This reading is a little low but can't be properly evaluated without
also measuring the voltage right at the alternator with the engine
running. If the output right at the alternator is much higher, you have
voltage losses that you can address.

Also make sure all the loads are turned off during both measurements.

Mark

Kai Mei wrote:
> I'm reading 13.4v at the battery terminal engine and alt working. So
> ~2.23V for each cell.
>
> Can a car battery even charge to 100% like this? Let alone 2
> batteries, of mixed use (deep cycle, starting)
>
> Somewhat rhetorical, I know my batteries get some charge, but still
> seems less than optimal. With my slow starter I'm going to need all
> the help I can get.
>