Absorbent Glass Mat (AGM) Batteries

[jp1gt]

I check my batteries every once in a while to see what the static voltage is after sitting a few days. 2 batteries, one an optima and the others a diehard. they were about 12v static. I took the caps off the diehard and could see the "pouches" had no electrolyte on top of them. I filled them up and charged the battery. One mistake I made is that I put too much water in. I showed the depth of the cap. After letting it charge of a few days and letting the water burp out I checked the static voltage and it was only 12.4 which is normally not good. I dusted off the VAT 40 and it held 10.5@200amps for 10 seconds which is good for me. The optima you have to put a 3/4 inch schedule 40 PVC pipe siliconed to the 2 vents and fill with water. It goes in VERY slowly. Another thing you HAVE to trickle charge AGM batteries with a AGM mode on the charger. Feel free to add anything.

[Andy J]

I just changed out the AGM battery that came in my wife's 2014 GMC Acadia.It was still cranking well,but she was going on a long trip and I didn't want it to quit on her away from home.The AGM was a little more expensive,$200,but I believe it was worth it.We never had any trouble from that battery,never had to jump it off.As a matter of fact,I had never even looked at it until I changed it.

[JACK M]

What?

Water in AGM batteries?

Is this a joke or am I earning something new?

[TerryB]

3 minutes ago, JACK M said:

What?

Water in AGM batteries?

Is this a joke or am I earning something new?

That was my thought too Jack.  I’ve never looked at them for water content.  AGM batteries are now the preferred battery type for vehicles that experience lots of bouncing and shock like motorcycles, ATVs and similar machines.  They can be mounted on angles to fit in tight areas.  The battery in one of my motorcycles was mounted this way and the owners manual said an AGM battery was the only suitable type for this bike.

[Buffalowed Bill]

Gentlemen,

 

I have been using Optima batteries for decades, in some of my collector cars, both 6V and 12V. I'm not dissatisfied with either. In fact I preach the gospel of the battery and the technology. I could probably continue buying Optimas until I die, but my inquiring mind needs to know if there is any suitable competition from the newer iteration of AGM batteries, for both 6V and 12V collector cars that I should know about? 

[Bloo]

I doubt anything can quite touch an Optima of their "spiral" type. My first one was bought in 1995 and was stolen when it was 18 years old. It was still working fine. I have had several others, and they no longer have that sort of durability, but they are still worth getting in my opinion. The rectangular AGM batteries I have owned have not held up as well.

[plymouthcranbrook]

I have read and heard that when Optima production went out of the country(Mexico?) that quality standards have been allowed to lapse.  I have one in my Volare but it is only  a couple of years old I have had no problems. I put an AGM battery in my 2016 Traverse and have not looked at it again in the two years since. No problems especially  since the vehicle really isn’t used a lot.  Once or twice a week in winter and less in summer.

 

Edited June 18, 2022 by plymouthcranbrook (see edit history)

[jp1gt]

My post was to let people know that the AGM batteries CAN run out of water. 

[edinmass]

And they can leak. Been there done that.