Hot Ground???

buylow12 wrote:
I am using a panel from my solar controller. The 13.2 reading was at 2am after two weeks unplugged in a storage yard I assume the panels had brought it up to that point that day. Previously after a day of towing I'd get a reading of 14.4 which would then fall to a more normal 12.9 after being disconnected.


Tim Czarkowski
Totaltravelers.com

13.2 sounds right after a solar charge. The reason it wasn't 12.6 (full) is because they tend to hold a little extra for a little while after charging. Your charger was feeding it 13.2 volts before the sun went down and it stayed that way for a while. 14.4 would make sense after towing because that's what the alternator was sending it. This "extra" is called a surface charge.

The only way to get a true reading of the battery's charge level is get rid of the surface charge. Either wait 12-24 hours after fully charging or put it under a load of 20 amps for three minutes. Then you should see 12.6, which is considered full. It sounds to me like your battery is behaving normally.

As far as reading high amount of current between your negative battery terminal and ground. This also sounds normal. The negative post is where the elections come from. Electrons are negative, that's why that post is called negative. Negative and ground are not the same thing. The current is lower when you take a reading from the negative terminal to the negstive wire because there is now more resistance between the battery and ground (the chassis). MrWizard may be right, and the negative cable isn't connected properly to the chassis.

To sum it up, don't be alarmed if you test the battery after charging and it reads 13.2 or 14.4, and the next day it drops to 12.6.