I would’ve thought this answer would be really available. But after searching the forum and the Internet I can’t find a single post that tells me if I should use an AGM or regular type car battery. So what kind of battery goes in a 06 STR? AGM or regular old water an acid pipe battery?

 

I went with the oem style after reading some posts about some using agm and getting gremlins. Where you been buddy. Hope all is well

 

hi
the batteries are usually regular
but Ive used agm batteries in a few cars now and there far superior, worth spending the extra on a agm
they have more capacity and last longer and dont leak
cheers

 

i use the walmart everstart h8 in everything

 

Regular. They last up to 14 years, from reports here. 7 or 8, often.

AGM were maybe rare when the car was designed.

 

The S-type charging system does not put out adequate voltage for a long enough duration to fully charge an AGM battery. I believe the alternator only develops 15+ volts for roughly 5 minutes after a cold start and then the regulator rolls the voltage back to 13.5 volts when running.

 

2007 XKR
My first lead acid battery lasted three years. Seems normal...ish.
My next battery AGM lasted three years. ??
Is the reason why stated above?
Both lived on tenders.

 

I'd worry it's the wrong kind of tender.

My ordinary lead acid battery is 7+ years old (& I drive often enough so no tender). Previous lasted about the same.

 

Regular battery for the above reason.

 

Not meant as a hijack, but what brand/model of battery tender are you using? Is it labeled as a battery maintainer? Or is it really a trickle charger?

I have a vendetta against trickle chargers. They don't really have enough oomph for properly replenishing a battery that is run down, and if left connected will cook a battery. I wonder if that's what has happened to your batteries.

I've got a couple of vehicles in storage, and keep a Schumacher battery maintainer in use on each one. A proper battery maintainer can be left unattended indefinitely, unlike a trickle charger.

[/hijack mode off]

 

I got a conventional Interstate battery, group 49, if I remember right for my car a few years ago. When I was looking it up, it seems to fit a lot more farm equipment than cars. It was reasonably priced and seems to be doing fine. The original battery lasted 15 years, not too bad.

 

Northern Kali is a pretty mild climate, which helps significantly in longer battery life. I lived in the SF Bay area and had an Interstate battery last 12 years myself.

 

where did you read AGM batteries require >+15v to charge? Ive read numerous articles where they say an AGM should be charged using a bulk phase that is around 14.8v max and high current, then dropping to an absorption phase and then a float stage at around 13.6v. So that sounds pretty much like the way the alternator works: first theres the bulk phase then it drops eventually reach the 13.6v float.

I use an Iota DLS-55 battery charger with an AGM module that has these three charging phases built in. The charges automatically senses the battery voltage so it starts in the correct phase so it doesnt fry the battery but ensures the battery gets fully charged. It also prevents sulphorization by giving it a bulk charge after so many days.


AGM battery charging

 

My point was that upon the alternator's reversion to its normal charge rate [after 5 mins from cold start], the 13.5, or so, volts provided may not be enough to fully charge an AGM battery, for which the charging system was not designed...

I could have been clearer, perhaps.