Hi 96,
12 hours of idling would do it.
Yes you can jumper to the 2 six volt batteries in series.
A Harbor freight volt meter will do--if you can leave the batteries "at rest" for 12 hoursl
96Tony wrote:
How long would the truck have to idle to goose the battery back up, say from 50% to 100%. Can I direct connect the cables up to the 2 6 volt batteries? (That question pretty much shows my electrical knowledge!)
Also, how can I get a frequent and accurate reading of what state of charge my battery is in. I'm trying to avoid the expensive meter that has been mentioned. Any suggestions on a decent reasonably-priced hand-held?