Deep-Cycle Battery Monitoring Experiment

This is an example project where I might describe an experiment that I'm currently running at home.

A couple of years ago, I purchased a 12V deep-cycle battery to use in emergencies. I have a little inverter that I could hook up to it and maybe use it to power and appliance or something during the intermittent power outages we have here in the city.

I had this nagging feeling that I wasn't maintaining the battery properly. It's basically been hooked up to an intelligent charger since it was purchased and hasn't been put to use since. So last week (21-NOV-2011) I removed the battery from the charger and about twice a day I've been making DC voltage measurements using a simple digital multimeter.

At first I was convinced the battery was a loss. It quickly fell from 13.14V to 12.59V in about 24 hours. It's now a week later and it's still hovering at 12.53V.

I intend to let this go another 7 days, and then throw a load on it to see how well it stands up and what I can expect out of it.