AA Battery test

[Glen]

Like many of you with flashes, I have a reasonable collection of rechargeable AA batteries. In fact I would say more than reasonable, I keep on finding AAs everywhere, from the central heating controller which I haven’t used for 9 months, in remote controls, in my PSD, etc, etc. These batteries are everywhere through my house, even in the keyboard and mouse I am writing this with now. I would conservatively say there are 100 rechargeable AAs in my house. This got me thinking, at about $5 per battery, I probably have $500 tied up in rechargeable AA. It is not even my favourite style of battery! I prefer Lithium ion as in cameras, mobiles and notebooks and regard AA as a lightweight consumer battery. After reading comments on this board and elsewhere, I wondered a) if the claims made about some batteries being slow discharge and capacity are true and b) was I using the best charger to look after my (unknown to me) $500+ investment? I also like to encourage the use of good rechargeables, as the cheapskate in me prefers to spend $5 on a battery and use it 500 times, than spend $1 on a battery and use it once. Far, far more important is the fact I would prefer to throw one rechargeable AA into landfill than 500 disposable AA batteries.

I tend to review batteries occasionally, choose the best for my needs at that time, then continue buying that battery till conditions change. For the last few years I have bought Eneloops as their Low Self Discharge suits my usage patterns well. I think that is one point that people should think on, what their usage patterns are. I tend to leave items idle for extended periods, then want them available for instant use. Eneloops do this and work as a direct replacement for any AA battery, non LSD don’t do this as they discharge without use. If my godsons drop in, I can grab my flash, take a dozen shots, even if I haven’t used it for a few months. That suits me where a pro photographer may prefer a slightly higher capacity battery which needs to be charged the day before the shoot, so that they are at maximum capacity for the shoot.

Having decided it was time for a review of my battery choices, I obtained the new Low Self Discharge battery, the Imedion by Maha. If the claims were true, it held a small capacity increase over the Eneloops, 2100mah to 2000mah while being the same price. Maha is also well known on places like Candle Power Forums and often described by members there as having the best AA charger in the world. (have you ever seen someone describe a product as the 9th best in the world? ). The charger with the big reputation is the Maha Powerex MH-C 9000, so I obtained one as well, especially after I realised it was $10 cheaper ($89.95) than my previous most expensive charger, the Powertech Computer Controlled Smart Charger MB 3511 at $99.50 from Jaycar. I obtained this from a member here, servaasproducts (Jeff). This charger has the ability to analyse as well as charge which I thought would be useful for my tests. I also will be selling a consumer level AA torch soon so could justify the research and costs for a charger which really analyses the battery.

The batteries. Naturally I chose my favourite, the Eneloop and as far as I can tell, the only other genuine LSD battery is the Imedion. If I was going to all this effort I thought I should compare it to a better non LSD battery, so chose the widely respected Energizer 2500mah. To give something to keep them honest in the non LSD section, I also got a pack of Powerex 2700mah. I don’t view these batteries as competitors necessarily with each other, more the Eneloop with Imedion and Energizer with Powerex. Let the games begin.

Methodolgy. I am more than happy to have others criticise my methodology as there are many here who have a greater understanding of batteries and electronics, so please feel free to question anything. I wanted to test in a way which was meaningful to photographers, so hopefully my tests will provide that.

I decided to get each set of 4 batteries and put them through the ‘refresh analyse’ function of the charger. I then fully discharged the set in a separate ‘discharge’ cycle. I then fully charged the set in a separate ‘charge’ cycle, but also kept a record of the capacity of each cell, as described by the charger. These numbers are what is available below. After charging, each set of 4 was put into a Nikon SB800 flash. This was connected to a D300 which was then connected to a laptop with Camera Control Pro. The 105mm lens was set to manual focus and aimed at 2 sheets of A4 2 metres away, then the flash was carefully aimed out the window at the neighbour who objected to my Development Application. There was enough spill to light the paper. The SB800 was set to M 1/1 105mm F29 so using plenty of power. I also used the SB800 on 4 batteries, so to give an absolute base level result which most should do better than and to save me buying more packs of batteries than the one I choose. I set the time lapse section of Camera Control Pro to 20 seconds, meaning the camera and flash produced a full flash power shot every 20 seconds, then recorded it to my hard drive. This was convenient as I could stop recording when seeing the flash stop, then review the images till I found the first dark image and count how many flash shots were obtained. I believe this was a fairly successful way of testing, as when the flash stopped I would discharge the batteries for test 2, in all cases the batteries registered discharged in less than 30 seconds, indicating they were fully spent. All batteries (bar the Energizers which must be shipped empty as they took half an hour to discharge) had taken 3-5 hours to fully discharge. I should mention I used the stock discharge and charge rates on the charger, but could have varied them in 100mah increments if I wished.

Electronics experts will be able to tell me what I was measuring in the above test, the battery capacity or recovery or both? I don’t know. To eliminate the recovery part to focus more on capacity, I used the exact same test procedure as above but changed the rest interval to 40 seconds, twice as long. The results of these tests are below:

Capacity - 1st test

Eneloop 1927,2065,1878,1841 average 1927 mah

Imedion 2048,2098,2058,1933 average 2034 mah


Energiser 2266,2385,2446,2379 average 2369 mah

Powerex 2537,2628,2609,2553 average 2581 mah



Flashes at full power with 20 seconds rest:

Eneloop 204 flashes

Imedion 218 flashes


Energizer 242 flashes

Powerex 266 flashes





Capacity 2nd test

Eneloop 1914,1984,2015,1940 average 1963 mah

Imedion 2091,2150,2141,2141 average 2130 mah


Energizer 2362,2445, 2466,2386 average 2414 mah

Powerex 2533,2664,2677,2633 average 2626 mah




Flashes at full power with 40 seconds rest:

Eneloop 197

Imedion 212


Energizer 239

Powerex 265





Conclusions. First I would say it was pleasant to discover that with quality brands the rated mah is roughly accurate. All of the batteries tested were close enough for a cheap bulk consumer item to their specs. By comparison, my neighbour had left some Prolink 2500 mah rated batteries in my PSD when he borrowed it, testing those revealed a capacity in the 1400 mah range!

I view the batteries as 2 different styles, my main interest is in LSD as it suits my usage patterns and I am able to recommend it to customers as a direct replacement for a disposable battery with no education required. So comparing the two LSD batteries, both are good and have close to their rated capacity. The Imedion is rated 5% higher in mah than the Eneloop (2100mah v 2000mah) and in the 20 second test produced 6.8% more flashes, in the second 7.6% more flashes, roughly in line with the claimed capacity difference.

The Powerex is rated 8% higher than the Energizer and in the first 20 second test produces 9.9% more flashes and in the 40 second test 10.8% more, again roughly in line with the claimed capacity difference.

I would be happy to use any of the tested batteries in my flash. As my usage patterns demand LSD and much of the point of this test is to be able to recommend to clients a LSD battery as a direct replacement for normal batteries, my recommendations (if you have similar usage patterns) would be the Imedions. Also I am a bloke, and as any self respecting bloke knows, you always get the 7% more powerful version if they are the same price . On that point, they are the same price, but there is a price break on the Imedions for multiple packets which actually makes them cheaper. There is a price break fom Jeff on Eneloops as well, but I haven't seen that elsewhere. So the Imedions have become my new standard till the next improvement in battery technology.

If you are a pro photographer who has the time and discipline to recharge their batteries the day before they use them, I would recommend the Powerex. Neither Powerex or Energizer would be my first pick for most people, I would suggest a LSD battery first.

There will be 2 more parts to this test, I am now going to rate the chargers after this to see if there really is a difference or it is all just nice screens to make me feel if I have got my money’s worth and as a second test I will charge all 16 batteries and put them on the shelf for 3 weeks (just before my Camera Control Pro trial expires) and retest then.

As it seems that the chargers indication of mah is directly reflected in flashes, I am more than happy to test a sample of any members batteries, so if you have a set of 6000 mah AA made of unobtainium you think are the best, send them over. Feel free to ask any questions and make suggestions where the process could be improved.

[Glen]

Reserved for charger comparison


Edit: To save retyping a direct link to the AA Battery Charger comparison

[Glen]

Reserved for 3 week storage test


Edit: To save retyping a direct link to the AA Battery retained capacity after 3 weeks comparison

[sirhc55]

Nice write up Glen - how’s the typing finger

On Monday I went into a panic because I could not find 8 of my Eneloop batteries. I emailed a client in HK to check if I had left them in one of his products that I had photographed.

To cut a long story short - I immediately ordered the MH-C9000, 8 Powerex Imedion AA’s and 4 AAA’s from Servass. They will arrive tomorrow.

The 8 missing batteries? The client emailed me to ask if I had left them in my dildo as he did not have them Where were they? In my MB-D10, I’m getting too old

[digitor]

Interesting test Glen!

This may turn into a test of the SB-800 flash tube life, but anyway...

Some observations:

I think your methodology is pretty much real-world for photographers.

It's encouraging that your capacity results follow the claims of the manufacturers, they match up well enough with other tests I've seen (and conducted).

Using the break-in cycle on the C9000 will give close to the IEC standard capacity measurements, which is what is used by the manufacturers, probably slightly more than the refresh/analyse results.

It might be useful to measure recycle times throughout the discharge period, as one big difference between cells is their voltage under load throughout the discharge period (probably a tricky thing to measure with your current setup).

I wouldn't want to be your neighbour.

Well done, and I hope your flashgun lives to fight another day!

Cheers

[Glen]

Sirhc, most typing this year!

Digitor, thanks for the tips. I also thought about flash life, that was the 20 second interval. I reckon if they were 10 seconds apart I would have got the batteries to die a bit quicker, but was worried about overheating everything. I would guess this wouldn't be too far off a busy red carpet photographers use for an hour or so, I was aiming for a real life test, though in a fairly harsh manner.. I actually got the capacity measurement from the 'charge' cycle, after the 'full discharge'. I used the refresh/analyse to break them in, for expediency the break in cycle would have taken a while when times by 4 sets. That might be for another test. You are right, I don't think I could accurately measure recycle time.

[Oneputt]

Top stuff Glen. I good review and a bit of an eye opener.....have to go now, have to buy some new batteries

[Greg B]

This is quality work Glen, thanks for making the significant effort and
devoting what must have been a hell of a lot of time to this project.

At the extreme other end from the sort of batteries you are examining,
I buy the el cheapo Alkaline AAs in the 40 pack from Dick Smith (at around $25)
for use in low drain items such as clocks and remotes etc. Obviously, not as
good for the environment, but they last a very long time in these devices and are
effectively a cheap option.

[robert]

Great review Glen,
You got me sending a email to servaas checking my options.

Being a torch man as well, I'm looking for a charger that will charge 18650's as well as standard 1.2v rechargeables (AA and AAA).

Any details on your torch?? the new SSC P7 emitters are crazy! (LED's for those who dont know). I've done a bit of modding- swapped leds etc but no original builds. Well i did make a 5 led cree on a CPU heatsink running off a 14.4v cordless drill battery but it no longer runs!!

Robert

[Glen]

Hi Robert, I know what you mean about the P7 LEDs, bit of a thermal management problem with them from a manufacturers viewpoint Mind you, a lot of light means there has to be some heat. I don't know of any 18650 and AA charger yet. I am a fan of the 18650 too, great battery. Must say, after seeing how good the 9000 is at it's job I wouldn't want to compromise with a jack of all trades charger. The torch I have coming out will be a Q5 single AA unit, 140-180 lumens, something discreet. Seems not all my clients want their torch capable of breaking glass, tearing into wood, etc

[Glen]

To save some PMs, this is the link to member Servaas Products (Jeff) memberlist.php?mode=viewprofile&u=2164

[Matt. K]

Nice work Glen!

[servaasproducts]

Great real world results. There is no policing of the capacity number that manufacturers print on the outside of AA's, thus you will see 2800's and 2900's on the market, but when they are tested, they fall short of the 2650mAh that Glen has measured above.

But what makes this test is even better than a capacity measurement is that it shows the number of flashes acheved, which is what people are looking for. I would be interested to see Shell or Mobil do a similar test with their 98 octane petrol and see whether it really gives better fuel economy!

I look forward to the results of the pending 2nd and 3rd tests.

[aim54x]

i cant wait for the 2nd and 3rd installments, hmm i think i may have to get some of those LSDs soon. atm i am running the Inca 2700 and 2600 batteries, like we do at the camera house that i work at. they seem to hold charge fairly well, but i am not sure how well they compare to proper LSD units. i may have a set of sony CEBs coming my way.

after reading the write up i htink i will have to switch to Imedions or Eneloops, i just dont use my sb-800 enough to keep those incas charged up all the time.

[Glen]

Aim, I should have the instalments up in the next few days, work, real life and Mothers Day slowed me down but like you I was pretty keen to see the results

[sirhc55]

Put an Eneloop in my Wolf-Eyes and managed to light up the Cape of Good Hope for about 1 second before I was arrested for being a public hazard by the South African police. All from Neutral Bay

[Glen]

[Steffen]

Seems not all my clients want their torch capable of breaking glass, tearing into wood, etc

Or frying eggs

Cheers
Steffen.

[Glen]

It is quite a torch that unit Steffen, a well known model and work well (if for a very short time), no need for a stove

[Steffen]

It is quite a torch that unit Steffen, a well known model and work well (if for a very short time), no need for a stove

Yes, 15min run-time is a bit of a joke really, isn't it? But hey, nothing like owning a record breaking toy

Cheers
Steffen.

[Glen]

There are even a few stronger than that but the guy who developed this one custom makes them so this is viewed as a "production" version. I agree, nothing like a record breaking toy

[Glen]

Hi all,

I have got part 2 and part 3 of the test up but a bit busy to post here this afternoon with all the images etc, you can read part 2 comparing AA chargers here: http://wolfeyes.com.au/news/?p=8

[Glen]

Part 3 retained charge comparison in AA batteries http://wolfeyes.com.au/news/?p=8

[stubbsy]

Thanks for all the work on this Glen - very valuable reading

[bwhinnen]

Thanks Glen.

I bought a MH-C204FA charger and 12 x Imedion's yesterday from the aa Servaas stand at PMA Will be giving them a big test out this weekend at the Winternationals. Then will be getting another 8 to round it out to a nice even 20 batteries at a later date!

Been looking over the Wolf Eyes site too, love the look of some of those torches!

[StarForge]

I just ordered myself a MH-C204FA charger and 12 x Maha Powerex 2700mAh batteries after reading your tests! Thanks again Glen!

[Mr Darcy]

Thanks Glen.

I ordered some (20) Imedions after reading your first article few weeks ago.
I checked them with a little battery tester immediately Most registered four dots out of a potential 5 A few registered 3 dots indicating not quite full charge (The tester uses LEDs and claims 1-20% 2-40% 3-60% 4-80% 5-100%)

I put the three dot ones through my charger (LaCrosse BC-900) on refresh cycle. They are still going, but so far are reading
2.13, 2.09, 2.10, 2.16, 2.11, 2.09, 2.12, 2.14 Ah respectively. So even the worst Imedion batteries live up to their claimed capacities. Good to know.. From past experience, they will stay on charge for another week or so. The way the refresh on this charger works is that it discharges, then recharges; checks the capacity, then repeats When there is no improvement between cycles, it stops and switches over to trickle.

When they are finished, I will set up a similar test to yours and compare the 4 dot ones (as bought) to the refreshed ones.

[Glen]

Greg, will be interested to hear your results. I am glad this test has proven useful to a few here.

[DaveB]

I have a mixture of Eneloops and Imedions at the moment (and a big mixed collection of non-LSD NiMHs). I'm planning to get some more AAs later this year, but I'm only going to buy LSD cells.

Today I happened to be in Officeworks and noticed the Duracell and Energizer LSD cells (Duracell notes them as "pre-charged"). They describe themselves as around 2000 mAh, and are similar in cost to the Eneloops and Imedions. But has anyone here actually used them? Tested them?

[servaasproducts]

Today I happened to be in Officeworks and noticed the Duracell and Energizer LSD cells (Duracell notes them as "pre-charged"). They describe themselves as around 2000 mAh, and are similar in cost to the Eneloops and Imedions. But has anyone here actually used them? Tested them?

I haven't, but a user on dpreview.com did a very thorough test of 8 LSD battery brands, measuring the capacity after 1 hour, 1 week, 1 month, and 3 months. Duracell are included but Energizer are not. Of the 8 brands tested, the IMEDION came out on top "by a clear margin" as cited here

As only 4 of the 8 brands are available in Australia, I made an Aussie summary of the results on our blog including nice graphs here or you can read the full dpreview thread starting here

[ATJ]

As only 4 of the 8 brands are available in Australia, I made an Aussie summary of the results on our blog including nice graphs here or you can read the full dpreview thread starting here

What that suggests to me is that the Powerex IMEDION are closer to 2200 mAh than 2100 mAh. The rate of self discharge seems to be pretty similar between all the batteries and the Powerex IMEDION start at a higher capacity.

[Mr Darcy]

What that suggests to me is that the Powerex IMEDION are closer to 2200 mAh than 2100 mAh. The rate of self discharge seems to be pretty similar between all the batteries and the Powerex IMEDION start at a higher capacity.

Except that if you look at the tested capacities of my cells above, they are all pretty close to 2100mAh the ones that are at full capacity so far read 2110, 2090, 2120, 2130, 2160mAh. Still waiting on 3 cells. Only one cell so far is closer to 2200 than 2100.

Mind you if they are closer to 2200 on balance (I chose to charge the ones at lowest residual charge out of the packet) then I for one am not going to complain.

[ATJ]

Mind you if they are closer to 2200 on balance (I chose to charge the ones at lowest residual charge out of the packet) then I for one am not going to complain.

And I won't complain, either. I was merely pointing out that in the long test, the discharge rate of the IMEDION cells was no better than the others (except the enloop), it was just the starting capacity was higher. In fact, the IMEDION lost 11.25% over 3 months where as the Duracell only lost 9.4%, the Uniross 10.8% and the enloop 11.8%.

[servaasproducts]

Except that if you look at the tested capacities of my cells above, they are all pretty close to 2100mAh the ones that are at full capacity so far read 2110, 2090, 2120, 2130, 2160mAh. Still waiting on 3 cells. Only one cell so far is closer to 2200 than 2100.

The first manufactured batch of MH-C9000 (with batch number 0Fxxxx) were 6% optimistic on the capacity measurements. That may explain why the tester on dpreview.com has results are higher than other peoplesbattery measurements. Keep this in mind if your MH-C9000 has a batch number OGxxxx or OHxxxx. Still, he uses the same charger for all the batteries, so the capacity and discharge rate comparisons are still valid.

[Greg B]

You blokes really do some serious battery work.

So just for interest, I am going to mention my 15 minute Vartas.

I have not done any testing of their capacities or retentions or anything else for that matter.

However, I have had the first batch of 16 for almost four years. They recharge in 15 minutes. That
is extremely handy. They are still going strong. I use them in the SB800, and the Canon S3, and they
seem to last well. And they recharge in 15 minutes!

[ATJ]

So just for interest, I am going to mention my 15 minute Vartas.

Greg,

How long do the 15 minute Vartas take to recharge?

[Mr Darcy]

How long do the 15 minute Vartas take to recharge?

They recharge in 15 minutes.

The first manufactured batch of MH-C9000 (with batch number 0Fxxxx) were 6% optimistic on the capacity measurements.

Except that I was quoting MY results and I used a LaCrosse BC-900 (Well two actually) but yes, I have no confirmation of their accuracy, only their precision

Still waiting on two cells to reach full charge. They are both on a discharge cycle ATM, so it will be at least another day.

[Greg B]

So just for interest, I am going to mention my 15 minute Vartas.

Greg,

How long do the 15 minute Vartas take to recharge?

Yes, I did mention it a couple of times

But geez it is handy

[servaasproducts]

Except that I was quoting MY results and I used a LaCrosse BC-900

My comment still stands: If the dpreview tester is using a MH-C9000 manufactured in December 2006 (batch 0Fxxxx) and the BC-900 is accurate, his results will 6% more optimistic than yours.

[RDW]

Great review and thread Glen! Plus additional info from other contibutors. Rechargeable battery shelf life and subsequent battery life has been frustrating me for some time now, I was nearly ready to give up on rechargeables. This discussion appears to provide the answers for AA & AAA solutions.

Does anyone have similar info / advice re other NiMH, Li-ion, Li-ion Poly battery Packs at varying voltage / capacities, eg 7.4V 2200mAh, 10.8V 3600mAh, 14.4V 4400mAh and appropriate chargers?

Is there such an animal as a Universal charging pack which could be applied to quality battery management over a range of voltage/capacities eliminating 10 kazillion charger packs?

Feedback would be appreciated.

Now to dispose of about a dozen charges and buy one good one and some new batteries. Thanks guys.

[Glen]

RDW, the Maha Powerex Wizard One MH-C 9000 is often called the best in the world in AA & AAA chargers, for lithium ion (which should have no self discharge problems, balancing is more of a li ion problem when in packs) the Schulze line of li ion is recognised as one of the best and will also do ni mh but requires you to set up the connections (as it does for li ion). German quality doesn't come cheap though, the price is 250 to 550 Euro! Makes a $90 Wizard One seem a snip.

[RDW]

Thanks Glen, had a look at the Schulz link you gave and it all looks too much like foreign interpreted tech talk to be of much value to me. Your tests and explanations all made sense to me on the AA, AAA options. A lot more reading and learning to get my head around the packs I guess. Thanks again.

[Mr Darcy]

I tried the test (similar to Glen's) I mentioned above and got very strange results.
Refer this post for what happened to me:
http://www.dslrusers.com/viewtopic.php?f=44&t=33380

Basically I got 11 flashes from one set and 42 from the other, but the Flash ready light was still coming on, and the batteries measured as nearly fully charged in my tester. I think something weird is happening with my SB800s

I am keen to hear suggestions.

[Glen]

I have just finished the 3 month test of AA batteries for retained capacity, to save cutting and pasting here is the link http://wolfeyes.com.au/news/?p=25

[aim54x]

nice to see that there is a difference between the low self discharge and the high cap batteries, but it really begs the question as to whether it is worth the extra to get those low self discharge batteries if they are only about 5% better. BTW are you continuing this test for 6/12 months?

[Glen]

Not sure whether to continue the test for 6-12 months if I thought ahead I would have charged 2 sets of every battery, then I would have to only wait 3 more months for the 6 month test. As it is now I have to wait 6 months! I think the 3 month test gives a good indication of expected performance in a likely situation for a photographer.

[aim54x]

Not sure whether to continue the test for 6-12 months if I thought ahead I would have charged 2 sets of every battery, then I would have to only wait 3 more months for the 6 month test. As it is now I have to wait 6 months! I think the 3 month test gives a good indication of expected performance in a likely situation for a photographer.

That is a good point, if you are not charging after leaving your batteries for 3months then you deserve to pick up empty batteries. it would have been interesting to see if there is more of a drop off after 6 and 12 months though.

Good work with the testing Glen

[servaasproducts]

nice to see that there is a difference between the low self discharge and the high cap batteries, but it really begs the question as to whether it is worth the extra to get those low self discharge batteries if they are only about 5% better.

The results look quite good for the higher capacity batteries in this test, being that they are brand new, and still holding their charge quite well. I expect a test on the same batteries after 30 to 50 cycles would show a greater difference in discharge rates, with the higher capacity batteries not holding their charge as well as they do when they are just a few cycles old. I have had plenty of customers note that their rechargeable batteries are totally flat after a week without any use, I wont mention any brands!

[Glen]

I was going to say the same, these tests were with brand new batteries to be fair to all. I have just stuck 4 Energizer 2300 in the Wizard One on refresh/analyse, will let you know what capacity they come up with even fresh off the charger. Will also do the same with a set of Eneloops, just so we have some basis of comparison.

[servaasproducts]

I was going to say the same, these tests were with brand new batteries to be fair to all. I have just stuck 4 Energizer 2300 in the Wizard One on refresh/analyse, will let you know what capacity they come up with even fresh off the charger. Will also do the same with a set of Eneloops, just so we have some basis of comparison.

An unhealthy battery will take a charge, but will not hold a charge, just like an old man can still drink beer, but how well he holds his liquor is another thing

A more important result will be to see how much of their power the older energizer and eneloop have 2 weeks after the charge. I hope other MH-C9000 users can do the same with their old batteries and share the results - it would be interesting to see how well, or poorly, the older cells are retaining their power.