okie08vette

No it's not which is the best battery.
Are there advantages to a AGM type battery over the conventional type? I have to replace the battery in my 08 coupe. I have been using the OEM battery, replaced it once since 08 but I see lots of discussion about a AGM battery and just wondering what the difference is?

red430

The biggest difference is the AGM is sealed and will not leak like a conventional battery. It's important for a C6 because a good deal of the electronics and wiring harnesses are directly below the battery tray and if the battery spills it can become a big and expensive problem.

Garry in AZ

Absorbent Glass Mat batteries were invented in the 80's for military applications. The electrolyte is absorbed into fiberglass mat, and the battery can be made into various shapes. The absorbed electrolyte makes them spill proof, so they can be mounted in any angle, even upside down. They are also called recombinant batteries, because they never need to have water added. They have lower internal resistance, and are generally a bit lighter weight. AGM batteries charge much faster than a flooded battery, and they also retain a charge longer. They can be deep cycled more readily than a flooded battery and they tend to last longer, especially where a lot of vibration is normal.
AGM batteries are somewhat sensitive to overcharging, so while a battery tender is still a good idea, make sure it does not charge at higher than 14.4 volts.

Garry

jrose7004

A old mechanic that I used to know referred to them as "Maintenance impossible".

Bruze

I've never heard of them before. All I knew was the traditional wet cell, plus the newer gel cell.

Jimnc

They are very common in marine use since they can be discharged repeatedly without significant damage. I have four big ones on my boat.

Not So Fast

True that, my sons Conquest Deck has 2 of the big Odyssey batteries that have lasted over 10 years and they take a beating, over use to death.
Sadly they need to be replaced now, total bill, over $600
NSF






Sorry, had to throw in a shot of the business end LOL

_05C6_

AGM batteries are also popular with the motorcycle crowd.

jrose7004

I have them in my Sea Doo's.

blittle

The battery issue is a legitimate discussion...however, discernible differences will be hard to substantiate. ANY battery can be crap from the start....or....NOT! Bottom line is , with todays heavily electronics loaded cars....any battery is on thin ice at 5 yrs, and ANY battery ( top line ) you buy as a replacement will probably do another 5yrs just fine! The battery in my 2012 GS is the original and still starting the car as expected , but i will replace it this coming summer because a low voltage situation will cause today's electronic controlled cars simply to "go dead"......no warning!

RocketDawg

If you want to get an AGM battery, after all the posts above, and just FYI ... I bought one for my Vette almost 2 years ago and it's still going strong. I let the car sit sometimes for a couple of weeks and it's always strong. Regular batteries may do the same, but i'm just pointing out that this one has been really good. It also has a pretty high CCA rating, I think 680 (but can check if you'd like).

It's an AutoZone Platinum, and cost about $180.

Garry in AZ

Bruze, Lots of folks get AGM and Gel type batteries confused, because Gel came out first, and the name caught on as it related to a battery that could not spill. Then when AGM was introduced, the old name for an unspillable battery stuck. Sort of like everyone calls a tissue a "Kleenex" even if it's another brand.
There are actually very few Gel type batteries available for automotive use, because they have special charging requirements, and need modifications to a typical alternator setup to work.
The main difference is in the medium used to absorb the electrolyte. AGM batteries use a very fine fiberglass mesh material, and Gel batteries use a silica paste type material.
AGM batteries have higher cranking power for a given size battery, as well as faster charge times, and lower internal resistance. They also typically last longer than the Gel batteries.
AGM type outsells Gel by more than 100 to 1.
Hope that clears up some of the confusion.

Garry

okie08vette

Well just to follow up, I decided to go back with a AC Delco since the one in the car had warranty left I got the new replacement for 60.00.
Thanks for all the info on AGM batteries it was most helpful.

RocketDawg

I would have done the same. When I needed one, my Delco was out of warranty and I called my dealer and it was about $160, plus they wanted $80 to install it. It was July and I didn't want to fool with putting it in when it was so hot, not to mention my bad back that I don't want to risk damaging, so I went to AutoZone and they install free. Total cost of my AGM was less than Delco from the dealer.

Bruze

It does, thanks. Batteries are just one more type of technology that I haven't kept up with.

I replaced mine in July '14, when the time comes again I'll probably go with the AGM.

okie08vette

Full cost for the AC would have 124.00 while a AGM was 144.00 at NAPA so not much difference.

Bruze

Sounds like a no-brainer.