Battery draining/short?

[rockdogz]

Well I went out this morning and found both my batteries dead. I'm not sure, but I might have left the switch on to connect them together while the ignition is off. I have the painless switch that lets you combine the two either when the ignition is on or off.

Anyhow, I charged the main battery back up and was able to drive, and everything seemed ok. When I got back home, I went to investigate, and put a voltmeter on the auxillary battery. I could see the voltage drop... 10.75...10.74....10.73.... I thought maybe something was shorting, so I pulled off the cables. Well, the battery kept dropping voltage, with nothing else connected. It's an optima yellow top. This doesn't sound right, does it? Could the battery have a problem?