voltage of a fully charged deep cycle?

[bowman316]

The text book says that a fully charged battery will have a voltage of about 12.7 volts. But when mine if fully charged it will be at 14.5 volts. My starting battery is pushing 16 volts. Is this bad to charge the battery up this much? When It gets to 12 volts, it is dead, not fully charged.
So what voltage lets you know your battery is fully charged? because i know 12.7 is not right.

 

[j_martin]

Re: voltage of a fully charged deep cycle?

It would be about 12.7 volts with no load, or a light load. Charging, it should be 13.8 v or more. 14.5 is certainly realistic.

As a battery ages, sometimes it'll go up into the 15V range. 16 is a little high, assuming your gauge is accurate.

Many outboards have relatively small, unregulated charging systems. They will often push batteries up to 16V. Very little harm is done as long as you keep them up on water.

hope it helps
John

 

[JB]

Re: voltage of a fully charged deep cycle?

Once a battery is fully charged many take on a "capacitive" charge of a few more volts. That charge is quite weak and will disappear immediately with even a light load. It will drain away in a few hours even without any load.

Normal. No worries.