Thread: Battery problem, battery testing and CCA vs RC

With the battery fully charged, I hooked up one of my old 100w driving lights which should draw very close to 8 amps, came back 3 1/2 hours later and the battery is down to 11.8V.

I suspected the battery was going to have a very low capacity and that just shows it.

Try the Battery Maintenance cycles I linked you to and after about a week, repeat your load test again.

Desulphation is a slow process but if the battery is recoverable ( most are ) then you will add years of use to that battery.