AGM battery on a non AGM car?

[Carmudgeon]

There is/was a member who wrote extensively on the topic of battery charging, and the needs of AGMs, in the past.

The technical differences can't be dismissed, but the practical differences are more open to question.

If one is willing to potentially sacrifice some of the capacity and service life of a higher cost battery, that's acceptable to some and not to others; at least the risk lies mostly with the battery, and not the vehicle. As repeatedly seen, "best practices" aren't necessarily followed, or followed consistently.

In practical terms, "NHAP" experiences and the lack of empirical testing make it hard to quantify what might have been sacrificed, also having to take into account usage factors.

I'm kind of having this debate now, for a vehicle where I know the bulk charging phase occurs at 13.8v, and the absorption a couple tenths lower.

That's within the bounds for a FLA battery, but not an AGM that wants to see 14.4v or higher.

 

[Ranger83]

My son has a 2001 Toyota 4Runner at school. We put in a very expensive AGM battery.

During the winter he had to drive back and forth two miles between two campuses. When it got cold he started to have to jump start the car a few times a week.

Don’t remember the peak charge voltage but the 4Runner guys said the stock voltage regulator did not allow high enough voltage to fully charge an AGM.

Purchased a conventional SLA battery and never had another problem. We put AGM in everything else.

 

[Snagglefoot]

For my area north of the 49 th, my Walmart Everstart Maxx batteries last more than 6 years. The AGM version have 4 year warranties but that doesn’t really appeal to me. I’m thinking folks are going for the 4 year warranty in areas where their batteries are failing early. Having said that my son runs a AGM in his 2010 Silverado. No issues.

 

[Snagglefoot]

Here is why consumers are picking up AGMs. Only Bitoggers know anything about voltage issues.

 

[Tomioka]

My son has a 2001 Toyota 4Runner at school. We put in a very expensive AGM battery.

During the winter he had to drive back and forth two miles between two campuses. When it got cold he started to have to jump start the car a few times a week.

Don’t remember the peak charge voltage but the 4Runner guys said the stock voltage regulator did not allow high enough voltage to fully charge an AGM.

Purchased a conventional SLA battery and never had another problem. We put AGM in everything else.

Some yota guys do a diode mod that replaces the 7.5A ALT-S to up the charging voltage.

Installed a voltagebooster pro to my 01 Tundra that ups the charging voltage .5v higher. 14.8V cold 14.2V hot.

 

[4wheeldog]

My son has a 2001 Toyota 4Runner at school. We put in a very expensive AGM battery.

During the winter he had to drive back and forth two miles between two campuses. When it got cold he started to have to jump start the car a few times a week.

Don’t remember the peak charge voltage but the 4Runner guys said the stock voltage regulator did not allow high enough voltage to fully charge an AGM.

Purchased a conventional SLA battery and never had another problem. We put AGM in everything else.

I have a 2000 4Runner since 2003. It has had both varieties of batteries without issues. However in the Winter here I charge the battery to full 2-3 times through the season, if I am only using it locally (Trips under10 miles).
I have always thought the battery doesn’t get adequate bulk charging. But it ALWAYS starts, so….

 

[Kalle.J]

I have a 2000 4Runner since 2003. It has had both varieties of batteries without issues. However in the Winter here I charge the battery to full 2-3 times through the season, if I am only using it locally (Trips under10 miles).
I have always thought the battery doesn’t get adequate bulk charging. But it ALWAYS starts, so….

That is a good idea.
As long as it has cold compensated alternator that works you should be fine. Well as long as you don't drive too many short trips.

 

[4wheeldog]

That is a good idea.
As long as it has cold compensated alternator that works you should be fine. Well as long as you don't drive too many short trips.

The cranking slows noticeably but it starts so easily that I just throw it on the charger when I notice. It is generally in the 60% charge range when I notice. Only happens in the 10-20s so global warming will make it a non issue in a few years.

 

[Ranger83]

I have a 2000 4Runner since 2003. It has had both varieties of batteries without issues. However in the Winter here I charge the battery to full 2-3 times through the season, if I am only using it locally (Trips under10 miles).
I have always thought the battery doesn’t get adequate bulk charging. But it ALWAYS starts, so….

We didn’t have an issue until my son drove it short distances for weeks in temps below 20° F. Nothing wrong with the battery, just wasn’t getting charged enough,