Lets see - -
An automotive Pb battery is about 13.6v or so at full charge Maximum charging voltage is about 14.6-14.7v
The charge rate is usually no more than a few amps if the maximum charge voltage is observed.
The charge current might be 6A, then reduce to an amp or below during charging.
A 7AH PB should have a maximum charge rate of 700mah or so.
It's also useful to remember that an automotive battery can be used as a load during Lipo discharge to storage.
The PB will only accept up to about a 6A rate, due to the voltage limit for safe charging.
So, about 80-90 watts is the safe charge rate limit for the PB battery.
Last edited by chuckk2; 05-14-2016 at 01:25 AM.