Follow up ? on battery charging

[surfdogg65]

I have two batteries that were drained. I have my camper at home plugged into my house. My question is about how long does it take to charge them up. Been plugged in for now about 4 hrs and it is at 1/3.

[Flybob]

It takes quite a while to charge two drained batteries. It will depend on the capacity of the batteries and how drained they are, but 4 hrs and 30% is not unusual. If the batteries are too deeply discharged, they may be toast and never really hold a charge. Add a battery tender or a disconnect switch for storage.

[rsdata]

do yourself a favor and buy a $5 to $10 meter at any hardware store or Harbor Freight or Wally world so that you can measure voltage of the batteries accurately...

Any battery that discharges to where it only measures 10 volts or less, will never hold a good charge again... A fully charged battery should measure from 12.6 to 13.2 volts

from a google source...

If the battery cannot reach higher than 10.5 volts when being charged, then the battery has a dead cell. If the battery is fully charged (according to the battery charger) but the voltage is 12.4 or less, the battery is sulfated

a sulphated battery can sometimes be reclaimed by the use of a specialty charger...

ALSO pop the caps on your battery and make sure to fill to the bottom of the rings with DISTILLED WATER ONLY, as all but sealed batteries will lose water and the capability to fully charge