep in mind there are only a few factories that make LSD cells, and the majority are made by the same original three companies- Panisonic, Sanyo, and Yuasa-Delta. Most brands are just rebrands of one of those 3 companies.
> 
> While cheaper LSD cells may offer a good value for the money, and operate much better then regular NiMH cells, Eneloops remain the leader of the LSD pack.



Thanks for the info Marduke. I've read probably every thread I can find here about LSD cells, and I actually found a couple of mentions of the Rayovac 4.0 cells vs. Sanyo Eneloops. One thing I haven't found is a clear discussion about Rayovac 4.0 vs Rayovac Hybrid. I've never taken issue with Eneloop being top of the heap for most carefree and best performing LSD cell, but I'm not sure how up to date that info is kept. I'm also really curious about why Rayovac seems to have dropped this battery after only a year on the market. And where did the hybrid go? and why isn't the distribution of the Eneloop greater?... I'm beginning to think that LSD batteries work so well, that battery companies are beginning to worry that LSD's will take too much market share away from primary alkies. They make lots of scratch from selling alkalines.


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## kwkarth (Aug 25, 2009)

davidt1 said:


> I have both Eneloops and ROV hybrids. The ROV hybrids worked fine for a few months. Then they had to be recharged every 2 weeks. I no longer use them. Now I use Eneloops only.


What kind of charger did you use?


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## Marduke (Aug 25, 2009)

As stated previously, every indication thus far points towards 4.0's simply being relabled Hybrids.

I don't know if they were ever listed on the website, but their new packaged Hybrids still are. Perhaps the 4.0 packaging simply got canned for misleading advertising. 

But who cares? LSD are still available elsewhere for good prices. I recently got 6 packs of Duraloops for $4.50 per 4-pack.


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## davidt1 (Aug 25, 2009)

kwkarth said:


> What kind of charger did you use?



A small, quick charger. Charging time is between 2-6 hours. Both types of batteries go through the same charger.


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## Black Rose (Aug 25, 2009)

Marduke said:


> As stated previously, every indication thus far points towards 4.0's simply being relabled Hybrids.


That was verified by someone "in the know" late last year I believe.

It's in the original Rayovac 4.0 thread.


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## kwkarth (Aug 25, 2009)

Marduke said:


> As stated previously, every indication thus far points towards 4.0's simply being relabled Hybrids.
> 
> I don't know if they were ever listed on the website, but their new packaged Hybrids still are. Perhaps the 4.0 packaging simply got canned for misleading advertising.
> 
> But who cares? LSD are still available elsewhere for good prices. I recently got 6 packs of Duraloops for $4.50 per 4-pack.


Tell me about the Duraloops. I've never seen them in a store.


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## kwkarth (Aug 25, 2009)

davidt1 said:


> A small, quick charger. Charging time is between 2-6 hours. Both types of batteries go through the same charger.


So the eneloops are still going strong, but the hybrids no longer hold a charge?


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## 45/70 (Aug 25, 2009)

kwkarth said:


> ... I'm beginning to think that LSD batteries work so well, that battery companies are beginning to worry that LSD's will take too much market share away from primary alkies. They make lots of scratch from selling alkalines.



I've suggested this a couple times. I'm sure this has a whole lot to do with it.

Take a look at Energizer. What do they make? For the most part, alkaline batteries. Sanyo, who developed the first, and seemingly best LSD technology, is a vary broad ranged manufactuerer. They make all matter of electronic devices. From their view, it's not going to hurt them at all to come up with a superior rechargeable battery cell. Companies like Energizer, on the other hand, unless they come up with a better plan than they seem to have (like bringing to market crappy NiMH cells that don't really work, so folks go back to alkalines), is going to be SOL.

I've often wondered, as you have suggested, if there isn't some sort of legal battle going on behind the scenes between these two. And then, there are all the other players in the game as well.

Alkaline battery cells have been a multibillion dollar industry for years. Have you ever been in a public parking lot, and _*not*_ seen a couple alkaline cells somebody just dumped out of their MP3 player? I can't imagine change is going to be easy, and I'm sure the average Joe isn't going to be aware of what all is going on behind the scenes.

I might add, that I pretty much quit using alkaline's in the early 80's in favor of NiCd's. No, the runtimes weren't as good, but the performance was better. Cost really had little to do with it, although an added benefit. I've really never looked back since. With LSD technology, I think more people will come around, sooner or later. Again, it won't be easy. Some companies will go under, jobs will be lost and so on, but I don't really see it turning out any other way, in the end.

Dave


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## Marduke (Aug 25, 2009)

kwkarth said:


> Tell me about the Duraloops. I've never seen them in a store.



Duraloops is the slang name for Duracell branded Eneloops. There are also Durahybrids which are the Duracell branded cells of the same make as the ROV Hybrids. 

Both varieties (made in Japan and China, respectively) are much mure common B&M than Eneloops, which more often have to be purchased online.


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## kwkarth (Aug 25, 2009)

Marduke said:


> Duraloops is the slang name for Duracell branded Eneloops. There are also Durahybrids which are the Duracell branded cells of the same make as the ROV Hybrids.
> 
> Both varieties (made in Japan and China, respectively) are much mure common B&M than Eneloops, which more often have to be purchased online.


Gotchya. Thanks!


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## MorePower (Aug 25, 2009)

Marduke said:


> As stated previously, every indication thus far points towards 4.0's simply being relabled Hybrids.



Yep.



Marduke said:


> I don't know if they were ever listed on the website, but their new packaged Hybrids still are. Perhaps the 4.0 packaging simply got canned for misleading advertising.



4.0 was a product line (branding, if you will) created for a specific customer. After selling at that customer for a bit, distribution was actuallyexpanded. They were not "canned for misleading advertising."


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## davidt1 (Aug 25, 2009)

kwkarth said:


> So the eneloops are still going strong, but the hybrids no longer hold a charge?



That is correct.


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## kwkarth (Aug 25, 2009)

45/70 said:


> I've suggested this a couple times. I'm sure this has a whole lot to do with it.
> 
> Take a look at Energizer. What do they make? For the most part, alkaline batteries. Sanyo, who developed the first, and seemingly best LSD technology, is a vary broad ranged manufactuerer. They make all matter of electronic devices. From their view, it's not going to hurt them at all to come up with a superior rechargeable battery cell. Companies like Energizer, on the other hand, unless they come up with a better plan than they seem to have (like bringing to market crappy NiMH cells that don't really work, so folks go back to alkalines), is going to be SOL.
> 
> ...


Well said 45/70!

I've tried many times over the years to adopt any rechargeable technology to replace all of the primaries I use, and was an early adopter of every new technology that hit the streets. Nothing up till this point has really made sense for my useage patterns, until the advent of low self discharge cells. I tend to use devices sporadically and then not use that device for many weeks. I want it to work when I grab it. My gripe with primaries, besides cost factors, which really aren't a big issue for me, is the propensity for alkies to leak....I reeealy hate that! Then there's the issue of energy density. For a short while, I thought L91's were the answer, and to my chagrin, I found they're not the right answer for many things. 

It looks to me at this point like lsd's are the right (best available currently) solution for the broadest range of applications today. So now that I'm finally coming to that party, it looks almost like everybody else is starting to go home! This will be an interesting (and painful) battle to watch unfold.  I hope the consumer and the environment finally win one, instead of the big corporations.


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## kwkarth (Aug 25, 2009)

MorePower said:


> Yep.
> 
> 
> 
> 4.0 was a product line (branding, if you will) created for a specific customer. After selling at that customer for a bit, distribution was actuallyexpanded. They were not "canned for misleading advertising."



Interesting.
What customer? Why doesn't the product show up on Rayovac's site?


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## Marduke (Aug 25, 2009)

kwkarth said:


> Interesting.
> *What customer?* Why doesn't the product show up on Rayovac's site?



The uninformed customer who likely doesn't know what "precharged" or LSD even means.


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## Mr Happy (Aug 25, 2009)

Marduke said:


> kwkarth said:
> 
> 
> > Interesting.
> ...


Right, but I think MorePower meant a retail customer like one of the big box chains with large sales volumes...


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## Black Rose (Aug 25, 2009)

Here in Canuckistan, they (4.0) are only available at Wal-Mart (for $1.00 less than the Hybrids) whereas the Hybrids are available at another Canadian retailer.

I think they first showed up at Costco in the US.


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## Marduke (Aug 25, 2009)

Mr Happy said:


> Right, but I think MorePower meant a retail customer like one of the big box chains with large sales volumes...



I don't think so. I've seen them at at least half a dozen unrelated stores, from Costco to Walmart to even Disney World.


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## Mr Happy (Aug 25, 2009)

Marduke said:


> I don't think so. I've seen them at at least half a dozen unrelated stores, from Costco to Walmart to even Disney World.


Of course, because distribution was expanded as MorePower said. I'm pretty sure MorePower has inside knowledge on the subject...


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## Black Rose (Aug 25, 2009)

Marduke said:


> I don't think so. I've seen them at at least half a dozen unrelated stores, from Costco to Walmart to even Disney World.


 


MorePower said:


> 4.0 was a product line (branding, if you will) created for a specific customer. *After selling at that customer for a bit, distribution was actually expanded.*


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## Egsise (Aug 25, 2009)

davidt1 said:


> I have both Eneloops and ROV hybrids. The ROV hybrids worked fine for a few months. Then they had to be recharged every 2 weeks. I no longer use them. Now I use Eneloops only.


Thats interesting, I use ROV Hybrids in flashlights and in my digital camera.
The cells I use in my camera wait 4-8 weeks before they are being used and I have not noticed any signs of high self discharge.


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## Bullzeyebill (Aug 25, 2009)

I am seeing the Duracell LSD'S at Costco, and Target in my town. The Chinese made Duracell's at Costco, and the Japan made Duracells at Target, where I bought a four pack.

Bill


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## kwkarth (Aug 25, 2009)

Mr Happy said:


> Right, but I think MorePower meant a retail customer like one of the big box chains with large sales volumes...


That's what I assumed he meant, but there is certainly no indication of that on the packaging.


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## kwkarth (Aug 25, 2009)

Black Rose said:


> Here in Canuckistan, they (4.0) are only available at Wal-Mart (for $1.00 less than the Hybrids) whereas the Hybrids are available at another Canadian retailer.
> 
> I think they first showed up at Costco in the US.


Interesting, in our area, we have no Walmart (Walley's World) within 20 miles and 3 Costo's within 2 miles, including the largest Costco in the US, and I've never seen the Rayovac 4.0 in any Costco.


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## kwkarth (Aug 25, 2009)

Bullzeyebill said:


> I am seeing the Duracell LSD'S at Costco, and Target in my town. The Chinese made Duracell's at Costco, and the Japan made Duracells at Target, where I bought a four pack.
> 
> Bill


I'm going to have to check out Target around here to see what they carry.


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## Wyeast (Aug 25, 2009)

The ROV4.0's were actually pulled from Costco. I ran into like half a pallet of them once (towards the end) at my local Costco and tried to convince someone to pull them down so I could buy up a bunch. Eventually I was contacted by a supervisor or manager or something who said that they could no longer sell them, as they were being returned to manuf.

As far as I know, they were roughly equivalent to the ROV Hybrids (Chinese LSD's), but never saw any hard test data. I still have several that are still working in the regular cycle with the Eneloops & Duraloops.


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## lctorana (Aug 27, 2009)

I am very fond of the Varta "15 minute" cells. These disappeared from the market last year, and were sold off in the end very cheaply.

The actual 15 minute chargers, while they worked, were too hard on the cells, I'm guessing.

But what I'm wondering is, could the RayOVac 4.0 and the Varta 15 Minute be the same cell?

Because "4.0" might just mean "_able to be charged at 4C_".

Maybe. Just a thought.


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## kwkarth (Aug 27, 2009)

lctorana said:


> I am very fond of the Varta "15 minute" cells. These disappeared from the market last year, and were sold off in the end very cheaply.
> 
> The actual 15 minute chargers, while they worked, were too hard on the cells, I'm guessing.
> 
> ...



All of the 15minute cells I've seen have had a higher advertised capacity than the ROV4.0's, so probably not, however, ROV holds the patent on their NiMH cells having a built in recharging protection that's supposed to allow their batteries to be used with "any" charger. 

I've recharged 8 x ROV-4.0's twice in my 15 minute charger and then, this last time "tested" all 8 for capacity in the LaCrosse 9009. They all came out around 2100mAh, with the lowest being 2050mAh. 

What I've read says that the super high rate charger may reduce the total available number discharge-recharge cycles by a couple over the life of the battery. The convenience of completely recharging 8 x AA's in under an hour is worth it to me. 

So instead of 500 recharges, I get 498, big deal. I save over 3800 hours in recharge time. If I get 995 instead of 1000 recharges, then I save over 7600 hours of my time. Fair trade. That's a year's worth of time. Wow!


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## Marduke (Aug 27, 2009)

Routine charging at 4C will shorten life to less than 100 cycles, with worsening performance as you go.


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## MorePower (Aug 27, 2009)

lctorana said:


> I am very fond of the Varta "15 minute" cells. These disappeared from the market last year, and were sold off in the end very cheaply.
> 
> The actual 15 minute chargers, while they worked, were too hard on the cells, I'm guessing.
> 
> ...



The 15 minute cells are not the same as the 4.0 cells. 15 minute cells use Rayovac IC-3 technology, 4.0 cells are low self-discharge and do not use IC-3 tech.

Charging the 4.0 cells at 4C is not recommended.


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## kwkarth (Aug 27, 2009)

MorePower said:


> The 15 minute cells are not the same as the 4.0 cells. 15 minute cells use Rayovac IC-3 technology, 4.0 cells are low self-discharge and do not use IC-3 tech.


This is interesting. Where did you find that information?


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## kwkarth (Aug 27, 2009)

Marduke said:


> Routine charging at 4C will shorten life to less than 100 cycles, with worsening performance as you go.


Have you done this?


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## Marduke (Aug 27, 2009)

kwkarth said:


> Have you done this?



Silverfox did extensive testing at 4C.


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## kwkarth (Aug 27, 2009)

Marduke said:


> Silverfox did extensive testing at 4C.


With the ROV 4.0 batteries?


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## Mr Happy (Aug 27, 2009)

kwkarth said:


> This is interesting. Where did you find that information?


I'm sorry, but why are you being so distrustful of information being provided to you? You are a relative newcomer to a forum where people have spent years buying cells, testing cells, doing industry research, talking to manufacturers and distributors, and for that matter _being_ manufacturer representatives and distributors.

Perhaps you could spend a little time doing some research and reading up on the subject yourself?


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## Black Rose (Aug 27, 2009)

kwkarth said:


> With the ROV 4.0 batteries?


It doesn't matter what type of NiMh battery it is...they all take a beating with that level of charge rate and end up with a shortened life because of it.


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## MorePower (Aug 27, 2009)

MorePower said:


> The 15 minute cells are not the same as the 4.0 cells. 15 minute cells use Rayovac IC-3 technology, 4.0 cells are low self-discharge and do not use IC-3 tech.





kwkarth said:


> This is interesting. Where did you find that information?



Like Mr. Happy said, some of us on the forum are a lot closer to the industry and to manufacturers than you apparently realize.

Regarding IC-3 tech, Rayovac bought Varta, Varta shortly thereafter released 15 minute cells.

4.0 = Rayovac hybrid = Varta Ready2Use


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## kwkarth (Aug 27, 2009)

Mr Happy said:


> I'm sorry, but why are you being so distrustful of information being provided to you? You are a relative newcomer to a forum where people have spent years buying cells, testing cells, doing industry research, talking to manufacturers and distributors, and for that matter _being_ manufacturer representatives and distributors.
> 
> Perhaps you could spend a little time doing some research and reading up on the subject yourself?


Why are you being so confrontational and judgmental? Do you have a problem with inquisitive, eager to learn minds? In my short few years here, you seem to waste a great deal of time jumping to incorrect conclusions. I'm surprised at you. BTW, I've been around here longer than you. As far as me spending time "reading" up on a subject, I'm only asking questions for which I've only found conflicting or limited information.

For your information, when someone tells me something with no qualifiers, the first thing I want to know is where they got their information. Marduke kindly answered my question, citing Silverfox. I have read much of Silverfox's posting and have great respect for what he says. What he says is not merely repeating hearsay and innuendo, but actually based upon a lot of testing and experience.

Mr. Happy, if you want my respect, you will need to earn it. So far, you're not tracking very well. The next time you want to question my motives, send me a PM instead of disrupting the forum with your troll like behavior.


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## kwkarth (Aug 27, 2009)

Black Rose said:


> It doesn't matter what type of NiMh battery it is...they all take a beating with that level of charge rate and end up with a shortened life because of it.


I'm begining to see that pattern. Thanks!


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## kwkarth (Aug 27, 2009)

MorePower said:


> Like Mr. Happy said, some of us on the forum are a lot closer to the industry and to manufacturers than you apparently realize.
> 
> Regarding IC-3 tech, Rayovac bought Varta, Varta shortly thereafter released 15 minute cells.
> 
> 4.0 = Rayovac hybrid = Varta Ready2Use


I would love to know what industry affiliations are represented here.

My question about IC-3 has not been answered yet. I thought from reading ROV's web site, that the hybrids, (and by implication the 4.0) contained IC-3 technology. MorePower said they did not. I would like to see that information for myself because it conflicts with what I thought I read.
What's your take on this?


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## Bullzeyebill (Aug 27, 2009)

There is much info here on CPF and many of our members have studied dozens and sometimes hundreds of threads to gleam this info. They may not remember exactly where they learned this info. The best thing to do is to take their info and either learn from it, and or do some searching on CPF on your own, using some of the key words to access the info you want. You can also search the web to substantiate some of the info you are receiving here by fellow CPF'ers. CPF'ers are generally very helpful, but it is up to each of us to do our own researching if we doubt what we are hearing, or want more info to sutstantuate what you hear here.

Bill


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## Marduke (Aug 27, 2009)

But there is a big difference between asking why something is, and demanding proof for no particular reason other than distrust of the information. Much of the knowledge contained within CPF is the accumulation of years of study, and that knowledge is not easy to distill down for others to understand in a meaningful way. A full explanation would entail dozens if not hundreds of individual posts and tests, as well as accumulated self experience and observation of the group experience of others.

In short, you easily come off not as wanting more info, but chalanging the info presented, which will quickly drive off the "experts" you seek to learn from because they don't want bothered with taking the next 20 posts explaining a simple answer like "yes" or "no".


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## kwkarth (Aug 27, 2009)

Bullzeyebill said:


> There is much info here on CPF and many of our members have studied dozens and sometimes hundreds of threads to gleam this info. They may not remember exactly where they learned this info. The best thing to do is to take their info and either learn from it, and or do some searching on CPF on your own, using some of the key words to access the info you want. You can also search the web to substantiate some of the info you are receiving here by fellow CPF'ers. CPF'ers are generally very helpful, but it is up to each of us to do our own researching if we doubt what we are hearing, or want more info to sutstantuate what you hear here.
> 
> Bill


The word you want is glean, not gleam, and thank you Bill, I respect your suggestion. I've done, and will continue to do what you suggest. As I mentioned in a post above, the qusetions I ask are only the ones for which I've only been able to find insufficient or conflicting information.


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## kwkarth (Aug 27, 2009)

Marduke said:


> But there is a big difference between asking why something is, and demanding proof for no particular reason other than distrust of the information. Much of the knowledge contained within CPF is the accumulation of years of study, and that knowledge is not easy to distill down for others to understand in a meaningful way. A full explanation would entail dozens if not hundreds of individual posts and tests, as well as accumulated self experience and observation of the group experience of others.
> 
> In short, you easily come off not as wanting more info, but chalanging the info presented, which will quickly drive off the "experts" you seek to learn from because they don't want bothered with taking the next 20 posts explaining a simple answer like "yes" or "no".



Marduke,
How many text books would you accept if you found no citations about where the information contained therein came from?

How many articles in Wikipedia would you embrace if there were no citations attached? How many newspaper articles would you pay attention to if no sources were cited and the reporter were unknown to you?

What happened to the scientific mind around here? Let's be up front regarding from where we get our information, as we try to help one another. Is there something wrong with doing that?

Why should you assume anything I say should be given credence just because I'm on CPF? Doesn't the gate swing both ways? Out of respect for you, when I make a statement, I try and remember to give a reason / citation for why I said what I said. I'm just used to conducting myself in that manner. I'm really sorry if my inquisitiveness rubbed you the wrong way. I will try and temper my enthusiasm in the future, but know that in the future, it's always a good thing to know why you believe what you believe.

Ever been in a class where the instructor employs the Socratic method of teaching? Such methods are good for all of us. Keeps us sharp.

And by the way, I'm not demanding "proof" of anything, I just want to know, so that I can understand the whole picture better.
Thanks,


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## MorePower (Aug 27, 2009)

kwkarth said:


> I would love to know what industry affiliations are represented here.
> 
> My question about IC-3 has not been answered yet. * I thought from reading ROV's web site, that the hybrids, (and by implication the 4.0) contained IC-3 technology.* MorePower said they did not. I would like to see that information for myself because it conflicts with what I thought I read.
> What's your take on this?



If you can give me a link to the Rayovac website that implied Hybrid cells contain IC-3 technology, I'll see what I can do to get that misinformation fixed.


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## Marduke (Aug 27, 2009)

But CPF is not a classroom, it is an open forum. If the information given is correct, great. If it sounds fishy, someone will question it WITH REASON. If it is flat out wrong, someone will correct it with factual information. All posts are essentially peer reviewed, and the BS doesn't survive.


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## kwkarth (Aug 27, 2009)

MorePower said:


> If you can give me a link to the Rayovac website that implied Hybrid cells contain IC-3 technology, I'll see what I can do to get that misinformation fixed.


I'll see if I can dig that up again.
Thanx.
kevin


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## kwkarth (Aug 27, 2009)

Marduke said:


> But CPF is not a classroom, it is an open forum. If the information given is correct, great. If it sounds fishy, someone will question it WITH REASON. If it is flat out wrong, someone will correct it with factual information. All posts are essentially peer reviewed, and the BS doesn't survive.


My life is a classroom and I learn a great deal from CPF. I understand your point. Thanks Marduke. 

Can you amplify what you meant regarding questioning WITH REASON, since you seem to imply that I have no reason for my qustions.


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## Marduke (Aug 27, 2009)

If you feel something is incorrect, some aspect of the information made you feel that way. Is it "insider info" unlikely to be found here, does the math or physics not sit right but you don't have the knowledge to show it, or does it just not pass the common sense filter. 

Conversely, there are those who with no reason other than to be a pain (apparently) question EVERY satement just to force the issue or annoy the presenter. 

At some point you simply have to trust that the "experts" know what they are talking about, and have no reason to be deceptive.


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## kwkarth (Aug 27, 2009)

MorePower said:


> If you can give me a link to the Rayovac website that implied Hybrid cells contain IC-3 technology, I'll see what I can do to get that misinformation fixed.


I haven't found it yet, and am still looking, but I did find an interesting PDF that shows under ideal charge/discharge conditions, the best one could expect from the hybrid is less than 250 charge/discharge cycles, with near max performance. At 250 cycles, there is only 1600mAh capacity left, at 400 cycles there's only 1250mAh capacity. The first knee in the curve comes at about 250 cycles where capacity drops from 1900mAh to 1700mAh by 150 cycles. There is an almost linear decline in capacity from there out through 400 cycles. document name @ rayovac.com is "nm715_2100mah.pdf" So at least for ROV's I'll figure cost factors on a 250 cycle norm.


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## kwkarth (Aug 27, 2009)

Marduke said:


> If you feel something is incorrect, some aspect of the information made you feel that way. Is it "insider info" unlikely to be found here, does the math or physics not sit right but you don't have the knowledge to show it, or does it just not pass the common sense filter.
> 
> Conversely, there are those who with no reason other than to be a pain (apparently) question EVERY satement just to force the issue or annoy the presenter.
> 
> At some point you simply have to trust that the "experts" know what they are talking about, and have no reason to be deceptive.


Marduke, I do trust the experts to know what they're talking about. I didn't know that you were an "expert", though you may be, as you never gave any indication of being one. Please forgive me.

As I said earlier, I recognize Silverfox to be an expert and have never questioned the veracity of his measurements. I have NEVER questioned anything to "force" an issue or to "annoy" you. I'm sorry that you perceive my quest for knowledge that way. I hope you meet other inquisitive people in your life, because it will be good for you. With all your getting, get understanding.


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## MorePower (Aug 27, 2009)

kwkarth said:


> I haven't found it yet, and am still looking, but I did find an interesting PDF that shows underideal charge/discharge conditions, the best one could expect from the hybrid is less than 250 charge/discharge cycles, with near max performance. At 250 cycles, there is only 1600mAh capacity left, at 400 cycles there's only 1250mAh capacity. The first knee in the curve comes at about 250 cycles where capacity drops from 1900mAh to 1700mAh by 150 cycles. There is an almost linear decline in capacity from there out through 400 cycles. document name @ rayovac.com is "nm715_2100mah.pdf" So at least for ROV's I'll figure cost factors on a 250 cycle norm.




NM715 is the Rayovac part number for standard NiMH AA cells, not LSD NiMH AA cells (which are LD715), so the data you found doesn't necessarily apply to the Rayovac Hybrid cells.

I do not know if the LSD cells hold up better or worse to fast charging.

If you find the other link feel free to PM it to me, as this thread is already getting pretty far off the original topic of Rayovac 4.0 cells.


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## kwkarth (Aug 27, 2009)

MorePower said:


> NM715 is the Rayovac part number for standard NiMH AA cells, not LSD NiMH AA cells (which are LD715), so the data you found doesn't necessarily apply to the Rayovac Hybrid cells.
> 
> I do not know if the LSD cells hold up better or worse to fast charging.
> 
> If you find the other link feel free to PM it to me, as this thread is already getting pretty far off the original topic of Rayovac 4.0 cells.


Will do. Thanks very much for your help. I agree, both the warp and the weft threads of the fabric of our discussion have pretty much unraveled. :thinking:


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## Black Rose (Aug 27, 2009)

kwkarth said:


> document name @ rayovac.com is "nm715_2100mah.pdf" So at least for ROV's I'll figure cost factors on a 250 cycle norm.


That's not the Hybrid data sheet. 
NM715 is the part number for the regular 2100 mAh NiMh cells (as MorePower has pointed out).

The Rayovac Hybrid AA cells are part number LD715. 
The Rayovac 4.0 AA cells are part number RF715.


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## Bones (Aug 27, 2009)

kwkarth said:


> I haven't found it yet, and am still looking, but I did find an interesting PDF that shows under ideal charge/discharge conditions, the best one could expect from the hybrid is less than 250 charge/discharge cycles, with near max performance. At 250 cycles, there is only 1600mAh capacity left, at 400 cycles there's only 1250mAh capacity. The first knee in the curve comes at about 250 cycles where capacity drops from 1900mAh to 1700mAh by 150 cycles. There is an almost linear decline in capacity from there out through 400 cycles. document name @ rayovac.com is "nm715_2100mah.pdf" So at least for ROV's I'll figure cost factors on a 250 cycle norm.



The following was the only life cycle chart in the document you referenced kwkarth:







I believe it represents an 'accelerated' life cycle test, and should be considered in that context.

In this instance, the cell was subjected to a continuous series of 1C (2100mA) charges and discharges interspersed with rest periods of a mere 30 minutes for over 50 days and nights.

Incidentally, you're the first person I've seen label an accelerated life cycle test as 'ideal charge/discharge conditions'.


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## Mr Happy (Aug 27, 2009)

Bones said:


> I believe it represents an 'accelerated' life cycle test, and should be considered in that context.


In the same vein, -dV = 8 mV per cell is quite high for NiMH. A value in the range of 2 - 4 mV would be kinder.


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## Bones (Aug 27, 2009)

Mr Happy said:


> In the same vein, -dV = 8 mV per cell is quite high for NiMH. A value in the range of 2 - 4 mV would be kinder.



Very good point.

In another vein, did you notice that the capacity didn't fully peak until around the 50 cycle mark? It appears to be notated with a diamond.


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## Bones (Aug 27, 2009)

Mr Happy said:


> In the same vein, -dV = 8 mV per cell is quite high for NiMH. A value in the range of 2 - 4 mV would be kinder.



I was just comparing the Rayovac test with that for the Eneloop.

As badly as Rayovac flogged their cell, Sanyo flogged the Eneloop even worse:






The enloop was tested 25°C ambient instead of 20°C; an even higher -dV was utilized (10mV instead of 8); and it was only allowed a 20 minute rest period after charging and a 10 minute rest period after discharging.


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## lctorana (Aug 27, 2009)

I think the diamonds are indfividual data points, and the clearly visible one is just an outlier.

(Oh and thanks MorePower - that product code information is valuable.
I'll use it to try to locate detailed tech specs on my Varta 15min cells.
They remain as one of ony four types of AA cells I still use.)


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## Marduke (Aug 27, 2009)

Where did that Eneloop data come from? I've been looking for their detailed specifications.


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## Mr Happy (Aug 27, 2009)

Bones said:


> I was just comparing the Rayovac test with that for the Eneloop.


Oh, good catch. It does make for a good comparison though.


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## Bones (Aug 27, 2009)

Marduke said:


> Where did that Eneloop data come from? I've been looking for their detailed specifications.



It came from the Sanyo Europe website Marduke.

This post contains a summary and some links:

http://www.candlepowerforums.com ... post2785837
-


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## Marduke (Aug 27, 2009)

Bones said:


> It came from the Sanyo Europe website Marduke.
> 
> This post contains a summary and some links:
> 
> ...



It would be nice if all their websites had the same info.

Thanks for the link.


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## kwkarth (Aug 27, 2009)

Bones said:


> I was just comparing the Rayovac test with that for the Eneloop.
> 
> As badly as Rayovac flogged their cell, Sanyo flogged the Eneloop even worse:
> 
> ...


Sanyo used lower charge and discharge currents. My comments about life cycle had to do with the conditions being similar to my use of the super fast charger in that same context. thanks for the comparative graph and link.


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## kwkarth (Aug 27, 2009)

Mr Happy said:


> In the same vein, -dV = 8 mV per cell is quite high for NiMH. A value in the range of 2 - 4 mV would be kinder.


8mV delta trigger probably represents a worst case algorithm used in a brand xyz charger to ID cutoff point for charging. I see that Sanyo chose 10mV. Note that ROV discharged to 0.9V where Sanyo was kinder @ choosing 1.0V threshold.

So it's somewhat of a mixed bag. Which abuse is actually harder on a cell? Dicharge threshold? Charge end trigger level. Rate of charge/discharge? Rest period? Ambiant temperature. I think all of these parameters can be related to having an effect on the internal cell temperature.

In the final analysis it looks like the ROV exhibited better overall battery life, but that does not seem to jive with people's experience. Hmmm.


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## Marduke (Aug 27, 2009)

Eneloops were abused harder (as already stated)

They are THE premium cell for a reason, they perform the best under the worst conditions.


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## kwkarth (Aug 28, 2009)

Marduke said:


> Eneloops were abused harder (as already stated)
> 
> They are THE premium cell for a reason, they perform the best under the worst conditions.


Marduke, could you please educate me as to how you drew that conclusion from the two life cycle test graphs shown above, or are you drawing that conclusion from other data not referenced here in this thread?
Note: I'm not trying to annoy you, I'm merely too stupid to understand how you drew that conclusion from the two graphs presented.
Thanks,


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## Marduke (Aug 28, 2009)

kwkarth said:


> Marduke, could you please educate me as to how you drew that conclusion from the two life cycle test graphs shown above, or are you drawing that conclusion from other data not referenced here in this thread?
> Note: I'm not trying to annoy you, I'm merely too stupid to understand how you drew that conclusion from the two graphs presented.
> Thanks,



See post 64...


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## kwkarth (Aug 28, 2009)

Marduke said:


> See post 64...


See post 71, question still stands.


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## Bullzeyebill (Aug 28, 2009)

kwkarth said:


> Marduke, could you please educate me as to how you drew that conclusion from the two life cycle test graphs shown above, or are you drawing that conclusion from other data not referenced here in this thread?
> Note: I'm not trying to annoy you, I'm merely too stupid to understand how you drew that conclusion from the two graphs presented.
> Thanks,



If you do not agree with Marduke, I think it would best if you ignored his comments. Your rebuttal, particularly your last sentence, can be considered baiting, and your purpose is to make him look foolish. 

Your thread title seems to show that you are interested in learning something about Rayovac 4.0 NiMh cells. Good to ask questions, and not so good to antagonize fellow CPF'ers in the process. 

Bill


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## 45/70 (Aug 28, 2009)

Hummm.

I think part of the problem here involves how one perceives these two graphs. There is more than one way to come to more than one conclusion, if that makes any sense.

You can look at the big picture, concentrating on a specific quality, such as total capacity, number of cycles, or some other combination of the two you're concerned with.

Here's how I look at the graphs. I'm a perfromance minded individual when it comes to battery cells. I don't really pay any attention to the right side of these graphs. Who cares about a 2000-2100mAh cell when it only delivers 1600mAh, or less.

At this point, I look at the cells performance at the start of the test. The first 50 cycles or so defines the actual capabilities of each cell. Under the test conditions presented here, after the first few cycles, they are close in mAh performance with the 2100mAh Rayovac appearing to have a 30-40mAh lead over the 2000mAh eneloop . That's for all practical purposes the same, in my opinion.

Following the cells progress along the x axis (number of cycles), the next point of interest is the point at which the mAh starts to decline. For the Rayovac, I see the "knee" of the decline starts at about 125 cycles. For the eneloop the "knee" starts at, or slightly before 200 cycles.

As I said before, I have a performance minded view of battery performance. If you were more interested in powering remote controls or wall clocks with your cells, you would very likely not interpret these graphs in the same way I do. What I see though, is the eneloop having close to a 60% advantage over the Rayovac during it's "working" life, or number of cycles that it is closest to it's designed mAh capacity.

I hope this helps at least a few of you understand that these graphs can be interpreted in more than one way. "Beauty is in the eye of the beholder".

Dave


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## Egsise (Aug 28, 2009)

I'll spit in the soup too...does the internal resistance grow on Hybrid or Eneloop cells?
Theres no point having 500 charge cycle life if the internal resistance is so high that it cant give 2A to my 1xAA flashlight.


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## kwkarth (Aug 28, 2009)

Bullzeyebill said:


> If you do not agree with Marduke, I think it would best if you ignored his comments. Your rebuttal, particularly your last sentence, can be considered baiting, and your purpose is to make him look foolish.
> 
> Your thread title seems to show that you are interested in learning something about Rayovac 4.0 NiMh cells. Good to ask questions, and not so good to antagonize fellow CPF'ers in the process.
> 
> Bill


Stop it! What is wrong with you people? I'm asking a question! I do agree with him, but I want to know more than hearsay, I want to learn WHY things are the way they are. Can't you guys get that through your heads?

The two graphs do not back up what everyone's experience is, or if they do, I don't completely understand the mechanism at work here. I'm not looking for a quick cut and run answer, I'm looking to learn something. There has to be at least one other person somewhere on this board who understands this concept. Did you read what I wrote in the post I referred Marduke to? Here it is again, in case you missed it the first time;


> 8mV delta trigger probably represents a worst case algorithm used in a brand xyz charger to ID cutoff point for charging. I see that Sanyo chose 10mV. Note that ROV discharged to 0.9V where Sanyo was kinder @ choosing 1.0V threshold.
> 
> So it's somewhat of a mixed bag. Which abuse is actually harder on a cell? Dicharge threshold? Charge end trigger level. Rate of charge/discharge? Rest period? Ambiant temperature. I think all of these parameters can be related to having an effect on the internal cell temperature.
> 
> In the final analysis it looks like the ROV exhibited better overall battery life, but that does not seem to jive with people's experience. Hmmm.


 So what factors are most important to battery life? Why do these two graphs seemingly conflict with everybody's experience? Or am I reading them wrong? If you don't know or don't care, then you can ignore the question, but to berate me for asking questions? This is amazing. I've never seen such an environment so hostile to learning. Get the chips off your shoulders people! Nobody's out to get you. I'm just trying to learn.


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## kwkarth (Aug 28, 2009)

45/70 said:


> Hummm.
> 
> I think part of the problem here involves how one perceives these two graphs. There is more than one way to come to more than one conclusion, if that makes any sense.
> 
> ...


Dave, This makes a lot of sense, thanks for taking the time to explain your thought process. I agree with that rationale. So it looks like the eneloop performs well @ around 1800mAh to about 200 cycles, whereas the ROV is pushing about the same 1800-1900mAh, but for only about 125 cycles. That makes a lot of sense, and clearly the eneloop is more desirable in that scenario. Since the test conditions are not identical, do you know which of the parameters that differ are more or less responsible for being harder or easier on battery life regardless of brand? In other words, If I'm going to abuse my batteries, which abuse will shorten their useful life the most? 

8mV delta trigger probably represents a worst case algorithm (according to ROV) used in a brand xyz charger to ID cutoff point for charging. I see that Sanyo chose 10mV, which is even harder on the cell being tested. Note that ROV discharged to 0.9V where Sanyo was kinder @ choosing 1.0V threshold. So, we've got apples and oranges.

Dicharge threshold? Charge end trigger level. Rate of charge/discharge? Rest period? Ambient temperature. I think all of these parameters can be related to having an effect on the internal cell temperature, no? Which of these abuses cause the greatest rise in internal temperature? Is the temperature always a function of IR losses or is there some chemical action generating heat as well?

Thanks man!


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## kwkarth (Aug 28, 2009)

Egsise said:


> I'll spit in the soup too...does the internal resistance grow on Hybrid or Eneloop cells?
> Theres no point having 500 charge cycle life if the internal resistance is so high that it cant give 2A to my 1xAA flashlight.


Good question. I would imagine that as internal resistance grows, the voltage produced would sag even more from IR loss, as would internal heat generated in the cell. Maybe that's the primary cause for the voltage sag beyond the "useful" life cycle?


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## Marduke (Aug 28, 2009)

Your question was already answered before you asked, in post 64. What makes it worse is already summarized...

Graphs don't back up people's experiences? They most certainly do, the Eneloops outperformed the competition when subjected to even harsher conditions...


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## kwkarth (Aug 28, 2009)

Marduke said:


> Your question was already answered before you asked, in post 64. What makes it worse is already summarized...
> 
> Graphs don't back up people's experiences? They most certainly do, the Eneloops outperformed the competition when subjected to even harsher conditions...


I'm sorry Marduke, it was not answered in post 64, but that's ok. Don't worry about it any more. Thanks for your help.


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## Marduke (Aug 28, 2009)

Well, you asked what made it worse, and he spells it out. No matter how many times you ask, that answer is not any different.


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## kwkarth (Aug 28, 2009)

Marduke said:


> Well, you asked what made it worse, and he spells it out. No matter how many times you ask, that answer is not any different.


It's ok, not to worry. You and I are just on different wavelengths. Thanks


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## VidPro (Aug 28, 2009)

*Which of these abuses cause the greatest rise in internal temperature?* and subsequent damage, probably the overcharge itself at termination.

both discharge levels are well within safe parameters, along with the temperatures being quite "normal". if you want to do the most damage, "Reverse charge", which they rarely ever show that sort of damage in thier testing, and the overcharge on V-drop termination, where the most ammount of heat occurs, and the most harsh it would be on the elements at the time.

the enloop testing IS tougher specs, but heck it is all based on the equiptment they use to do the test, and anybody just Hand drawing the graph when they are tired of testing :devil:

plus "subject to change" comes up, everything always has that lawyer speak in it somewhere , when they transfer the manufacturing process to the "other" plant. we did NOT buy the battery they tested , obviously , we just got one that may be very similar.

the cool thing is they can BS all they want, and show us spec sheets and test till they and thier corporate bean counters, and lab techs, and marketing gurus are blue in the face. But the consumer is still going to be testing this stuff in real situations on daily basis, and will know the truth. and the truth will set you free


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## Egsise (Aug 28, 2009)

Marduke said:


> Eneloops were abused harder (as already stated)
> 
> They are THE premium cell for a reason, they perform the best under the worst conditions.


I am not sure about that, has anyone tested hybrid vs eneloop in -20ºC(-4ºF)?
There is a this type of test going on with hybrid and eneloop AAA cells, and because the tester got very surprising results I'm going to do similar test with hybrid and eneloop AA cells.
Just to compare results between hybrid and eneloop AA and AAA cells.

If someone already has this kind of "worst condition" test results please let me know.


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## MorePower (Aug 28, 2009)

Marduke said:


> Well, you asked what made it worse, and he spells it out. No matter how many times you ask, that answer is not any different.



I'm a bit confused as well as to what made it worse, I must admit.

10mV dV is worse than 8mV dV, but has anyone quantified how much worse?
0.9V cutoff is worse than 1.0V cutoff, but again, how much of a difference did it make?
Shorter vs longer rest periods may make a difference, but was it really all that significant? Also Rayovac had no rest period between the end of the discharge and beginning of the charge cycle, so that's another unknown.
Both cells were charged at 1C, but 1C in the Rayovac test was 5% higher due to the higher cell capacity, so how did that affect things?

Perhaps most important to the discussion at hand is that *the Rayovac test data isn't for 4.0 / Hybrid cells, it's for standard NiMH AA cells* (tested nearly 2 years ago, no less).

*Marduke:* _"Graphs don't back up people's experiences? They most certainly do, the Eneloops outperformed the competition when subjected to even harsher conditions..." _ (sorry I didn't use the quote thingy, I'm not too good with the multi-quote feature)

As pointed out, "t_he competition_" wasn't... it was standard NiMH rather than LSD NiMH.

To say one test is worse for a cell than the other, without running the same brand of cells under both regimes, can not be stated with certainty.

To say the Eneloop is better than the 4.0 cells for cycle life, based on the 2 testing graphs presented, is impossible, especially because the Rayovac data presented isn't for the 4.0 / Hybrid cells.


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## VidPro (Aug 28, 2009)

lithium hydroxide being used in battery manufacture doesnt seem to be exclusive to ray-o-vac
http://74.125.155.132/search?q=cache:C41LLHSpHU0J:www.professional.duracell.com/safety_data/datasheets/pdf/Duracell%2520Nickel%2520Metal%2520Hydride%2520LSD%2520Rechargeable%2520Batteries%2520(EU%2520MSDS).pdf+%22Lithium+Hydroxide%22+nimh&cd=19&hl=en&ct=clnk&gl=us&lr=lang_en
there is durasell listing thiers for thier LSD, in the safety datasheet. i am not even sure its use is limited to LSD, as there is all sorts of "ways" they toss in various things to test how it reacts, to try and "fix" all sorts of caveats of the chemical reactions and interactions.

of course as we know, some durasell batteries are supposed to be ray-o-vac hybrids rebranded, putting that logic into its own loop 

so cross sanyo patent using the same stuff
http://74.125.155.132/search?q=cach...droxide"&cd=14&hl=en&ct=clnk&gl=us&lr=lang_en

and then an analisis of the ramifications of using it 
http://74.125.155.132/search?q=cach...droxide"&cd=13&hl=en&ct=clnk&gl=us&lr=lang_en

and of course about then my cell swells up and my head blows up, and then i realise that i dont work in a lab, i just use the freaking batteries, so what am i doing trying to figure out is thier use of a chemical is better , or who has more laywers or ways of recombining chemicals to avoid eachothers patents .

but i did notice, that while they are all patent warring eachother, they are all basically doing the same things, so we can be reasonable assured that they didnt get any alien technology from area 51 , and nothing is going to change that much untill that ONE person who actually discovers and invents things , sets them on a completly different course


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## kwkarth (Aug 28, 2009)

VidPro said:


> *Which of these abuses cause the greatest rise in internal temperature?* and subsequent damage, probably the overcharge itself at termination.
> 
> both discharge levels are well within safe parameters, along with the temperatures being quite "normal". if you want to do the most damage, "Reverse charge", which they rarely ever show that sort of damage in thier testing, and the overcharge on V-drop termination, where the most ammount of heat occurs, and the most harsh it would be on the elements at the time.
> 
> ...


Wow! This is great stuff. So this means that the charger used is of utmost importance, along with making sure you never over discharge a battery pack in use, as in TK40 AA's, right? What commercially available charger do you consider best from this perspective? I'm kinda thinking at this point that about a 2A charge rate (for LSD AA's) is good providing that temperatures are monitored. Does that make sense, or am I off base?

Thanks!


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## kwkarth (Aug 28, 2009)

MorePower said:


> I'm a bit confused as well as to what made it worse, I must admit.
> 
> 10mV dV is worse than 8mV dV, but has anyone quantified how much worse?
> 0.9V cutoff is worse than 1.0V cutoff, but again, how much of a difference did it make?
> ...



Well said. I'm still having real trouble finding anything at all specifically related to the 4.0 branded cells, but I also have not yet been able to find a similar pdf specifically showing test data for the ROV hybrid. Likewise there is a MSDS posted for the ROV "NIMH," but NOTHING I can find specifically for Hybrid or 4.0 cells. They seem to publish partial MSDS data for all of their general chemistries, but nothing more specific than that, leading me to believe the chemistry must be identical in all of their NiMH products. So internal construction geometry must be the only differentiator between their NiMH products.


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## VidPro (Aug 28, 2009)

kwkarth said:


> Wow! This is great stuff. So this means that the charger used is of utmost importance, along with making sure you never over discharge a battery pack in use, as in TK40 AA's, right? What commercially available charger do you consider best from this perspective? I'm kinda thinking at this point that about a 2A charge rate (for LSD AA's) is good providing that temperatures are monitored. Does that make sense, or am I off base?
> 
> Thanks!


 
the charger that prematurly terminates , of course, leaving your batteries not fully charged, but slow topping after that would come in really handy.
the maha chargers are now applying (more often) a voltage peaking termination or slowdown. you can also hear people say "batteries are cooler on so and so" often referring to the exact same charger that also doesnt charge them all the way up 

also the charger (and battery) that has all the cells at the same capacity level would come in handy so one is not dead before the others finish when used in series.

the charger used is ALWAYS of utmost importance, but i kinda doubt that we can all afford $10,000 camden chargers :mecry:, so somewhere in there must be a balance 

if the chemicals get "set up" into different "formations" depending on speed of charge, those same formations should be best for the discharge. so if you can fast charge AND properly slow down, and not heat or gas or "burn" the chemicals, or something like that, all to complex.
1C fine, but just remember that when 90% of the chemicals are converted over to thier charged state, 1C isnt referring to all the chemicals there anymore, because most of them wont Budge anymore. so i think it is logical to charge at about the rate your intending to discharge , within reason. concidering its speced abilities.
it is not logical to charge the last 5% of the chemicals at the same rate you charged the first 95% though is it.
you understand? cause i dont.

Pulse charging (which many digital chargers do by default) can slam the chemicals back into thier charged states, then pausing to allow heat to escape.
so with that you get the best of both worlds, if you have a 2C charger that pulses, it SEEMS like you would still get fast form, and the heat can still escape, besot of both worlds.


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## kwkarth (Aug 28, 2009)

VidPro said:


> lithium hydroxide being used in battery manufacture doesnt seem to be exclusive to ray-o-vac
> http://74.125.155.132/search?q=cache:C41LLHSpHU0J:www.professional.duracell.com/safety_data/datasheets/pdf/Duracell%2520Nickel%2520Metal%2520Hydride%2520LSD%2520Rechargeable%2520Batteries%2520(EU%2520MSDS).pdf+%22Lithium+Hydroxide%22+nimh&cd=19&hl=en&ct=clnk&gl=us&lr=lang_en
> there is durasell listing thiers for thier LSD, in the safety datasheet. i am not even sure its use is limited to LSD, as there is all sorts of "ways" they toss in various things to test how it reacts, to try and "fix" all sorts of caveats of the chemical reactions and interactions.
> 
> ...



LOL! Right you are! I like your spelling of Duracell/Durasell, very apt!

Yes, I also ran across an MSDS for a rechargeable Alkaline in which lithiun hydroxide was listed as a minor component.


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## kwkarth (Aug 28, 2009)

VidPro said:


> the charger that prematurly terminates , of course, leaving your batteries not fully charged, but slow topping after that would come in really handy.
> the maha chargers are now applying (more often) a voltage peaking termination or slowdown. you can also hear people say "batteries are cooler on so and so" often referring to the exact same charger that also doesnt charge them all the way up
> 
> the charger used is ALWAYS of utmost importance, but i kinda doubt that we can all affor 10,000 camden chargers :mecry:, so somewhere in there must be a balance


 Let's hope! 


> if the chemicals get "set up" into different "formations" depending on speed of charge, those same formations should be best for the discharge. so if you can fast charge AND properly slow down, and not heat or gas or "burn" the chemicals, or something like that, all to complex.
> 1C fine, but just remember that when 90% of the chemicals are converted over to thier charged state, 1C isnt referring to all the chemicals there anymore, because most of them wont Budge anymore.
> you understand? cause i dont.


Well, I think I understand the concepts as you explained them, but I must admit, I don't understand the nuances of the chemistry.
Seems like one has to approach the problem of best recharge algorithm somewhat heuristically, based upon what we know to be true about "typical" NiMH charge profiles. I would think charge level would be somewhat measureable based upon cell voltage level, and at the right points, one could lower the charge current appropriately. So the charge curve would look something like an inverse log curve. Charge current would be very steep at first and remain so, with a slight decline as charge level comes up, then as cell nears "full" state, current would eventually taper to a very low trickle. Obviously a very shallow charge rate at this point would make it exceedingly difficult to detect the delta trigger.


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## VidPro (Aug 28, 2009)

right , the problem with that being, they like to push the cell into the V-Drop, or "overcharge state" as i call it so thier little computer can SEE that the battery is fully charged. because the little microcontroller can read that the voltage is beginning to drop.
so they like to pulverise the cell so they can get this V-drop indicator, so thier charger can be "smart". so that means they have to reach the full charge point fast enough to put the cell into the "overcharge state" where it v-drops.
then they still have to top, because eveything wasnt nessisarily finished when it overheated or gassed or whatever happens that makes it freak like that. 

As a side note, they couldnt even make a battery that DIDNT v-drop anymore  without insisting on the user using a different charger.

if you charge at say .1c the vdrop does not occur sometimes EVER, or occurs so slowly that the microcontrollers cant see it and compare it with a previous reading.

maha went and messed that all up, by putting in more indicators, than just the v-drop itself on some of thier chargers.

none of the stuff uses temperature yet directally, to terminate, except as an emergency sort of thing. problem with that being temperatures in the charging area itself changing, and they would need more direct temperature connection, like some of the pro temp probes have, and some sort of fallable alogrythm for the temp increase too. (excepting 15min chargers that might use that method because it would be so obvious on those)


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## 45/70 (Aug 28, 2009)

kwkarth said:


> Since the test conditions are not identical, do you know which of the parameters that differ are more or less responsible for being harder or easier on battery life regardless of brand?



Well Kevin, since you asked 

First let me say that both manufacturers have put these cells through an abnormally rough test. That was their purpose, to "flog" them, as Bones said, and show the results.

So anyway, my own thoughts on the test conditions.

*Discharge threshold*.

If you've ever watched a cell discharge on something like a CBA (II) as I have, you would notice that once a cell gets down to 1.0 Volt (actually, higher), they drop out pretty fast. In my opinion, there's little difference between stopping at 0.9 Volt or 1.0 Volt for this type of test. But in absolute terms, 0.9 Volt would be harsher. Again though, I doubt it really makes much difference.

*-dV trigger*.

Whether it's 8mV or 10mV, it's really high. Any decent charger will have a -dV of 5mV or less, but yes, 10mV is going to be harsher on the cell than 8mV.

*Rate of charge and discharge*.

Manufacturers are going to use a standard for these rates, in this case, 1C for both. At least as related to graphs, such as have been provided, the charge and discharge rates are proportional to each cell.

One thing of note here, if you increase the rates, the "knee" will move to the left on the x axis, and if you decrease the rates the "knee" will move to the right on the x axis. Also, at some point of increased discharge, the bottom will fall out rather abruptly. The Hotwire guys are more than familiar with this. 

I don't see a 100mA difference in rates making much difference here.

*Rest period*.

Obviously, 30 minutes gives the cell more time to recuperate than 20 minutes. Still, I don't see this difference as having much of an effect either. It's not a very long rest period.

*Ambient temperature*.

This I would view as the most likely difference in the tests to affect the cells performance. Temperature is a major player on cell performance. Generally, cells can deliver higher current when hot, at the expense of less delivered capacity. The reverse is also true to some extent, less current is available, but also less capacity as well, under cold conditions.

I hate to say it again, but really, 5 degrees C probably isn't going to make a whole lot of difference, in my opinion.

I'm going to stop here. The conditions of the two tests to me, although not exactly the same, are close enough not to affect, in any significant way, the internal temps of the cells etc., for comparison. If anything, I'd have to say the Rayovac had it easier, but not enough to really matter.

Dave

PS: I see this thread has moved on quite a bit since I started composing my post. Busy day here. I'll float it anyway.


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## VidPro (Aug 28, 2009)

45/70 said:


> PS: I see this thread has moved on quite a bit since I started composing my post. Busy day here. I'll float it anyway.


 
i really liked your graph/test analisis in post #77 , it put the graphs into perspective well.


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## MorePower (Aug 28, 2009)

VidPro said:


> lithium hydroxide being used in battery manufacture doesnt seem to be exclusive to ray-o-vac
> http://74.125.155.132/search?q=cache:C41LLHSpHU0J:www.professional.duracell.com/safety_data/datasheets/pdf/Duracell%2520Nickel%2520Metal%2520Hydride%2520LSD%2520Rechargeable%2520Batteries%2520(EU%2520MSDS).pdf+%22Lithium+Hydroxide%22+nimh&cd=19&hl=en&ct=clnk&gl=us&lr=lang_en
> there is durasell listing thiers for thier LSD, in the safety datasheet. i am not even sure its use is limited to LSD, as there is all sorts of "ways" they toss in various things to test how it reacts, to try and "fix" all sorts of caveats of the chemical reactions and interactions.
> 
> ...



Your third link ("ramifications of using it") refers to lithium ion cells, not NiMH cells. You can tell because it talks about non-aqueous electrolyte and a graphite negative electrode.


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## kwkarth (Aug 28, 2009)

45/70 said:


> Well Kevin, since you asked
> 
> First let me say that both manufacturers have put these cells through an abnormally rough test. That was their purpose, to "flog" them, as Bones said, and show the results.
> 
> ...


Thanks Dave,
I had a suspicion that the differences were not that drastically different, but I really didn't know for sure in the grand scheme of all things NiMH. Good info, thank you!


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## VidPro (Aug 28, 2009)

MorePower said:


> Your third link ("ramifications of using it") refers to lithium ion cells, not NiMH cells. You can tell because it talks about non-aqueous electrolyte and a graphite negative electrode.


 
cool, i figured i might mess that up, or even find something that doesnt even exist yet , except in a pitri dish somehwere.
pure overload of data, but it was interesting how they still havent found the "perfect" seperator, or perfect anything really.
looks like they have long ways to go, and many ways to get there.


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## 45/70 (Aug 28, 2009)

VidPro said:


> i really liked your graph/test analisis in post #77 , it put the graphs into perspective well.



Thanks Vid. I've always liked graphical representations. Maybe that's why I can "see" them better. 

To return the compliment, I recognize you as one of the folks on these forums that _*really uses*_ batteries, and I always consider your comments very informative. :thumbsup:

Dave


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## VidPro (Aug 28, 2009)

i thought this was interesting too, and applies to many chemestries

*"The gas generated inside the cell possibly remains between the positive and the negative electrodes to the detriment of the opposing condition thereof, resulting in a decrease in cell capacity. "*
(probably didnt they LOOK) :twothumbs

this is the thing i always wonder about. they are talking about CO2 in this instance (and a specific chemistry), and in another discussion, by a forum member who knew chemistry, they discussed oxygen formation on overcharge.
and in Lead acid gell cells overcharged it leaves bubbles of probably oxygen and hydrogen, that totally ruins gell cells.

then they say "pressure" rises in ni-?? cells when they get to the overcharged area, you can even caliper measure older cells, or cells that have been severly overcharged, and they are bigger.

We have these tightly rolled cells, and the "resistance" stuff is all about how well "connected" everything is. with gasses seperating connections to, or floating around in what little electrolytes are there. add to that Oxygenated metals go from conductors to insulators, it seems like a no brainer.

then they talk about the stuff (like seperator) that gets broken down with the electrolytes, that give off gasses.
we all know that Any bad alkaline seems to be pushing outward a bit, bulging, stuff departing the containment, the liquids didnt grow, the solids didnt enlarge, it got airated. we all have seen the "puffy" li-poly, and i have seen the "spongy" li-poly.

so that HAS to be the answer to the elusive missing 300 cycles.
while thier tests are using standard type of charging methods as used by crappy smart chargers, i would swear we can do better than that test even  
Its just a matter of re-thinking constant current :sick2: and Beano!


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## Turbo DV8 (Aug 28, 2009)

> Originally Posted by *Bullzeyebill*
> 
> _There is much info here on CPF and many of our members have studied dozens and sometimes hundreds of threads to gleam this info. _


 



kwkarth said:


> The word you want is glean, not gleam, and thank you Bill ... the qusetions I ask are only the ones for which I've only been able to find insufficient or conflicting information.


 
kwkarth, the word you want is "questions", not "qusetions." There's a word for people with your attitude ... rhymes with "trick," and people who use it here might get a few days off.


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## kwkarth (Aug 28, 2009)

Turbo DV8 said:


> kwkarth, the word you want is "questions", not "qusetions." There's a word for people with your attitude ... rhymes with "trick," and people who use it here might get a few days off.


Good, positive contribution, thanks for the unprovoked attack. I guess I need to get my spell checker checked!


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## kwkarth (Aug 29, 2009)

VidPro said:


> i thought this was interesting too, and applies to many chemestries
> 
> *"The gas generated inside the cell possibly remains between the positive and the negative electrodes to the detriment of the opposing condition thereof, resulting in a decrease in cell capacity. "*
> (probably didnt they LOOK) :twothumbs
> ...


Isn't dendrite growth also a factor in shortened cell life, or is that not a factor in NiMh chemistry? I wonder if gas migration through the separators to the next layer of "plates" contributes to dendrite growth?


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## VidPro (Aug 29, 2009)

i dont know enough about the crystal stuff, and dendrites.
these gases go back and forth 100+ times 200 times, then it starts going badly. its like a warrenty :thinking: if the light overcharge at each end of charge keeps damaging it, then is there a certian ammount of buffer for the damage that runs out?

tom understands that stuff. i prioritise on things that visually and physically are in my face. i think that the communications about it are overly complex, when probably past the technobabble its more like potholes and cracks and rocks poking up through the ashfault, and plastic cracking in the sun, and salt flats drying out. <--- something that is already understandable.


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## kwkarth (Aug 29, 2009)

VidPro said:


> i dont know enough about the crystal stuff, and dendrites.
> these gases go back and forth 100+ times 200 times, then it starts going badly. its like a warrenty :thinking: if the light overcharge at each end of charge keeps damaging it, then is there a certian ammount of buffer for the damage that runs out?
> 
> tom understands that stuff. i prioritise on things that visually and physically are in my face. i think that the communications about it are overly complex, when probably past the technobabble its more like potholes and cracks and rocks poking up through the ashfault, and plastic cracking in the sun, and salt flats drying out. <--- something that is already understandable.


You're probably right. Cheers! Thanks for helping me learn more, I truly appreciate it.


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