6,560 FLASH POPS LATER: The Results of "AA" Rechargeable Battery Tests

SYS wrote in post #7716394
TEST #6:

“THE BEST ‘LOW SELF-DISCHARGE’ VS. THE BEST ‘PERFORMING’ BATTERY”

NOTE: The "Best Low Self-Discharge Battery" was determined by the combined results of the 1) “Ready to Use” and 2) “Shelf Life” (low self-discharge indicators) tests. The "Best Performing Battery" was determined by the combined results of the 3) “Camera Flash Pops,” 4) “Flash Recycle Time,” and 5) “Flashlight” (performance indicators) tests.


ENELOOP VS. POWEREX


ONE WEEK AFTER FULL CHARGE:

4 Sanyo eneloop – 2000mAh:

1st 5 Pop on Average Recycle Time: 4 @ 100% (4:05sec)
After 100 pops: 4 @ 80% (4:75sec)
After 200 pops: 4 @ 80% (4:89sec)
After 300 pops: 3 @ 80%, 1 @ 60% (5:24sec)
After 400 pops: 4 @ 60% (6:28sec)
After 450 pops: 4 @ 20% (13:12sec)
After 460 pops: 4 @ 20% (39:10sec)

4 MAHA Powerex – 2700mAh:

1st 5 Pop on Average Recycle Time: 4 @ 100% (4:12sec)
After 100 pops: 4 @ 80% (4:82sec)
After 200 pops: 4 @ 80% (4:96sec)
After 300 pops: 4 @ 80% (5:03sec)
After 400 pops: 4 @ 60% (5:69sec)
After 500 pops: 4 @ 40% (7:48sec)


THREE WEEKS AFTER FULL CHARGE:

4 Sanyo eneloop – 2000mAh:

1st 5 Pop on Average Recycle Time: 4 @ 100% (4.43sec)
After 100 pops: 4 @ 80% (4:93sec)
After 200 pops: 4 @ 80% (4:96sec)
After 300 pops: 4 @ 60% (5:58sec)
After 400 pops: 4 @ 40% (7:26sec)
After 450 pops: 4 @ 20% (17:39sec)
After 460 pops: 4 @ 20% (36:39sec)

4 MAHA Powerex – 2700mAh:

1st 5 Pop on Average Recycle Time: 4 @ 100% (4:73sec)
After 100 pops: 4 @ 80% (5:23sec)
After 200 pops: 4 @ 80% (5:35sec)
After 300 pops: 4 @ 80% (5:60sec)
After 400 pops: 4 @ 60% (5:73sec)
After 500 pops: 4 @ 40% (7:40sec)

WINNER IN BOTH TESTS: MAHA POWEREX 2700mAh

NOTE II: ENELOOP VS. IMEDION (POWEREX)

Among all the "low self-discharge" claiming batteries tested, these two in particular deserve some scrutiny. The problem, as already noted in the methodological "Limitations" section above, is that we don't know how long these new battery packages have been sitting around, and under what conditions, in the warehouses and on store shelves prior to being opened and tested. We don't have access to their manufacturing dates. So how do we interpret the test results, such as 16 eneloops (8 from Amazon.com and 8 from ThomasDistribution.com​) all registering at 100% capacity upon opening, and 8 Powerex Imedions (from ThomasDistribution.com​) all registering at 80% opening? It is possible that 8 Imedions were sitting around the warehouse 6 months or so longer than those 16 eneloops.

But suppose that eneloops are indeed superior to Imedions in the category of "low self-discharge" contest between the two (personally, this is what I "suspect")? After all, other brands with the same "low self-discharge" claims tested -- Duracell DX1500, Rayovac Hybrid, Kodak -- all failed to register at 100% capacity when first opened, like Imedions. Could all of these have been sitting around the warehouse or store shelves for 6 months or so longer than eneloops? Possible, but not likely.

But Imedion, among all "low self-discharge" claiming battery brands, significantly outperforms eneloop by about 50-70 flash pops and some 40 minutes of extra flashlight output. So then which one would you choose, particularly for those applications where "low self-discharge" is really ideal but you certainly wouldn't mind getting the extra power out of it?

CONCLUSION:

Someone said that batteries are like human beings in one respect (other than they all die in the end ): there's no perfect battery. Those disposable alkalines are great for convenience with no maintenance but can't be reused, while rechargeables are reusable and therefore economical but needs the user attention and much love.... Some rechargeables are great for performance but not so hot when unused for awhile, while other rechargeables are great for low self-discharge but wilt after some workout. Etc. Etc.

I see the day coming, though, when we'll at least see the marriage between the ever improving low self-discharge technology of eneloop and the ever evolving high performance technology of Powerex and others. Or perhaps rechargeable "AA" lithium-ion batteries might offer a better alternative. Whatever the future holds for us when it comes to batteries, I hope the present "rough" tests would serve you well in your personal quest for the most suitable batteries for your needs.

WOW! Thanks soooo much! I decided to go with Eneloop after reading this. I like the long shelf life!

It would be very interesting to hear a 4 year followup report, about the number of milliamp-hours are now stored in the original batteries, and the number of flashes from a single set, to get an idea of how capacity has declined over four years...at least for the two best performing batteries from the original test!

Wilt wrote in post #16467661
It would be very interesting to hear a 4 year followup report, about the number of milliamp-hours are now stored in the original batteries, and the number of flashes from a single set, to get an idea of how capacity has declined over four years...at least for the two best performing batteries from the original test!

Yes, that'd be very interesting, indeed. Although I've been using the exact same set of Powerex 2700 and eneloop batteries (never bothered to use all the rest!) for the past 4 years, unfortunately I haven't used them heavily to be of much help -- only for occasional flash photography, radios, audio recorders, remote controls and other such non-intensive applications. Nevertheless, 4 years of consistent use is a long enough time to at least come up with my own observations of the following (I'll have to limit my observations to eneloops only, as my past 4 years of battery use was mainly for LSD applications):

1) No perceivable decline in eneloop capacity from their original state to now, i.e., these are truly non-memory affected batteries. I don't even bother to "condition" them and never have; I don't know why some folks even bother to spend so much time doing so with such non-memory affected eneloops.

2) The second generation of eneloops with higher mAh doesn't have the same "long shelf" performance as the original, so my original "laws of battery" still stands, i.e., higher the mAh, less the LSD performance -- no exception, Sanyo or whatever makers. The battery technology is still stuck at 2000mAh for the same long shelf life of the original eneloops. The best that Sanyo can do is to offer a higher mAh at the cost of long shelf life of the original. Therefore, for me personally I still prefer to exclusively use the original eneloops for all applications where alkaline-like performance is needed. I don't waste my money on the second generation eneloops, as I still have the Powerex Imedions that I suspect can do as good a job.

3) Because of my own observations, based on my non-intensive but consistent use of eneloops, I'm more motivated to do a follow-up test after another 4 years have gone by. I don't expect any break-through in battery technology in the meantime, though.

Thanks for those comments. Sufficient to learn that no apparent loss of capacity has occurred. Any idea how many charge cycles the batteries have accumulated so far?

SYS wrote in post #16467843
No perceivable decline in eneloop capacity from their original state to now, i.e., these are truly non-memory affected batteries. I don't even bother to "condition" them and never have; I don't know why some folks even bother to spend so much time doing so with such non-memory affected eneloops.

That's been my observation also. I've been using them since they became available.

Wilt wrote in post #16468212
Any idea how many charge cycles the batteries have accumulated so far?

It's hard to say. It's not like I've been only using the original set or two of eneloops. I got a bunch more since then for all my LSD application needs, so the charge cycles have been spread around, meaning less number of charge cycles per battery. Also, using these for LSD applications means that I don't charge them until they're pretty much all drained unlike the case of flash photography where I'd recharge even when half the juice is drained. Since Sanyo claims that eneloops are good for 1,000 charge cycles, I'll be happy even if half of the claim is true. These will last for years of use unlike those memory affected kinds.

I've been using around 6 sets of PowerEx 2700mah cells for 4-5 years, probably charged around 200 times each. So far I've had two individual cells fail, and when that happens I retire the set of four to general duties instead of professional work (I keep sets together). The ones that don't fail still rate as around 2400 - 2500 mah. I'm pretty impressed with them overall. I've used C9000 and 801D chargers the whole time, both indicate the bad cells easily. I don't bother to try to recover dead cells, but I do a break-in or refresh annually.

I'm moving to Eneloop white just because they're more convenient.

waaaaaaaay toooooooooo much info. see my eyes glaze over and roll back into my head. yikes.

the questions: what's a reliable, worthy rechargeable NiMH battery for a strobe? what's a good charger?

thousands and thousands of words and posts later? dunno.

PS - Tim, after a major case of info-overload, I am following your lead with the Eneloop whites. Here's hoping!

daleg wrote in post #16634711
waaaaaaaay toooooooooo much info. see my eyes glaze over and roll back into my head. yikes.

the questions: what's a reliable, worthy rechargeable NiMH battery for a strobe? what's a good charger?

thousands and thousands of words and posts later? dunno.

Eneloop batteries (amazon link here). Alternately PowerEx cells, higher capacity but they self discharge faster.

Maha C-9000 charger/analyser - GREAT product, does four cells, including a break in cycle and has an LCD display. There's an eight cell Maha here that has fewer features but charges well. I have both.

Using those two chargers the PowerEx cells I bought 5+ years ago and photographed 120+ weddings with are still 90% at 2500mah capacity or better. Two out of 40 have failed. I tend to buy eneloop now, they have enough capacity and lack of self discharge is handy.

daleg wrote in post #16634711
waaaaaaaay toooooooooo much info. see my eyes glaze over and roll back into my head. yikes.

the questions: what's a reliable, worthy rechargeable NiMH battery for a strobe? what's a good charger?

thousands and thousands of words and posts later? dunno.

Well, then, without so many (more) words, get yourself some eneloops and a La Crosse Technology BC-700 charger. Can't go wrong with these.

Or a MAHA charger...

daleg wrote in post #16634711
waaaaaaaay toooooooooo much info. see my eyes glaze over and roll back into my head. yikes.
the questions: what's a reliable, worthy rechargeable NiMH battery for a strobe? what's a good charger?
thousands and thousands of words and posts later? dunno.

Your question is too vague, that's like asking "what's the best camera for taking pictures?" without providing any further details of intended use. Want another exampe? "What's the best car?". I can go on...

BASIC FUNDAMENTALS OF NiMH:
-Low self discharge have limited capacities vs regular discharge
-The higher the capacity, the faster the natural discharge.
-The faster you charge your batteries, the worse it is for their health.

I would say any product from Sanyo, GP, and Maha Powerex is a high quality product. My personal favorite is Maha Powerex.

If you want a higher capacity battery stick to regular discharge.

If you don't want to worry about having to top off the batteries all the time stick to low self discharge.

If you want your batteries to be more reliable over time stick to low self discharge, they last significantly more cycles than regular discharge.

If you want to be get all nerdy about your batteries and spend a little extra get the Maha Powerex C9000. It only charges 4 cells at a time.

If you want to charge your batteries quickly and easily get the Maha Powerex 801D. It takes 8 cells at a time.

If you want to charge your batteries easily and time is not of the essence, and you would like to keep them in good shape long term get the Maha Powerex 800S. It also charges 8 cells at a time.

Each brand I mentioned above makes a regular high capacity battery, and a low self discharge battery with a lower capacity. Sanyo Eneloop also makes a battery which seems to try to be an in between of low self discharge and high capacity called the Eneloop XXX, however, these only have 500 cycle life vs 1000/1500/1800/2000 depending on the battery. The XXX are generally not recommended for flash based on my research.


Hope that's of some help.

Cheers,

POTOMAN

tim wrote in post #16634724
I tend to buy eneloop now, they have enough capacity and lack of self discharge is handy.

Can you elaborate on how the switch to low self discharge is handy in your situation?

How many cells do you find you require on a wedding day?

Thanks,

POTOMAN

POTOMAN wrote in post #16634786
Can you elaborate on how the switch to low self discharge is handy?

How many cells do you find you require on a wedding day?

Thanks,

POTOMAN

Normal rechargeable batteries gradually lose charge when not being used, about 1-2% per day. Good LSD batteries will loose no appreciable charge after a week or two of storage, and retain over 95% of their charge after a month.

So LSD batteries are ideal in equipment that gets used infrequently, because you don't have to constantly top them up to ensure full performance. They are also more convenient IMHO: When I get home from shooting I put all the used batteries in the charger and spares in my equipment, so I'm ready to shoot immediately if something comes up. The next morning, yesterday's used batteries are fully charged and go back into the bag as spares, and I don't have to worry about topping them off for weeks or even months.

Can't help you on the wedding question; when I shot weddings we used battery packs that could go the entire weekend and still be used during the week less critical work. You might want to look at a Bolt Cyclone or Quantum Turbo for wedding work. Not only do they provide all-day power, but improved recycle times to deal with blinkers and speed-walkers.

POTOMAN wrote in post #16634786
Can you elaborate on how the switch to low self discharge is handy in your situation?

How many cells do you find you require on a wedding day?

Thanks,

POTOMAN

When used in an external battery pack, eneloops can last an entire wedding so it makes no difference in real life shooting situations whether you use a group of more powerful batteries than eneloops or not. It's also handy in that you can keep a set or two of these eneloops in the bag as backups or in extra external battery packs all ready to go.