AGM battery for older car?

[fsrph]

I have an older car, 2010 Forester. It always had a traditional lead-acid battery. Current battery is an EverStart Maxx from Walmart. Great battery, had it for 7-8 years but seeing signs of failure.

Want to replace it with same battery. Walmart out of stock for quite a while. They recommended an EverStart Platinum AGM battery.

Is that a good recommendation? I don't mind the higher cost but worried if my older charging system can charge an AGM battery properly. Thoughts appreciated.

Francis

[ClevrChico]

If you're looking for a lead acid battery, Home Depot beats Wal-Mart prices. If you're in the Midwest, Arnold Motor supply has good battery prices too.

[123]

Costco generally has good battery prices if you are a member.

If the OEM battery for your vehicle was a lead-acid battery I would stick with that. AGM batteries can have issues when placed in vehicles not originally designed for them.

[Doctor Rhythm]

I don't worry about brand and wouldn't pay for a premium model, especially in a car that you're likely ditching within 5 years. I buy whatever Costco sells, which in recent years has carried either an Interstate or Kirkland label. They also dispose of the old battery and have helped deal with warranty when a battery dies prematurely.

[123]

Google AI told me:

Yes, the 2010 Subaru Forester can come with an Absorbed Glass Mat (AGM) battery. AGM batteries are becoming the standard for modern cars

I would check the owner's manual or the manufacturer's website to verify however

[blortchplop]

I would check the owner's manual or the manufacturer's website to verify however

This article also recommends checking compatibility, which sounds like a good idea generally.

AGM batteries have different charging requirements compared to traditional lead-acid batteries. If the vehicle’s charging system is not compatible, it may not charge the AGM battery correctly.

[baconavocado]

I think if the battery manufacturer says the battery is ok for your car, you can use it.

I replaced the lead acid battery in our Prius with an AGM battery (Optima) and have had no issues. The original battery went for 12 years and I'm expecting the Optima to go at least that long.

[alfaspider]

I think if the battery manufacturer says the battery is ok for your car, you can use it.

I replaced the lead acid battery in our Prius with an AGM battery (Optima) and have had no issues. The original battery went for 12 years and I'm expecting the Optima to go at least that long.

I had an Optima Yellow top that only lasted 3 years after the OEM lead acid 5. Decided there was no good reason to spend extra for AGM. Some cars need AGM due to the placement of the battery.

[smitcat]

The correct charging map is different for conventional lead acid batteries and flat plate AGM's.
AGM batteries are easily damaged with an incorrect charging pattern which in turn shortens their life appreciably.

[enad]

I used the manufactures catalog (at the auto parts store) and looked up the model for a vehicle, bought it, installed it and it lasted 8 years. No issues whatsoever with charging.

[talzara]

Google AI told me:

Yes, the 2010 Subaru Forester can come with an Absorbed Glass Mat (AGM) battery. AGM batteries are becoming the standard for modern cars

I would check the owner's manual or the manufacturer's website to verify however

The 2010 Subaru Forester came with a 65D23L or 55D23L battery, both of which are flooded batteries.

Generative AI is designed to give you a plausible answer. It is not designed to give you the right answer.

Instead of asking the generative AI and then reading the manual to see if it's right, just start by reading the manual. It's a waste of time to ask the generative AI because you still have to read the manual.

[tibbitts]

I have an older car, 2010 Forester. It always had a traditional lead-acid battery. Current battery is an EverStart Maxx from Walmart. Great battery, had it for 7-8 years but seeing signs of failure.

Want to replace it with same battery. Walmart out of stock for quite a while. They recommended an EverStart Platinum AGM battery.

Is that a good recommendation? I don't mind the higher cost but worried if my older charging system can charge an AGM battery properly. Thoughts appreciated.

Francis

Why do you have to buy a battery at Walmart instead of anywhere else? Sam's? Costco? Or is this an especially rare battery?

What is the price difference for AGM vs. regular flooded? Are other sources substantially more expensive than Walmart?

Every brand's warranty seems to have degraded in recent years, so assumptions from the past may no longer hold true. I've had more battery problems lately than in previous decades.

[jmw]

No. Don't do it unless the original battery was AGM as well. You are making it worse for your car because it won't charge the AGM right. The recommendation to buy the AGM is bad.

[fsrph]

I have an older car, 2010 Forester. It always had a traditional lead-acid battery. Current battery is an EverStart Maxx from Walmart. Great battery, had it for 7-8 years but seeing signs of failure.

Want to replace it with same battery. Walmart out of stock for quite a while. They recommended an EverStart Platinum AGM battery.

Is that a good recommendation? I don't mind the higher cost but worried if my older charging system can charge an AGM battery properly. Thoughts appreciated.

Francis

Why do you have to buy a battery at Walmart instead of anywhere else? Sam's? Costco? Or is this an especially rare battery?

What is the price difference for AGM vs. regular flooded? Are other sources substantially more expensive than Walmart?

Every brand's warranty seems to have degraded in recent years, so assumptions from the past may no longer hold true. I've had more battery problems lately than in previous decades.

I have this Walmart group 35 flooded battery in both my cars. It has lasted over 7 years in both cars. It is $139 with 3 year warranty. Guy at WM recommended the AGM version at $179 with 4 year warranty.

I could buy a comparable battery at AutoZone or other car care chain but it's easily over $210. Closest Costco is 60 miles away.

I could buy the battery I want at a different Walmart 15 miles away. However they do not have a car service department and I would have to install the battery myself. Not sure how hard the install would be.

Francis

[dknightd]

No. Don't do it unless the original battery was AGM as well. You are making it worse for your car because it won't charge the AGM right. The recommendation to buy the AGM is bad.

On what do you base this opinion? AGM and "flooded" batteries are both lead-acid.
In My opinion an AGM battery is better in almost every way compared to a flooded lead-acid battery.

[smitcat]

No. Don't do it unless the original battery was AGM as well. You are making it worse for your car because it won't charge the AGM right. The recommendation to buy the AGM is bad.

On what do you base this opinion? AGM and "flooded" batteries are both lead-acid.
In My opinion an AGM battery is better in almost every way compared to a flooded lead-acid battery.

AGM batteries have different requirements for everyday charging while the engine is running. Some vehicles are equipped to supply the non AGM charging patterns only.

[dknightd]

I could buy the battery I want at a different Walmart 15 miles away. However they do not have a car service department and I would have to install the battery myself. Not sure how hard the install would be.

Francis

Normally replacing a car battery is pretty easy. But I do not know your car.
One bolt on each terminal. Disconnect the negative first, and reconnect it last.
One or two bolts on the tie down strap.
But the batteries are heavy, so that could be a problem.

Maybe Walmart would let you buy the battery at one store, and have it installed at the other store?

[dknightd]

AGM batteries have different requirements for everyday charging while the engine is running. Some vehicles are equipped to supply the non AGM charging patterns only.

Do you have a citation for that?

A "non AGM charging pattern" should be fine for an AGM battery.

[smitcat]

AGM batteries have different requirements for everyday charging while the engine is running. Some vehicles are equipped to supply the non AGM charging patterns only.

Do you have a citation for that?

A "non AGM charging pattern" should be fine for an AGM battery.

There are many here is one of them.....
https://www.power-sonic.com/blog/floode ... fferences/

All of our current battery chargers have the ability to select AGM or standard lead/acid - when choosing the lead acid setting for a charging pattern the AGM battery will always be left undercharged.

[dbr]

Charging an AGM battery using a battery charger for boats, etc. and running an AGM battery in a car with constant charging from the alternator would be two different things, would it not? Most of the advice I could find quickly seems to be talking about boat and other batteries taken out and charged on a battery charger from time to time. In this thread we are talking about AGM batteries installed in automobiles.

[smitcat]

Charging an AGM battery using a battery charger for boats, etc. and running an AGM battery in a car with constant charging from the alternator would be two different things, would it not? Most of the advice I could find quickly seems to be talking about boat and other batteries taken out and charged on a battery charger from time to time. In this thread we are talking about AGM batteries installed in automobiles.

In your current car what are the settings for the alternator (regulater and/or BCM) system?
Is it set to the lead acid profile? Is it set to the AGM profile? Is it a 'smart' system which can adapt to more than one system?

[dknightd]

There are many here is one of them.....
https://www.power-sonic.com/blog/floode ... fferences/

All of our current battery chargers have the ability to select AGM or standard lead/acid - when choosing the lead acid setting for a charging pattern the AGM battery will always be left undercharged.

Interesting read. Thanks for sharing. When was the last you put distilled water into your car battery?

Unfortunately that article did not specifically address what type of battery you should put in your car.

It seems to me, that on average AGM battery is superior. But they cost more. So it is a cost benefit analysis.

I agree, the ideal charging rate is different. An AGM can take more current. But does not respond well to extended over voltage. Since the AGM is sealed, and you cannot replace fluid. You can keep a flooded cell battery more fully charged, if you are willing to add more fluid.

When is the last time you added more water to your car battery? For me it has proble been more than 20 years!

[smitcat]

There are many here is one of them.....
https://www.power-sonic.com/blog/floode ... fferences/

All of our current battery chargers have the ability to select AGM or standard lead/acid - when choosing the lead acid setting for a charging pattern the AGM battery will always be left undercharged.

Interesting read. Thanks for sharing. When was the last you put distilled water into your car battery?

Unfortunately that article did not specifically address what type of battery you should put in your car.

It seems to me, that on average AGM battery is superior. But they cost more. So it is a cost benefit analysis.

I agree, the ideal charging rate is different. An AGM can take more current. But does not respond well to extended over voltage. Since the AGM is sealed, and you cannot replace fluid. You can keep a flooded cell battery more fully charged, if you are willing to add more fluid.

When is the last time you added more water to your car battery? For me it has proble been more than 20 years!

The last time I added distilled water to one of our car batteries was in Dec (checked twice a year in June and Dec).
The last time we added distilled water to the boat batteries was in Dec. as well.

If your current vehicle charging system is not capable (set for or adaptable) to the higher voltages required for AGM batteries they will never be charged near 100% which will contribute to a much shorter lifespan than if they were charged correctly.

AGM's can be superior in many applications but may not be cost effective. In general I find the payoff better when used in hot envireonments that have more numerous and deep use cycles (Florida and stop/start vehicle use). I find plain lead acid to be a very good choice in colder climates with less and/or lower use cycles (NY with standard start vechicles)

[dknightd]

The last time I added distilled water to one of our car batteries was in Dec (checked twice a year in June and Dec).
The last time we added distilled water to the boat batteries was in Dec. as well.

you win. I'm probably old and lazy.

[smitcat]

The last time I added distilled water to one of our car batteries was in Dec (checked twice a year in June and Dec).
The last time we added distilled water to the boat batteries was in Dec. as well.

you win. I'm probably old and lazy.

You are likely in a colder climate where checking water is not that important. And you likely do not use batteries which are cycled to a greater discharge. That can make a lot of difference.

[tibbitts]

Do all conventional flooded cell batteries have the ability to add water? In the modern era some conventional batteries I've owned have somewhat concealed openings to the cells but other ones... either they're very well hidden or I think I'd have to drill.

[smitcat]

Do all conventional flooded cell batteries have the ability to add water? In the modern era some conventional batteries I've owned have somewhat concealed openings to the cells but other ones... either they're very well hidden or I think I'd have to drill.

I do not know if they all have ability to add water.
Of the 20 or more we had in the past 10 years they all had access to add water. (conventional lead acid)

[dbr]

Charging an AGM battery using a battery charger for boats, etc. and running an AGM battery in a car with constant charging from the alternator would be two different things, would it not? Most of the advice I could find quickly seems to be talking about boat and other batteries taken out and charged on a battery charger from time to time. In this thread we are talking about AGM batteries installed in automobiles.

In your current car what are the settings for the alternator (regulater and/or BCM) system?
Is it set to the lead acid profile? Is it set to the AGM profile? Is it a 'smart' system which can adapt to more than one system?

I have no idea. One car I have is a Subaru Outback 2015 model. Do you know for that car? How would a person even find out this information?

Note I have had an AGM battery in that car the last four years that is a little on weak legs at -20F this year. Flooded batteries typically are about done at lowest temperatures in this climate after 3-4 years in use also.

Are bulletins like this relevant: https://static.nhtsa.gov/odi/tsbs/2017/ ... 3-9999.pdf

Here is some more conversation about AGM batteries and Subaru. https://www.subaruxvforum.com/threads/a ... ng.179423/

And here: https://www.subaruoutback.org/threads/s ... ng.550230/

This reading does not seem to give a clear cut answer.

One thing I can tell you is that I have a volt meter plugged into the cigarette lighter and anytime the car is started and running the reading is a steady 14.3-14.5V. When the engine is not running but the accessories are turned on the reading is typically 12.0-12.2 but can get less when very cold.

I have a thought that a lot of these issues can be related to cars that are driven very little and really need to be kept on a battery keeper between times, whatever the battery.

[smitcat]

In your current car what are the settings for the alternator (regulater and/or BCM) system?
Is it set to the lead acid profile? Is it set to the AGM profile? Is it a 'smart' system which can adapt to more than one system?

I have no idea. One car I have is a Subaru Outback 2015 model. Do you know for that car? How would a person even find out this information?

Note I have had an AGM battery in that car the last four years that is a little on weak legs at -20F this year. Flooded batteries typically are about done at lowest temperatures in this climate after 3-4 years in use also.

Are bulletins like this relevant: https://static.nhtsa.gov/odi/tsbs/2017/ ... 3-9999.pdf

Here is some more conversation about AGM batteries and Subaru. https://www.subaruxvforum.com/threads/a ... ng.179423/

And here: https://www.subaruoutback.org/threads/s ... ng.550230/

This reading does not seem to give a clear cut answer.

One thing I can tell you is that I have a volt meter plugged into the cigarette lighter and anytime the car is started and running the reading is a steady 14.3-14.5V. When the engine is not running but the accessories are turned on the reading is typically 12.0-12.2 but can get less when very cold.

I have a thought that a lot of these issues can be related to cars that are driven very little and really need to be kept on a battery keeper between times, whatever the battery.

I do not kmow about Subaru's - perhaps the owners manual or a Subaru owners forum.

Battery life (age it lasts) and battery capacity (% Ah compared to new) in low temps are not the same thing.
Battery life is affected greatly by the temperatures the battery is stored in - hot weather is not friendly to batteries (life is shortened).
Battery capacity is deminished in colder temps on all batteries (less Ah) - there are charts which describe battery capacity compared to ambient temps.

We had good results with regular flooded lead/acid batteries in the NE where it is cold - maybe 5-6 years life if taken good care. As a practice we often replaced batteries with another good (not expensive) lead acid battery before the 5th winter season as a pre-emtive measure to avoid failure.

Voltage measured at the battery at rest after the surface charge is removed is on good metric - battery voltage for lead acid will be different than for AGM. Measuring battery capacity with a simple & cheap battery tester is another good metric as long as you set the meter to the correct battery type (AGM/ lead acid) and adjust for AH , and adjust results for ambient temps.

For comparisons only we typically expect 7-9 seasons on the deep cycle lead acid batteries designed for that use in boats/RV's/stationary equipment.

IMHO ....4-5 years for a 'cheap' ($100-$125?)standard flooded lead acid starting battery in a typical car is a very good deal. Getting maybe another year or two for 45% more costs is not in our plans.
Just note - getting that 4-5 seasons on these batteries in a hot envireonment (90-100 ambient) is not in the cards, often life is maybe 1/2 of that.

[dbr]

Here is a post I found on a Subaru forum. Like anything else who knows if the author really knows what he is talking about:

"Yes, there are charging profile differences between EFB and AGM batteries. Primarily, AGMs like lots of amps at slightly lower absorption charging voltage.

My Subaru outputs 14.4VDC during charging. AGM battery charge voltage should be between 14.2-14.7 volts, so the Subaru alternator is well within spec. As long as you aren’t charging for extended periods at 15VDC+, you’re not going to have an issue. Also, car batteries are generally not deeply discharged, so they shouldn’t spend extended times at 15VDC+ to develop the problems you would expect by using improper voltage. The only time I see 15VDC is when I am coasting and the alternator goes into regenerative mode, but that is only for a few seconds when the voltage spikes, hardly enough time to cause off-gassing and sulfating of the battery plates."

Note the 14.4V datum is what I quoted before for the Outback.

[fsrph]

I decided against the AGM battery. Couldn't find concrete proof but didn't like the idea of charging the AGM with my cars 2010 charging system.

Local Walmart still didn't have the battery I wanted (EverStart MAXX 35, mfg East Penn, price=$139+tax). But the WM 12 miles away had only one in stock. This store doesn't do battery installs.

Drove there and bought the battery. Took to local WM and they installed it today. Worked out well.

Francis

[alfaspider]

I decided against the AGM battery. Couldn't find concrete proof but didn't like the idea of charging the AGM with my cars 2010 charging system.

Local Walmart still didn't have the battery I wanted (EverStart MAXX 35, mfg East Penn, price=$139+tax). But the WM 12 miles away had only one in stock. This store doesn't do battery installs.

Drove there and bought the battery. Took to local WM and they installed it today. Worked out well.

Francis

There were plenty of OEM AGM applications in 2010. It's really not new technology. But I also don't think AGM makes sense unless your application requires it. I actually run a Lithium Ion starter battery in my classic car, and it's actually an improvement over lead acid unlike the AGM it replaced, but the cost isn't justifiable for a daily driver (typically $500+ still).

[Padlin]

In the fwiw dept. I replaced the old SLA battery in my 2012 F150 with an Odyssey AGM, it struggles to stay charged. While trying to figure it out I noticed the manufacturer calls for a higher charging voltage than the truck produces, although it is fine for an SLA. I added a trickle charger under the hood as a work around, and plug it in occasionally as opposed to trashing a $300 battery.

Don’t know if cars that call for an AGM all put out a higher voltage or if it’s just this brand of battery that needs it. I asked my mechanic about it and he mentioned he’s run into AGM issues in older vehicles before but knew nothing about what I found.

[tibbitts]

I decided against the AGM battery. Couldn't find concrete proof but didn't like the idea of charging the AGM with my cars 2010 charging system.

Local Walmart still didn't have the battery I wanted (EverStart MAXX 35, mfg East Penn, price=$139+tax). But the WM 12 miles away had only one in stock. This store doesn't do battery installs.

Drove there and bought the battery. Took to local WM and they installed it today. Worked out well.

Francis

Thanks for following up and glad it worked out for you.

[dbr]

I decided against the AGM battery. Couldn't find concrete proof but didn't like the idea of charging the AGM with my cars 2010 charging system.

Local Walmart still didn't have the battery I wanted (EverStart MAXX 35, mfg East Penn, price=$139+tax). But the WM 12 miles away had only one in stock. This store doesn't do battery installs.

Drove there and bought the battery. Took to local WM and they installed it today. Worked out well.

Francis

I run AGM batteries in my 2002 car just fine. Plain vanilla charging systems are fine. The more problematic question for me is in newer cars that have odd ball programming schemes that are hard to understand, aka the Subaru don't charge on short drives fiasco (which my new car, a Subaru, is seemingly not saddled with, I guess, and also runs AGM batteries just fine).

[smitcat]

I decided against the AGM battery. Couldn't find concrete proof but didn't like the idea of charging the AGM with my cars 2010 charging system.

Local Walmart still didn't have the battery I wanted (EverStart MAXX 35, mfg East Penn, price=$139+tax). But the WM 12 miles away had only one in stock. This store doesn't do battery installs.

Drove there and bought the battery. Took to local WM and they installed it today. Worked out well.

Francis

I run AGM batteries in my 2002 car just fine. Plain vanilla charging systems are fine. The more problematic question for me is in newer cars that have odd ball programming schemes that are hard to understand, aka the Subaru don't charge on short drives fiasco (which my new car, a Subaru, is seemingly not saddled with, I guess, and also runs AGM batteries just fine).

After running an AGM battery in your 2002 car for extended times have you then checked the SOH/SOC on that battery?

[fleetwdl]

I have been using the Everstart Maxx for years. Recently replaced one with the Everstart AGM, and it works fine. It costs $30 more, but also has an additional year of free replacement. The new one works fine.

[dbr]

I run AGM batteries in my 2002 car just fine. Plain vanilla charging systems are fine. The more problematic question for me is in newer cars that have odd ball programming schemes that are hard to understand, aka the Subaru don't charge on short drives fiasco (which my new car, a Subaru, is seemingly not saddled with, I guess, and also runs AGM batteries just fine).

After running an AGM battery in your 2002 car for extended times have you then checked the SOH/SOC on that battery?

No, except after four years in this northern climate it finally no longer had the performance needed to be reliable at -20F and such. This is one of those cars that is used so little that keeping charge up is hard but we still survived without attaching a battery charger of any kind. Every now and then in cold weather I go out for a 1/2 hr or so drive on the Interstate.

[smitcat]

After running an AGM battery in your 2002 car for extended times have you then checked the SOH/SOC on that battery?

No, except after four years in this northern climate it finally no longer had the performance needed to be reliable at -20F and such. This is one of those cars that is used so little that keeping charge up is hard but we still survived without attaching a battery charger of any kind. Every now and then in cold weather I go out for a 1/2 hr or so drive on the Interstate.

It is always interesting to test the batteries after a run and also after they go to 'sleep' mode so all the extra drain is off the battery. Often that meand you need to lift the hood maybe 20 minutes ahead of time so the draw is minimized during testing. Even new batteries that would test at 100% will need to have the results adjusted for the battery temps at that time.
If I needed to have a battery reliable at -20F I would have the battery on a good maintainer and the car engine plugged into an engine heater.
For temps at about zero we used a CTEK for the battery and a Wolverine pan heater when we required reliability on our pickups.