AGM vs traditional flooded battery

[Argess]

I’ve done a little more research and as far as I’m concerned, all those “positive” attributes of an AGM battery are all unfortunately outweighed by the following “negative” comments I found on the net:

1/ https://www.repairsmith.com/i/blog/agm-vs-lead-acid/

Flooded lead acid batteries are much more tolerant to overcharging than AGM batteries. The sealed aspect of AGM batteries makes them more prone to thermal runaway, which can be triggered by overcharging. Even if you discount thermal runaway, overcharging will shorten an AGM battery’s lifespan faster. So, when charging an AGM battery, use a regulated battery charger to control the voltage and current going into the battery.

Note: Thermal runaway is when a battery generates too much heat than it can dissipate. The battery will dry out and melt, release toxic chemicals, and cause fires or explode in extreme cases. Nearby batteries will be affected and may result in a domino effect.

2/ https://batteryuniversity.com/articl...-glass-mat-agm

As with all gelled and sealed units, AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive.

AGM and other sealed batteries do not like heat and should be installed away from the engine compartment. Manufacturers recommend halting charge if the battery core reaches 49°C (120°F).

Yes, I’ve never heard of this happening, and I know many Cobra owners use an AGM battery, but I’m sort of a low risk fellow at times. Too bad though. I almost bought one.

[Sycraft]

That was my answer...... I work in the industry and deal with alot of batteries, do not even get me started on Optima batteries, I would never own one. Seen too many issues in applications.

Originally Posted by Argess

I’ve done a little more research and as far as I’m concerned, all those “positive” attributes of an AGM battery are all unfortunately outweighed by the following “negative” comments I found on the net:

1/ https://www.repairsmith.com/i/blog/agm-vs-lead-acid/

Flooded lead acid batteries are much more tolerant to overcharging than AGM batteries. The sealed aspect of AGM batteries makes them more prone to thermal runaway, which can be triggered by overcharging. Even if you discount thermal runaway, overcharging will shorten an AGM battery’s lifespan faster. So, when charging an AGM battery, use a regulated battery charger to control the voltage and current going into the battery.

Note: Thermal runaway is when a battery generates too much heat than it can dissipate. The battery will dry out and melt, release toxic chemicals, and cause fires or explode in extreme cases. Nearby batteries will be affected and may result in a domino effect.

2/ https://batteryuniversity.com/articl...-glass-mat-agm

As with all gelled and sealed units, AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive.

AGM and other sealed batteries do not like heat and should be installed away from the engine compartment. Manufacturers recommend halting charge if the battery core reaches 49°C (120°F).

Yes, I’ve never heard of this happening, and I know many Cobra owners use an AGM battery, but I’m sort of a low risk fellow at times. Too bad though. I almost bought one.

[patrickt]

My last two Interstate Mega-Tron batteries have both lasted 7 to 8 years in my ERA and probably would have lasted longer had I not broken down and replaced them. And I performed no maintenance on them whatsoever during all that time. Never even looked at the water levels. I would occasionally peek at the terminals to see if there was an abundance of that funky white stuff on them, but there was never enough to warrant doing anything so that's it. I wouldn't replace the battery in there with anything else.

June, 2024 -- see update below.