I charged my deep cycle battery for 12 hours, at the 10amp rate then for 2 hours at 2 amps. I put the meter on it and it read, 13.50. 5 hours later it read 12.53. There is nothing hooked up, just battery. Is it normal to lose 1 volt in 5 hours?
If you put the meter on it while the charger was still connected, then yes, your readings were normal. There will be elevated voltage while the battery is being charged and that will level out as the battery is actually charged. After you took it off the charger, the reading will drop. As long as it's over 12.1 or so, it's fine.
Hi, Mailman.<br /><br />What you are seeing is normal for a Deep Cycle battery.<br /><br />In addition to being a 12.6V battery, it is a huge capacitor. The extra 1V you see at the end of a charging cycle is a capacitive, or surface charge that will leak away in a few minutes to an hour or so. <br /><br />It is correct to read true battery voltage, 12.6v, after the surface charge has leaked away.<br /><br />No worries, Mate.
If you want to be accurate, battery voltage readings should be had not less than 24 hrs after charging AND the battery must be kept at 70 deg F. Personally, my attention span doesnt allow me to wait that long and temp is a guess.
I think the guys hit the nail on the head. If you check it in 48 hours and it has dropped another volt or more (without load) then it's time to replace it.
