50amp deep cycle approx full voltage

A wealth of knowledge ,,,,, www.uuhome.de/william.darden/carfaq.htm

A fully charged battery will be 12.6 volts, when checking after the vehicle has been running always put a load across the battery for about 15 seconds to remove the float charge, by doing this you will get a accurite reading, if you don't you will have a reading of 12.8 to 13 volts.

Regards Richard

I'm no expert but I retreived this some time ago from a well respected battery site.
"These voltages are for batteries that have been at rest for 3 hours or more. Batteries that are being charged will be higher - the voltages while under charge will not tell you anything, you have to let the battery sit for a while. ..... It is important to realize that voltage measurements are only approximate. The best determination is to measure the specific gravity, but in many batteries this is difficult or impossible. "

State of Charge 12 Volt battery
100% 12.7
90% 12.5
80% 12.42
70% 12.32
60% 12.20
50% 12.06
40% 11.9
30% 11.75
20% 11.58
10% 11.31

However...
If the battery is an AGM or Gel cell the full charge voltage is approx 12.8-12.9

I have a 50 amp-hour Delco battery in my camper trailer - glass mat far as I know -(can hardly see it and have not had it out yet - but have seen the label with specs on it). When fully charged by the inbuilt 3.5A charger, the meter reads 13.8 volts (did get to 14 once) - once the charger is off and and the first minor current is taken (a light etc.), it settles back to the high twelves.

Hi Pixiemops

Yes as stated 12.7 to 12.9 at rest and depending on the type and temperature of the battery.



Regards

Derek.