Using an AGM battery on an old car?

[FirstFord]

I know that AGM batteries use a different charging logic than conventional wet lead acid batteries, and thus, there are different settings on modern battery chargers to accommodate these charging needs.

My question is this: are there any negative consequences to installing an AGM battery in an older vehicle whose charging system is designed for a conventional wet lead acid battery?

Sponsored

 

[imnuts]

I put an AGM battery (two actually) in my '03 Audi I had before my truck. I replaced the OEM battery after it was about 10 years old and it almost didn't start one cold day. That first replacement was still going but starting to get week after about 7 years, so I put a second in that was still fine when I traded in the car. I'm sure there may have been downsides to it, but I never experienced any issues in that time. Car ran at about a constant 14.2V when on.

 

[lynskynbnd]

I run an AGM in my 1987 Jeep Wrangler. Works fine and powers the winch with no problems.

 

[FirstFord]

So you don't think the charging system designed for a conventional wet lead acid battery is shortening the life of the battery?

 

[Gros Ventre]

I believe there will be no big deals from such a replacement. While the system designed for an AGM Battery does do some things a bit differently, at the end of the day a lead acid battery is a lead acid battery. So put it in. The AGM type system does do some things differently, specifically an AGM battery has much lower internal resistance, is capable of higher burst currents, an has a lower resistance to overcharging. But the voltage regulators in older cars will provide what a Pb-PbSO4 battery needs.

 

[Buyer2021]

So you don't think the charging system designed for a conventional wet lead acid battery is shortening the life of the battery?

When the OE FLA battery in my 2005 F150 died I replaced it with a "4-year warranty" AGM; it lasted for 6 years, so no, it doesn't seem the 'wet-cell charging system' did it any harm or reduced its life in any meaningful way. I've been running AGMs in that truck since.

When I pulled the H6 AGM from my 2022 to install the H8 upgrade, that 'nearly new' H6 AGM found a home in my 2005, replacing its then 4-years old battery, you betchya! Yep, I turned in the 4 year old battery from the 2005 for the H8 core for the 2022.

 

[FirstFord]

When I pulled the H6 AGM from my 2022 to install the H8 upgrade, that 'nearly new' H6 AGM found a home in my 2005, replacing its then 4-years old battery, you betchya! Yep, I turned in the 4 year old battery from the 2005 for the H8 core for the 2022.

Bingo! We have a winner!

Yep, that's exactly what's going on. I just pulled a perfectly good Motocraft battery from my truck to replace it with an H8. Since the original truck battery is still perfectly good, I was looking for a home for it. I have an old car from the 1960's that I was considering putting it in (alternator: 55 Amps), but wasn't sure if that 60's charging system and the old truck AGM battery would play well together. Now I just need to see if it will physically fit....

 

[Jus Cruisin]

Optima in my 70 Chevelle.

Sponsored