NiMh Shoot Out Part II

The original thread is getting a little big, so I am going to close it and we can continue the discussion here in Part II.

The original thread is here.

The test data can be found here.

I will continue to update that first post as I test new cells, and inform you of the updates in this thread.

Tom

Hi Tom. Do you have any Maha Imedions in your testing plans?

Hello Ian,

Unfortunately I stocked up on Eneloop cells and don't have any of the Imedions...

Tom

SilverFox said:

Unfortunately I stocked up on Eneloop cells and don't have any of the Imedions...

Click to expand...

If it's of any help there is a comparison of several LSD batteries which included Imedion and eneloop in a thread by archae86 in AA and AAA NiMH low self-discharge tests--Round 2 over at dpReview.

The best performing LSD AA in that study was the Maha Imedion (IME), followed by the Kodak Pre-Charged (KPC) and GP ReCyko (GRY) - the KPC and GRY curves seemed very similar - almost overlapping. Graphs for AA LSDs

In the AAA LSD graphs - the GP ReCyko AAA (GR8) came top, followed by the Maha Imedion AAA (IM8), then almost overlapping eneloop AAA (EN8) and Duracell Pre-Charged AAA (DP8) (this latter is not surprising, since made in Japan Duracell Pre-Charged are suspected re-badged eneloops).

Followup to earlier 30-day report.


MAHA Powerex 2700 AA cells, 62 day results, discharged @ 500 mA:

Summary
=======
Assumed starting charge: 2620 mAH
30-day results: 2210 mAH (84%)
62-day results: 2155 mAH (82%)


Note: These are extremely small samples (just two cells per test) and the starting charge was assumed (but I doubt if the C401FS @ slow rate put significantly more of a charge than the C9000). The results confirm what has been anecdotally reported elsewhere, that the Powerex 2700 cells have a moderately slow rate of discharge.

1dash1 said:

Followup to earlier 30-day report.


MAHA Powerex 2700 AA cells, 62 day results, discharged @ 500 mA:

2151 ... 2158 mAH
Average = 2155 mAH
​

Summary
=======
Assumed starting charge: 2620 mAH
30-day results: 2210 mAH (84%)
62-day results: 2155 mAH (82%)


Note: These are extremely small samples (just two cells per test) and the starting charge was assumed (but I doubt if the C401FS @ slow rate put significantly more of a charge than the C9000). The results confirm what has been anecdotally reported elsewhere, that the Powerex 2700 cells have a moderately slow rate of discharge.

Click to expand...

I can concur these results. I did a test on 4 x Powerex 2700mAh AA cells late last year. The cells were 14 months old at the time of cahrge, and had been used in a camera for around 12 cycles. Charging and discharging was done in a MH-C9000. Charge rate was 1000mA, and discharge rate was 500mA.

Cell, Initial capacity, 60 day capacity, % retained
1 2557 2188 85.6%
2 2625 2203 83.9%
3 2561 2139 83.5%
4 2537 2150 85.6%
avg 2570 2170 84.6%

Jeff Servaas | Servaas Products | Australian Distributor for Maha Powerex | www.servaas.com.au

Hello 1dash1,

Interesting results.

I believe your, and Servaas's results are similar to what BentHeadTX found when doing similar testing.

Tom

I really like the result table of Part 1, and hoping to see Powerex 2700 added.

Please have a look at this, see second page too.

Sanyo Eneloop vs PowerEx Imedion.

Thanks for the link!

Not surprised. I've avoided buying the Imedions and have been using Powerex 2700's and Eneloops.

Im wanting to buy some new rechargables for my apex for caving. I am guessing that these POWEREX 2700 NiMH are the best ones on the market right now? i can get 4 sets of 4 for $50 off of the thomas-distributing.com site.

So what's the current front-runner? I'm looking to replace my ~100 Tenergy 2600mah AA's that are getting old. I need a decent all-around battery for powering radios, scanners, digital cameras, wireless mice, and of course, FLASHLIGHTS!

Cell durability is more important than sheer capacity. Buying almost a hundred batteries at a time to power all your stuff is obnoxious. Self-discharge rate also isn't that important; they get cycled and charged regularly regardless.

Thanks.

Hello,

I just picked up the Enveloop package from Costco, $28.99, to be used in my only AA light, the LD20 and my Canon SX10IS camera. I also just received a MH-C9000 WizardOne Charger from TD. Now I need to read all the post so that I can get the best performance from these batteries and also my RS and ROV (5 year Old Batteries) AA batteries.

Thanks..

Sort of a dumb question, maybe. I read the test of the batteries on the other thread and was suprised where the eneloop's were on the list. Is the reason that these batteries so good, is from the low discharge rate of the batteries? I am guessing if you want a battery that will last a lot longer off the charger, you go with the 2700 sanyo's or something else. I got the lacross charger and the 2600 lacross batteries. I have to say, those battiers lasted the entire 10 hour cave trip last weekend, where other's went through 2 sets of energizer rechargeables.

I think the 2600 lacross b atteries are pretty good. not sure how well they hold their charge though.

Were they used Energizer 2500 cells? They have a particularly bad reputation.

Silverfox, do you have any experience or testing info on the AccuManger or AccuEvolution LSD batteries? I wonder how they compare to the other cells?

Hello Filibuster,

Sorry, I don't have access to those cells. [Edit: This is not correct. I do have some of these cells and will be testing them in the near future. [end Edit]

Tom

I have been using 8 D cell AccuEvolution LSD batteries in a portable fan this summer. I haven't performed any testing, but I can tell you they have been performing very well in the fan. I run the fan all night (750ma) and charge them in the morning.

Chads93GT said:

I read the test of the batteries on the other thread and was suprised where the eneloop's were on the list. Is the reason that these batteries so good, is from the low discharge rate of the batteries?

Click to expand...

That's part of it. That is the major purpose of LSD cells.

I see a lot of folks refer to Tom's chart in that thread. I rarely refer to it, myself. The real information is in the individual graphs for each cell. The chart is great, if, as you suggest, you are going to be using your cells soon after charging and, are going to discharge them at 1.0 Amp. Other than that, the chart really isn't that useful, other than as a benchmark.

Particularly, where significant current is applied, the graphs paint quite a different picture. If there were a chart representing how well the cells hold voltage under load, for example, the eneloop would be nearer the top.

Dave

Exactly,
I can link to post done by a photographer that compared Sanyo Eneloop vs PowerEx Imedion AAs and it came to the exact same conclusion as the different thread that was linked above. The Imedion gave a slight increase in the number of shots but Eneloops blew away the Imedion on the time it takes for the flash to recycle to full power and ready for the next shot.

LSD batteries and lots of shots are important to a photographer but recycle time of the flash is KING. And this how the general conclusion has been drawn that Eneloops are the best choice in the LSD world for professional photographers using compact flashes. And if anyone cares the Powerex MAHA are head shoulders above the rest in the non-LSD world (yet have been shown to hold their charger very well compared to others).

However, I've never posted this link because we can't necessarily draw the conclusion that they are the best for flashlights.

What needs to be done, is to get one of these reviewers who have SEVERAL models of AA and AAx2 lights and run tests with Eneloops vs. Imedions. Preferably repeating each and every light and battery combo 5 times and taking the average curve from the 5 tests (kicking out any dude cells).

A lot of work but it would give a very good picture of which was better if any.

In our photography work we use Powerex MAHA because they get more shots and they maintain a fast recycle rate for very deep into the curve when compared to eneloops. The kicker is that we have to make sure they are freshly charged right before the event. Because of this we keep on hand a large number of eneloops for situations where we need them quickly or we forget to charge the Powerex's.

For flashlight use I would suspect Eneloops would be the clear choice over Powerex MAHA because of the sexy LSD. However if you need a very long run time in a relatively short amount of time (caving perhaps?) then I would load in Powerex MAHAs if I had both on hand. I certainly wouldn't go out and buy them if I had Eneloops. I'd just carry more spares in my pocket..