Did I get a bad battery

[TheThom]

Hello all,

I recently shelled out for a Concorde Sun Xtender 105 amp hour AGM battery to go in my camper. It's had some voltage drop problems. Initially I had it wired in and it dropped WAY low in the first 3 weeks I had it. Had an auto store charge it up and the voltage was fine for a 2 might trip (12.5V-12.1V). When I got home, I removed it and hooked it up to charge. I wasn't sure if my wiring was causing a leak to ground or I had a bad battery. I completely charged it up, then left the battery sitting and tested it and got the following results.

on June 12 the voltage was 13.14V On June 23 the voltage was 12.81V. The battery had nothing hooked up to it and was sitting on a piece of plywood on top of my table saw table.

Is that a normal drop for just 11 days (drop 0.3V)? Or did I get a bad battery? It was over $300 so it's getting returned if it was bad. Just wanted to get some opinions here first.

Thanks

[Dale M.]

Sounds pretty normal to me..... AGM batteries are a tiny bit less voltage than a flooded cell.... Just sitting and only .3 volts drop is probably just battery stabilizing after charge... Any reading with battery fresh off charge will be higher than "normal" and will take some time to stabilize out.....

The real test is how it maintains voltage level with a "load" of several hours...

Dale