I was wondering if I could use a battery as Vin to a DC DC converter to charge another battery.
Example: Using a Li Ion battery pack and having it go through the DC to DC converter to charge a LiPo battery pack.
More specifics: My idea was to have a Li ion pack be able to charge a Lipo pack by going through the converter or press a switch to have the Lipo pack charge the Li Ion pack. I'm wanting to be able to charge either batteries while using it. Like flying a drone or using an eboard etc.
While in flight for example be able to use a Lipo pack as the source supplied to esc while being charged by the Li ion pack, or use the Li ion pack as the source supplied to the esc while being charged by the Lipo.
Batteries: Li ion 4s2p (3.7/4.2v 20/40 amps per cell) Li po 4s (1500 mAh supposedly 120c)