Question AGM Batteries

[turtyle]

Does anyone have a method to recharge AGM batteries that show zero charge? They were left out in the cold for more than 90 days.

 

[GTS225]

Well, AGM batteries are just lead-acid. It's the type of acid retention inside the case that makes a difference. My AGM in my T-bucket sits in an unheated garage over the winter, and I don't give it any special treatment.
I'd just try bringing it (them?) inside for a few days to thaw, then put a trickle charger on it. (2-4 amps) See what that'll do for you.

(Back story; In my early 20's, I worked in a Chrysler dealership's parts department. Every winter, we would get frozen batteries out of customer's cars that were replaced under warranty. I would take them to a bench in the back of the parts department, let them thaw for 2 days or so, then throw a trickle charger on them. I managed to bring back about 70% of them, and those were installed into used cars on the lot that needed batteries. Those were flooded lead-acid batteries though, so YMMV.)

Roger

 

[Rich W.]

I think that is mentioned in this article:

How To Maintain Batteries - Deep Cycle Battery Store

THE BASICS ON BATTERIES *Important Items Highlighted/Colored First things first. A 12-volt battery is not a 12-volt battery. Twelve volts is just a nominal, convenient term used to distinguish one battery from another. A fully-charged 12-volt battery, allowed to “rest” for a few hours (or days) with

deepcyclebatterystore.com

 

[turtyle]

Thanx Rich!
I will give your method a try...would sure hate to have to replace them given the cost.

 

[Jim]

I think that is mentioned in this article:

How To Maintain Batteries - Deep Cycle Battery Store

THE BASICS ON BATTERIES *Important Items Highlighted/Colored First things first. A 12-volt battery is not a 12-volt battery. Twelve volts is just a nominal, convenient term used to distinguish one battery from another. A fully-charged 12-volt battery, allowed to “rest” for a few hours (or days) with

deepcyclebatterystore.com

Very informative link.

 

[Rich W.]

Very informative link.

I think @TheLooks posted it a while ago. One of the better articles on batteries so I saved it and refer to it now and then.

 

[TheLooks]

I think @TheLooks posted it a while ago. One of the better articles on batteries so I saved it and refer to it now and then.

Yes, I have to refer to it also. With so many things to keep up with on other peoples rigs, details slowly slip away. I also have it bookmarked.