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Adventures in Rechargeable Batteries


Not only am I a geek, but I also have toddlers and a preschooler. We go through batteries. I haven’t done any comparisons of battery brands or rated mAH, I generally buy whatever batteries are at the store I’m in when I realize “We just bought another toy that requires batteries”. Plus I like to keep a reasonable amount of charged batteries ready to go for when I pull batteries out of something to charge them.

Because of the wide variety of form factors in kids toys I needed a charger that could charge C, D, and 9-volts as well. The only one at the time was a Radio Shack that was a fast charger (or claimed to be, it wasn’t particularly fast in practice). I also bought Radio Shack batteries. I blame sleep deprivation. About a year ago it died and I found the Energizer Family charger which is a slow charger and has worked like a champ.


Does look cool. Anyone one a canadian source that doesn’t cost more than double the US price?


Thank you! I have three (lost one) of the 2500mAh Energizer you show, and they’ve been getting weaker and weaker and I had no idea why. Now I know, and knowing is half the battle. I see a new battery charger, and maybe some Eneloops, in my future.


If anyone knows where can I buy it in Argentina, please let me know!

I couldn’t find it anywhere…


Does anyone have any experience with using NiMHs in game console controllers (i.e. wireless GH3 guitar for the 360 or Wii remotes)? I’ve been using regular Energizer alkaline AAs in the wireless guitar controller but I’ll go to use it after letting it sit around unused (for a few weeks or so) and the batteries always near death.


How about 9v batteries?


As to why we don’t use Lithium Ion AA cells, it’s because they’re the wrong voltage. A lithium chemistry cell has a 3.7V nominal voltage. Nickel-based batteries are 1.2 - 1.25V, pretty close to the alkaline and zinc-carbon’s nominal 1.5V. Make an AA cell with lithium chemistry and you have a recipe for disaster. Some devices that otherwise take two or three AAs have a lithium-based rechargeable pack, so the voltages are a lot closer.

There’s a large amount of information about rechargeable batteries at http://www.batteryuniversity.com/


Man you’re psychic. Just last night I had to change the batteries in my camera, and I lamented our drawer full of rechargable batteries that just don’t seem to hold a charge anymore. I know the cheap Energizer charger we had was crap, and thought, “I should look in to getting a decent battery charger some time, might be able to save those batteries.”

And today, here’s the article. :slight_smile: Ordered the charger, thanks for the great info!


@Jeff - I have the BC900. From memory, I don’t think it has two mAh displays. I think there’s one mA display, which is charge/discharge rate and one mAh display, which is the total energy that has been stored/discharged.

But anyway, I definitely agree that it’s a great charger, and likewise that Eneloops rock.

@Craig - I routinely use NiMH batteries in my normal 360 controller with no problems. I don’t have the guitar hero controller so I can’t speak to it.


Lithium cells are no good for AA/AA use as the voltage of a cell (~3.6V) is far too high.

Also when looking a battery capacity self-discharge isn’t necesserily the problem, it’s the amount of current your drawing. Capacity vs. current draw isn’t linear, and the amount of deviation from the linear relationship varies from battery to battery. Capacity thus isn’t a terribly useful measure - a 2000mAh labelled battery might well perform better that a 2800mAh battery at high draws.


I got a BC-900 and some Eneloop AAs for Christmas, and they are indeed very good.

I’ve been using the Eneloops in a cordless mouse. That’s a relatively low-drain device, which has traditionally been a weak spot for NiMH batteries. But the Eneloop cells seem to last at least as long as alkalines do.

It’s a shame that just as we’ve finally figured out how to make really good standard-size rechargeable cells, so many gadgets are moving toward proprietary, expensive, hard-to-replace custom battery packs.


Speaking of energy, my oil heating bills are bankrupting me! I’d really appreciate a well-researched article on how to replace my heating system with solar energy. Just one of my oil bills could probably pay for some solar panels.


Hey Now Jeff,
AAA AA’s huh, learned more than I ever could about them by reading this one.
Coding Horror Fan,


I used to be a rechargeable battery geek.

If you buy online, ordinary alkalines are a lot cheaper then they used to be. I just bought 200 AA alkalines for $30 from a seller on eBay. They work great in radios, cd mp3 players, kids toys, etc.

For the high drain items, get the single use Eveready AA lithiums. They are more expensive, but they last a long time. The only thing I use them for is the DSLR and flash. A set is good for 800-1000 captures. Not bad for $6.00 at Sam’s Club. And the best thing: they weigh about half of a typical NiMH battery. Makes the camera noticeably lighter.

They are also good if your rechargeables die unexpectedly, since they are available everywhere.

No more AA/AAA battery and charger hassles for me.


I used rechargable batteries ever since I started to use a digital camera, which uses up batteries in two hours or so. Now I use rechargable batteries for nearly everything, and it’s an excellent way to save money (and the planet). Believe it or not, in Argentina rechargable batteries weren’t widely available until last year (that is, you couldn’t get them at any supermarket). Now, every single supermarket has them, and now Sony recently launched rechargable batteries which have very low discharge them (according to them). Now, if I could get that awesome recharger…


The ‘magic smoke’ escaped from my 3 month old BC-900. I called LaCrosse and they offered to replace it no questions asked.

I’m curious if anyone else has experienced this issue?


I just bought a BC-900 from thomasdistributing.com about a month ago and I’m loving it.

If you’re thinking about getting one, there are some precautions to be taken, though.

This charger uses a -dV primary charge termination algorithm, so it’s highly, highly recommended that you don’t charge at a rate below C/3. It’s actually better if you charge anywhere between C/2 and 1C. That means for a 2000 mAh battery, your charging rate should be at least 1000mA (C/2) but not greater than 2000mAh (1C). If you don’t do this, you run the risk of missing charge termination and damaging your batteries to the point that you’ll get way fewer cycles out of them.

Also, the circuitry inside this charger is pretty inefficient, so quite a bit of heat is generated at higher charge rates. It’s a good idea to prop the back of the charger up on something to increase air flow under it. Otherwise, you’ll get your batteries so hot that the thermal cutoff point will be hit and charging will temporarily stop to let the cells cool.

And finally, there have been several reports of people with firmware v32 having melted batteries and charger because of the aforementioned thermal problems. Please make sure that you get this charger with v33 firmware. The thermal cutoff is lower and therefore safer on the newer version. I don’t know about amazon, but thomasdistributing only keeps the latest firmware version in stock.

Anyway, it’s just good to keep in mind that all rechargeables are somewhat dangerous, especially so when charging. NiMH are not nearly as dangerous as Lithium-based chemistries, but it’s still a good idea to keep an eye on your batteries when they’re recharging.

Great writeup, as always Jeff. I completely agree that Eneloops or any other hybrids with low self-discharge are the way to go.


besides remotes, I can’t think of anywhere i use replaceable batteries.



There’s a recent report here on CandlePowerForums http://www.candlepowerforums.com/vb/showthread.php?t=191052 of a guy with a meltdown. See pics in Post #6, 7 and 8. His charger was a v32, though.


grrr, here’s the link