Instructables

how do I convert 2 AAA batteries to AA

I have an electronic device that uses two AAA batteries internally. Instead of replacing them every couple hours, is there a way to use AA or other batteries to extend the life? The AAAs are encased in a closing lid, so there's no room for AAs but I am thinking there should be a way to solder some wires to connect them. On the slow drain usage, the 2500 mAH AA should last 2-3 times as long as the 900mAH AAAs. Is this correct? And is there a way to put more batteries in battery pack [series or parallel] without frying the device? Thanks for any feedback.

shinyhalo2 years ago
I have a wireless transmitter 1mw, 180hz, 2400ghz link that needs more power and range.
Would changing the puny 2x AAA batteries to one larger battery increase the transmitter's range and power? If so, any recommendations for a specific battery?
Gabs5 years ago
which AAA battery last longer?
I know this is an old thread, but I think I have a better solution..

Get yourself a couple of lithium cells in aaa form factor (search for 10440 batteries.. or maybe 10430.. dealextreme.com is a good place to get batteries and charger cheap.. shipping is slow though).. Modify your device so that they go in in parallel instead of in serial (serial == positive -> negative , parallel = side by side with both positives hooked to the + side, and both negatives on the - side).. This should work because the lithium batteries run at a little more than twice the voltage, so in parallel they should be about the same.. Lithiums also have a much higher energy density than the other battery types and are recharg3able.. You should get about twice the life out of your device, and everything will still fit inside.. An $8 charger will let you reuse the batteries like 500-1000 times, and when the batteries do go bad, they do so gradually so you can squeeze more life out of them if you like.
danmarycap6 years ago
I have a related problem -- hope someone can help!

I want to power a portable stereo that needs 8 D-cell batteries (total of 12 volts). I tried using 8 D-cell NiMH batteries, but that only totals 9.6 volts (1.2v x 8). My theory is that if I use 6 of the D-cell NiMH batteries (total of 7.2v) and 2 D-cell adapters (each containing two 1.2v AA NiMH batteries, wired in series to produce 2.4v each), I'll get to the required 12 volts.

Assuming I've thought that through correctly, does anyone know of an adapter that will allow me to use 2 AA batteries in series as a 2.4v D-cell? Will the Soshine AA adapter at DealExtreme work? DealExtreme
bth86 years ago
idk y you would want to b/c aa and aaa have the exact same voltage (1.5) as btw do aaaa c and d batteries
LasVegas7 years ago
In most cases, two AAA batteries will be connected in series (one up, one down) and can be replace with any other 3VDC supply. If you look, you'll see that the two batteries are connected together with a plate. The contacts on the other end of each battery are the respective contacts to feed the power into. Solder a red wire to the one that the positive end of the battery connects and a black wire to the other one. Now, you can connect any combination of batteries that give you 3 volts.
Aeshir LasVegas7 years ago
I tried doing something similar to my MP3 player, and it stopped working after a while. I noticed the voltage on the AA was 1.2 volts (NiCd) and the AAA was 1.5 (which it originally ran on). It still works with the AAA by the way.
That's the problem with rechargeable batteries. They use 1.2V instead of 1.5V, and many electronics don't work on 1.2V (or 2.6, if it uses two.)Seems dumb to me. If a D-cell can put out the same voltage as a AAA, then the voltage is not related in any way to the size of the cell, so a AA NiCd or NiMH should be able to put out 1.5 volts. But they don't. Who's dumb idea was that?
It's not the size of the battery that defines the voltage, but the composition. Size defines capacity. Both the composition and size define the available current. Lead/Acid batteries supply 2v per cell, Carbon/Zinc and Alkaline supply 1.5v, Nickel/Cadmium supplies 1.2v, etc.
Yeah, yeah, I knew that already. It just seems that someone could modify them to put out 1.5V.
No. A cell performs as it performs. It's chemistry, not mechanics.
Could it work to use resistors?
No. it couldn't.
BoomGuy Aeshir7 years ago
Most rechargable batteries are only around 1.2 volts. Most device can still use them. Did you try recharging them? Did you check that they held the charge?