Electric Battery Charger

Electric Battery Charger
How do the voltage and current of a charger relate to the voltage and current of a rechargeable battery?

I was trying to figure out how many volts or the amount of current I would need if I was to make a battery charger. Depending on the type of battery would I need to make sure the voltage or current is correct, and would the volts need to be above or below the voltage of the battery? Sorry if I don’t have some of the electric principles down, but I couldn’t find an answer anywhere else, so any help would be very much appreciated. Thank You!

The charger voltage will always need to be above that of the battery voltage to be able to force current in the right direction. the only other part required for lead-acids/nicads is a limiting resistor or current regulator.

All other battery chemistries require specialist IC’s…. especially Li-ion and Li-polymer.

1908 Car Battery Charger with Mercury Arc Rectifier