Group 65 AGM SLI Batteries

[Explorer2.0]

The more we read about AGM batteries the more confused we get! We understand the composition and advantages but what concerns us is the charging. Our 1995 Explorer has 23 year old charging technology and OBD1 diagnostics that we doubt could be reprogrammed for the AGM's requirements.

Anyone have any thoughts on the matter?

LG&KA - Team TARDIS


From: Three Misconceptions about AGM batteries | KnowYourParts

"AGM or gel cell battery replacement is the same as flooded battery replacement.

True and False. While the installation of the battery may be the same for the two battery styles, some vehicles require an extra step to tell the vehicle that the battery has been replaced. Newer vehicles have a Battery Sensor Module or similar systems. These systems require recalibration with a scan tool if the battery is replaced. If the system is not recalibrated, the alternator might overcharge the new battery and cause the battery to fail soon after replacement."

 

[koda2000]

Good question... I've never given this subject any thought and with the current high prices of even regular lead/acid batteries, I've never considered buying an AGM. I replace my lead/acid batteries every 5 years or so to avoid having problems. I have read that Optima batteries (are they AGM technology?) require a special battery charger for optimal recharging (not sure why) but if that's true you'd have to wonder how your alternator deals with them, but I haven't heard that the charging systems on newer vehicles is any different than it was 23 years ago, their electrical system demands are just much higher due to all the technology newer vehicles have.

There's no way in hell I'd spend $250 for an Optima battery for any of my 17/18 year old Explorers. IMO lead/acid technology is good enough. The last 3 Group 65 batteries I've replaced I got at Napa for around $90-$100 each. My '01 ST came with a Walmart battery in it and it's never given me any trouble to-date, though it's about 5 years old now.

 

[Explorer2.0]

We'd avoid Optima. It seems we're routinely getting coupons from the auto stores. Pep Boys has Bosch for a steal! Regularly $200 but with a $60 Promotion brings it down to a respectable $140. With our 20 year old core battery gathering dust in the garage it's a winner. 48 month warranty, too. Thanks for the reply.

Team TARDIS

 

[J_C]

Take internet info with a grain of salt, supposed tech sites (not just automotive) that try to give dumbed down answers instead of technical data, particularly on the internet where anyone can author anything and (extra-) especially if there is no author attribution or reader feedback allowed.

Automotive AGM batteries are designed to be drop in compatible with typical vehicle alternators as much as possible (it's kinda the point?). You're writing about charging but that's apples and oranges. A new battery is dropped into a vehicle with a charge already.

The alternator only provides a maintenance "charge" while the linked article author is vaguely referring to a complete low voltage to high voltage charge cycle. This is a typical way that people paid to produce web content, try to make up information by assuming things not mentioned to try to say "yer doin it wrong".

The vehicle should never have to have this done. The higher the battery charge, the lower the current from the alternator, but in an unusual case of excessive drain, yes if you put a wall AC powered battery charger on to charge it, better that it be ~10A or lower still, not a rapid charger.

However if you are worried about overcharging an AGM on a long trip at 14.4V, you could put a diode in series with the alternator to drop a fraction of a volt... just make sure it's current rated high enough, which generally requires heatsinking it too.

 

[Explorer2.0]

Thanks J-C!

But if it's on the internet it must be true, right? LOL!

Team TARDIS

 

[Explorer2.0]

We went with the AdvanceAuto AGM last year. 25% off coupon brought it down to 150 bucks! Five months... No issues!

Team TARDIS