battery testing

[firefighterbri]

I've been having trouble with my batteries staying charged after sitting for more than 6 -8 hours in this cold Michigan weather. I went to Sams club where I bought them to have them replaced. They tested them and said that they were good and tested at 1000 amps each but they are 850 amp batteries. could they be getting this higher reading because they didn't disconnect the batteries before testing, meaning that they are only at 500 amps each? I've been searching for anything drawing the batteries down and can't find anything. After leaving the charger on the batteries for more than 14 hours its still drawing 1 - 1.5 amps. could a bad battery continue to draw and not fully charge? sorry for all the questions but I've been battling this for several weeks now and I've read every post related to batteries that I can find and I can't seem to figuire it out.

Thanks

[jbeasts10]

I am pretty sure you cannot load test for a single battery ,while connected to another.I had one of my batteries that was bad and would show similar signs of what you are describing.

[layson]

did you test each battery separately? You can't test them while they are both hooked together...

my batteries showed they were fine when they tested them in the truck... now out of the truck one was 11 something volts and the other was 5 or 6..

[firefighterbri]

At the time the guy was doing the test I didn't think about it. It wasn't until after the at it dawned on me they were connected together and could give a false reading. I'm going back there tomorrow morning and have them recheck it with the batts disconnected. I'm thinking that I have at least one bad battery maybe both. Last night at work I couldn't find more than .25 amp draw and yet after sitting outside for around 6 hours it was dead after being on the charger all night.

[firefighterbri]

Well they checked them this morning and found both to be bad and replaced under warranty. We'll see how well it starts in the morning to see if they stay charged overnight. Thanks for everyone's help.

Brian

[samiam]

Might want to have your alternator checked for output. if the bats have been low for a while i think it can cause your alternator to die a little sooner if it's constantly working overtime. at least leave the new bats on a charger so you know you're starting off with fully charged bats and not putting the extra work on your alternator. i'd keep an eye on the bats over the next couple weeks to see if they are maintaining a charge - maybe something else, i.e. Glow Plug Relay, is shorted and slowly draining them. man electrical charging issues can be a PITA.