Author Options:

USB power? Answered

I have a 1.2 V nimh battery and a 3.7V li ion (no protection circuitry) battery, which would add up to 4.9V if put in series. However, I want to turn it into a temporary USB power supply (5V) so ignoring all the things regarding putting 2 batteries of different capacities together, is there a way to kick the voltage up a tiny bit? I was thinking something like filtering the output of a joule thief, possibly. I also have a solar panel (4.5V, ???A) and was wondering if that could help, but I don't want to rely on it too much.



Best Answer 8 years ago

4.9 volts would work for usb. I really don't like mixing the different voltages and TYPES.

Go to youtube and search "lithium fire" to see what I mean.

But nobody could tell me anything when I was young either.

Good video.  Can a phone battery do that?

I've got another idea: put 2 li ion batteries in series and regulate with a 7805 IC. Any thoughts/comments?

Use a charger made for lithium batteries and it should work.