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Fri Jul 10, 2020 4:12 pm

Does anyone here run an AGM starting battery in their Vanagon? Notice any benefits in how long the battery lasted vs flooded lead acid? Any issues with with alternator charging?

My battery recently croaked and I'm wondering if it'd be worth the investment since my bus sits around without being used for weeks/months at a time sometimes.

Fri Jul 10, 2020 4:36 pm

There are nearly zero benefits (In a stock configuration; mounting, venting and location) of an AGM vs flooded lead acid or even a SLA, they are all the same thing with some minor exceptions. If you’re just replacing a failed starting battery, buy the (normal) cheapest and most convenient flooded lead acid battery with the best warranty you can find easily. No need to google-fu this issue.

BK

Fri Jul 10, 2020 4:58 pm

AGM are much more tolerant of cold weather and long term storage.
I am also looking for one for the same reasons.

I have not tried too hard but surely there is something that will fit.

Fri Jul 10, 2020 6:03 pm

1988M5 wrote: There are nearly zero benefits (In a stock configuration; mounting, venting and location) of an AGM vs flooded lead acid or even a SLA, they are all the same thing with some minor exceptions. If you’re just replacing a failed starting battery, buy the (normal) cheapest and most convenient flooded lead acid battery with the best warranty you can find easily. No need to google-fu this issue.

BK

Thanks but I'm not really concerned about the mounting, venting or location. I have an '86 with a 1.9L Diesel and the battery fits in the rear just fine. I'm most interested in durability and the alternator charging issues (if any) people who have switched over have experienced.

I'm in the EU and car battery warranties are perhaps one of the things that makes me miss living in the States - no brand offers more than 2 years here. Random aside: I lived in Mountain View until last year and I miss the Cali sunshine sometimes :)

Fri Jul 10, 2020 10:27 pm

There are plenty of charging issues with agm batteries. In most cases the age of the van charging system doesn’t provide adequate voltage for proper charging of an agm. Research the charging profile and you’ll see. You can make the changes to your system but the expense isn’t worth it. I’m getting 6-7 years on standard batteries without issue. You’d be better off installing a battery tender to keep it topped off or a small solar trickle charger. I had an agm that died in 2 years and cost twice as much.

Fri Jul 10, 2020 11:09 pm

PDXWesty wrote: There are plenty of charging issues with agm batteries. In most cases the age of the van charging system doesn’t provide adequate voltage for proper charging of an agm. Research the charging profile and you’ll see. You can make the changes to your system but the expense isn’t worth it. I’m getting 6-7 years on standard batteries without issue. You’d be better off installing a battery tender to keep it topped off or a small solar trickle charger. I had an agm that died in 2 years and cost twice as much.

Thanks for the ideas, I do have solar panels on the roof and a full inverter and dc fuse system in the van so I could most likely do that.

Fri Jul 10, 2020 11:17 pm

loverofpeace wrote: My battery recently croaked and I'm wondering if it'd be worth the investment since my bus sits around without being used for weeks/months at a time sometimes.

The only way to maintain the life of an unused battery, regardless of type, is to keep it charged. When your bus sits around for weeks/months, you'll need to put it on a charger. My van has a charger on board and I plug it into AC nearly every day even though it gets driven most weeks.

My motorcycles don't get ridden that often but they're always on a charger and the batteries last years.

i know you didn't ask, but a $30 charger may get many more months of battery life than spending $100 more for an AGM battery.

$30 chargers...

Fri Jul 10, 2020 11:43 pm

jimf909 wrote: loverofpeace wrote: My battery recently croaked and I'm wondering if it'd be worth the investment since my bus sits around without being used for weeks/months at a time sometimes.

The only way to maintain the life of an unused battery, regardless of type, is to keep it charged. When your bus sits around for weeks/months, you'll need to put it on a charger. My van has a charger on board and I plug it into AC nearly every day even though it gets driven most weeks.

My motorcycles don't get ridden that often but they're always on a charger and the batteries last years.

i know you didn't ask, but a $30 charger may get many more months of battery life than spending $100 more for an AGM battery.

$30 chargers...

Perfect thank you! Case closed. Will buy a quality regular Flooded Lead Acid battery and a charger like yours :) hopefully my battery lasts longer than 3 years this time and doesn't give me any issues!

Sat Jul 11, 2020 3:13 am

Absolutely sage advice

Quote:
i know you didn't ask, but a $30 charger may get many more months of battery life than spending $100 more for an AGM battery.

Sat Jul 11, 2020 4:35 am

I know you've made your decision but I'll confirm it for you.

At my work, I was absolutely overrun with AGM batteries.
We had little electric boats, electric cars, electric golf carts, etc.
all told, at the peak almost 50 of them.

Almost all of these units were, and some still are, AGM batteries.
They have special profile chargers to satisfy their unique charging profiles.

I replaced batteries frequently. Three months of intense use, nine months of storage.
Storage was hard on them.

And then I have one (1) 1970’s era 36 volt golf cart with flooded 6 v batteries.
These batteries last year after year after year, 7-8 years usually. This is old heavy out dated technology.

As a result when I installed a house system in my camper I opted for two heavy and large 6 v golf cart batteries over any other storage system.
It is a decision I never regretted.

Now L-ion or LiFePo batteries are all the rage. Small, powerful, expensive and from what I'm reading.......... short lived in a camper situation.

Color me old, but give me a proven lead acid battery over any of the new technology I've seen to date.

Dave

Wed Aug 04, 2021 12:57 pm

OK, bringing this back to life. Looking for a final word on a good, powerful AGM starter battery in the stock location like the Odyssey 96R-600 (https://www.odysseybattery.com/products/odp-agm96r-battery-96r-600/).

I have 2 AGM house batteries (120aH and 50aH) and a SLA starter battery. I want to replace the SLA starter battery with a good quality AGM starter battery that will fit in the stock location (under the passenger seat) so I can rest peacefully knowing that I'm not damaging any of the batteries while they are joined via the Sure Power 1315A isolator while being charged by an onboard Iota battery charger or my solar setup.. I know there is a difference in charging profiles between the two types of batteries and I've been told before not to mix them.

Update: The reason for bringing this up now resulted from issues with my Sure Power 1315A. Although it had connected the two joined AGM's to the SLA starter (it clicked on its own and I also have the override switch), there was no current flowing to the SLA (AGM's -> 13.5v, SLA ~12.6). I just replaced the Sure Power 1315A today (I experienced the same behavior with the 1315A a couple yrs ago) and it connects as it should. I just can't help wondering if mixing the batteries is causing an issue somewhere.

Thu Aug 05, 2021 6:53 am

I wrote a post about this problem and my solution about 5 years ago:
How to safely run a flooded and AGM battery together
Because of my diesel engine, high elevation and cold temperatures in winter I insist on using an old-fashioned flooded battery for cranking. The trouble was that it is incompatible with the Odyssey AGM I have under the seat. The solution was to install a cheap eBay sourced programmable voltage controller. It kicks on the relay at about 13.5 volts and turns it off at some higher voltage so as not to overcharge the flooded battery. The challenge is to find a hysteresis setting for your system that doesn’t oscillate too much. That is, when the relay kicks on, the flooded battery pulls power, the voltage drops, and the relay kicks off. This cycle can repeat and be irritating if you have a noisy mechanical relay. The controller has a delay setting to prevent too much oscillation. The system has been running for 5 years without trouble.