I just bought a new battery to replace one of my batteries that the post was coming out of. The other battery I left in bc it looked like a newer napa battery.
I was still getting some slow starts and I thought I'd try it today since it's 11 deg out and it would barely turn over and when dead. I jumped it for about 5 minutes and man if fired right up!
You think the new battery I just bought is ok still? Guess I'll be headed out to get another battery soon! freakin things are expensive!

 

If you have to replace one battery, you might as well replace them both. If the new one is in better shape (usually the case) than the one you did not replace, that one might draw down the new battery.

 

I have always been told to change both battery at the same time someone correct me if I have been told wrong.

 

That's what I do. If one battery is definitely "bad" and the other tests "good," I'll keep it as a spare for my travel trailer. When my truck needs one battery, she gets two, always.

 

I always replace batteries together . That is how I was taught .

 

This is what I have always been told and this is what I have always done. MY Father-N-law just replace one battery and it drags the starter now I told him he better get another battery but he has not got one I will probably get to put a new starter on it.LOL

 

I haven't had the new battery in more than a week so I'll go ahead and get another new one. thanks guys

 

The battery fine. The cold will drain the life right out of a weak battery. At 11* the batteries only can provide about 40% off there over all power. What most likely happen was the weak battery lost voltage and stool some from the new one. If one was at 12 volts and the other a 6. over a few days both would be come 9 volts. Then the weak one would drain quick leaving the new one dead. I'd put a charger or tender on it till u get another battery if u plan to start it in the cold am.

Another thing you guys can do to help your batteries is one a year swap them. The passenger side has more stress put on it. When u swap them like that sometimes you can get a longer life out of them.

 

thanks Doug!