Tracking batteries to monitor capacity

[moz]

There's been a thread on testing AA batteries brought on by people buying the
La Crosse BC-900 chargers that let you measure capacity. It makes sense to use batteries with the same capacity together, but they all look the same.

Now that I have my own copy of that charger I'm stuggling to keep track of which batteries have been tested and what their capacities are. Permanent marker seems to wipe off the batteries quite quickly and engraving them with capacity when that changes over time doesn't seem useful.

I'm thinking of engraving an ID on each battery and keeping a spreadsheet but that seems geeky. On the other paw, I do have over a hundred AAs floating around to keep track of, so I probably am geeky already. Alternatively I could tape the label on or use heat-shrink tubing.

Does anyone have a solution? Or other ideas?

[Yi-P]

I use fine tip permanent marker, mark them as group 1, 2, 3 for my SB800...

each group consist of 4 batteries from the same packet (no, I didnt test the capacities myself).

They are then kept in battery holders of 4 and charged in groups of 4...

How hard you trying to get it?

For other power devices, I dont really care about that, and I dont have hundred of AAs at my disposal...

[moz]

At the moment I'm taping IDs to cells and hoping for the best.

Testing the batteries is interesting - I've been keeping sets bought together in groups, but the capacities vary by ~20% in some groups. Testing means I can group batteries by capacity and hopefully get more usable power out of the cells. Of course that breaks down a bit when I'm using 10 at a time in the flash, but for more things it's useful. What I want next is to test leakage/self-discharge rates so I can pick cells for my LED bike lights. But I'm not sure how to measure that, perhaps by waiting a week then measuring time taken to recharge.

Once I have a few results I'll post them to the battery capacity thread.

[Aussie Dave]

Just curious as to how much more efficient grouping like-capacity batteries is and is it worth the time & energy spent on it ? (pardon the pun)

I'd be surprised if many of us here have more than a couple of sets for our speedlights or flash units....so keeping track of them may not be the issue it is for yourself, being you have 100+ batteries and monitor their charge very carefully.

I'm not disputing you need these, nor should change your way of operation. I'm just not sure how worthwhile it would be for the "average" photog to be concerned about it ?

[Glen]

Dave, big difference according to this little test. http://www.flashlightreviews.com/features/123burst.htm

The summation is matched pairs (even dead) work better as the full battery isn't trying to recharge the dead.

[Mr Darcy]

I don't have a fancy charger that tells me actual capacity, so I rely on the labelled capacity.

I use different brands/capacities to help me keep sets together, but keep to known brands in the - possibly vain - hope that these are more likely to live up to their advertising.

I keep one set in the SB800, one in the SB600, one in the GPSr, one in the bike lamp, one in the radio and one floater in a pouch. I use a 30 minute charger if I am desperate (I usually am!) otherwise a 19 hour one. If I am away from a charger and desparate, I raid the least important device, usually the GPSr

I have gone back to disposables for clocks & the like as they seem to last for their shelf life anyway.

Greg

[gstark]

To keep "like" batteries together, why not use coloured shrink wrap?

You could cut these into smallish bands, and thus mix and match sets of bands - not unlike resistor banding - to give you groups of unique ID tags that you can quickly and easily recognise.

No looking for engravings, no worrying about marker writings being wiped off.

[Glen]

Gary, great simple idea

[moz]

To keep "like" batteries together, why not use coloured shrink wrap? ... like resistor banding

That is a good idea, and one that I was thinking about, but sitting at home last night I decided to try the paper+tape since I had the materials to hand. I'm slightly concerned about the heat shrink insulating the batteries so they get hotter than otherwise, but not so much that it'll stop me looking for more colours of heat shrink next time I'm in jaycar. I have 4 colours lying around (from labelling climbing gear) but more is always better

I've tested about 26 batteries so far, but that's just the bag'o'batteries I keep next to the charger. Now that I've only got one charger (HangDog bought the other one) I'm going to re-test 8 of them on a faster charge rate to see if that makes much difference, then use that to get a faster test cycle (2400mAH at 100mA discharge/200mA charge means 36+ hours for a test cycle).

[Matt. K]

Throw away all of your crappy made in China batteries and buy Sanyo Eneloops 200mAh. They will have more punch and keeping power than whatever you are using now. Charge them up and put them in your bag and forget all about them until you need them. The Sanyo 2700mAh tubes are also outstanding but don't hold the charge like the Eneloops.

[fozzie]

Matt. K - I concur with Matt's comments about purchasing the Sanyo ENELOOP Rechargable 'AA' 2000mAh batteries. I purchased 2 packs of 4 about 6 weeks ago, and they are still going strong. Also bought some 'AAA' with the same result. Marvellous technology

Throw away all of your crappy made in China batteries and buy Sanyo Eneloops 200mAh. They will have more punch and keeping power than whatever you are using now. Charge them up and put them in your bag and forget all about them until you need them. The Sanyo 2700mAh tubes are also outstanding but don't hold the charge like the Eneloops.

fozzie

[digitor]

Yes, these Eneloops are great! They've got plenty of grunt for recycling flashes quickly, and in my limited completely unscientific tests, in this regard they outperform much higher capacity cells. Their specs indicate a very low internal resistance of 25 milliohms @ 1V, which gives a theoretical short circuit current of around 40 amps.

Cheers

[Yi-P]

Buying 3 sets of eneloop cost about $60 + s/h, its a good deal but I still have few sets of Duracell 2300mAh here, maybe I should just stick to the Duracells for the moment, they're performing great at the moment...

[Matt. K]

I have seen them on the net for under $5 each. Shop around.

[fozzie]

Yi-p, Use the Duracell's for the battery operated toothbrush, TV & DVD controllers etc., and use the Sanyo's for your flash

Buying 3 sets of eneloop cost about $60 + s/h, its a good deal but I still have few sets of Duracell 2300mAh here, maybe I should just stick to the Duracells for the moment, they're performing great at the moment...

fozzie

[phillipb]

All this talk about batteries reminded me of the problem I was having with mine, I used to leave them in the flash but they discharged very quickly and they were flat every time I went to use the flash. I was blaming the SB-800
So I charged them up and left them in the camera bag. I just went and tried them in the flash and.... you guessed it, they're flat. they are Energiser 2500mAh. might have to look for some of those Eneloops.

[phillipb]

Are these any good?
http://cgi.ebay.com.au/SANYO-2700mAh-NI ... dZViewItem

[moz]

Throw away all of your crappy made in China batteries and buy Sanyo Eneloops 200mAh. They will have more punch and keeping power than whatever you are using now.

You seem very certain of that. Are you offering to buy the Eneloops off me if I'm not completely satisfied?

I'm just skeptical that any 2AH battery would have more usable capacity than a 2.5AH 5mΩ battery. But I'm willing to pay $20 to find out, I suppose. The usual 1A discharge test is what you're suggesting, or are you counting flash cycles per minute or something?

[adam]

I liked the writeup by David Burren.
http://burren.cx/photo/AAbatts.html
He's got the measured capacities for different batteries.

Mine batteries are easy to differentiate, because I often buy different brand sets of 4...haha, except for the Sanyo ones, I've got 8, but 4 of them have a discharge issue, so now it's all mixed up

[DaveB]

Most of the numbers in that article are found in this DSLRUsers thread (i.e. I used some of johndec's numbers as well as my own).

One thing our testing has NOT measured is the self-discharge rate: it is entirely possible that a given set of 2000 mAh cells may have more charge remaining after a couple of days than a given set of 2500 mAh cells (if those particular 2500 mAh cells self-discharge faster).

Setting up a test regime to test all that out is a bit daunting though...

[Matt. K]

phillipb
They are reputably the best batteries currently available on the market today. They do not have the Eneloop technology of low discharge, but they zap fat and last for a long time (Information from a number of reputed websites_

[Matt. K]

Moz
I purchased a set of Eneloops, took my 2500s out of my Sb800, took of the 5th battery holder, put in the 4 Eneloops and kept zapping the SB800 at F11 until I got bored. The ready light kept coming back faster then I have ever seen it do before. Not scientific but I was satisfied. The batteries had been charged by the manufacturers 3 months before I got them. That's 2 out of 2 for me. Sanyo are the Rolls Royce of rechargbable AA batteries according to a number of battery freaks who measure and test this stuff to the ninth degree.

[moz]

OK, the Australian supplier has datasheets for them on the web (click the pdf link) and all 3 variants are 25millohm. Consumer cells for low rate of discharge operations. Great for LED lights and other low-drain situations. On the bike the Eneloop cells look ideal.

For the flash I'm sticking with the low impedence cells I use now, Intellect 2000 AA (cheaper shipping than other suppliers)