3 ms·
For any 2xAA or 2xAAA device without a center tap, you can use a 3.2 volt LiFePO₄ cell with a "0 volt" spacer. I use LiFePO₄ to run my rear bike light and a wi
by p1mrx 7y ago
For any 2xAA or 2xAAA device without a center tap, you can use a 3.2 volt LiFePO₄ cell with a "0 volt" spacer.
I use LiFePO₄ to run my rear bike light and a wireless thermometer, both 2xAAA devices. The total capacity is reduced because half the space is wasted, but that's not a big deal if you're only recharging a few times a year.
I haven't tried this with remote controls, since the batteries last basically forever in those.
Another option is to use 3.7 volt lithium ion with an LDO regulator, but I haven't tried that yet.
- bdamm 7y agoFun hack! Do you have a line on cheap LiFPO4 or is it just to get a longer run time between swaps?
- p1mrx 7y agoI prefer not to use disposable batteries for environmental reasons. But with NiMH, a light designed for 3V will be dim, and an LCD will have low contrast. In that sense, the effective run time is zero, so NiMH is a non-starter. I found some AAA-size LiFePO₄ cells, spacers, and a charger on AliExpress a few years ago.
- extesy 7y agoLDOs introduce their own inefficiency into the process so it's usually not worth the trouble.