Forums » General Electronics Discussion

Hi,

I'm a beginner at this, so I'd like some advice. I want to be able to recharge small Li-Ion battery packs (for my drone) in the field. Fortunately I have a great power source to hand, namely my e-bike which has a huge 14S Li-Ion battery (about 58.8V when fully charged).

I have a charger (for the drone batteries) that's rated up to 53V, so I can't just hook it straight up to the bike battery (well, I could try, but I might fry it), but I could use a voltage divider to reduce the voltage to something usable, and then use an off-the-shelf voltage regulator to keep the "remaining" voltage at 5V, because a 5V supply would be a very handy thing to have.

So yes, a straight forward voltage divider would do it, but is there a better, more efficient way of doing this so that I'm losing the minimum amount of energy from my e-bike battery?