Does a AA battery dressed as a C battery work the same as a real C battery?

January 18, 2012 4:08 PM

How do rechargeable AA batteries in C-battery sized spacers (like these) compare to standard C batteries?

Baby Xalf is coming soon, and we are acquiring lots of electronic baby gizmos (things like this and this) that run on C batteries. Can I save some money and landfill space by using this type of rechargeable battery? Or should I use a different type? Or just stick to standard batteries?

posted by Xalf to technology (9 answers total)

They don't last as long, if nothing else. As described in this list of batteries by maker, AA batteries will hold between 1850mAh and 2600 mAh, while D batteries go up to 11000 mAh. You might need to buy more batteries to have some that are charged, but that's about it.
posted by filthy light thief at 4:18 PM on January 18, 2012

They won't last as long (the energy contained in an alkaline C-cell will be more than three times as much as the energy in one of your AAs). Not a huge deal as long as the power draw is low enough (they just won't last as long). If the draw is significant though, you'll drain your AAs very quickly (you get less energy if you pull more of the power out at once).

NiMH C cells are not particularly expensive, even with a new charger.
posted by ssg at 4:26 PM on January 18, 2012

OK, that was pretty easy. Any recommendations on brands of batteries and chargers? Or are they all the same?
posted by Xalf at 4:45 PM on January 18, 2012

For the true geek.

_{We have one. Sometimes I watch the numbers go up.}
posted by katrielalex at 5:01 PM on January 18, 2012 [2 favorites]

Buy the Eneloop batteries. Don't buy the Energizer batteries. We have about 20 of each. The energizer batteries lose their charge after about 3 weeks or so, which means every time I pull one out of the drawer, it doesn't work, and I have to charge it again to use it. The Eneloop batteries are supposed to hold a useable charge for several years, and I have pulled some out of my drawer that haven't been charged in 3-4 months, and they seemed to work just as well as one which was just charged.

The only place I know of that carries the eneloop batteries at a retail store is costco, although we haven't found them at all costcos. We order them off of Amazon.

We have about 20 AA and 4 AAA, and the AAA rarely ever get used. The AA's are constantly in use. I don't know if we have any baby toys which use AAA's other than the sound puzzles, pretty much everything needs AA or D.
posted by markblasco at 5:30 PM on January 18, 2012 [1 favorite]

Eneloops are also brilliant in things like remote controls or cordless phones, where they spend the majority of their time just sitting there. I get like 6 months out of a charge on the Eneloops in my Harmony remote. A month with the old-style batteries.
posted by kindall at 5:36 PM on January 18, 2012 [1 favorite]

If you're buying online (and you should), go directly to Thomas Distributing. Best rechargable battery shop on the Internet and they'll set you up with exactly what you need. I've been buying from them for twelve years now, I think.

Last time I bought a bunch of rechargables Maha Powerex was the go-to, and I guess now it's Maha Imedion, although I see Thomas is featuring Eneloop so that can't be a bad bet either. The Maha and Accupower chargers are great.

One advantage of Maha over Eneloop is that you can get actual 5-10,000 mAh Cs and Ds instead of using low-capacity AAs in a spacer. (But then you need to get a charger that fits them. but Thomas will have that too!)
posted by mendel at 6:45 PM on January 18, 2012 [1 favorite]

Rayovac makes actual C cell rechargeables that are pretty cheap. They have a higher rated capacity (3000 mAh) than any AA cells.
posted by eelgrassman at 7:36 PM on January 18, 2012

I have a La Crosse Technology BC-900 AlphaPower with more Eneloops than I can count and they are fantastic.
posted by Brian Puccio at 6:32 AM on January 19, 2012