Any Hands On Experience With Die Hard Gr 31 AGM?

MEXICOWANDERER wrote:
So one question is this. Anyone out there REGULARLY abuse their cyclable AGM batteries down to 60 - 70 percent depth of discharge (30% remaining) for years and years without problems?

Hi Mex',
I have three Odyssey 2150's which are identical (except for color) to the Group 31 DieHard Platinum. They are two years old and I have regularly discharged them down to 50-60% SOC according to the display on my Trimetric (read: large margin of error, but close enough) From what I can tell they are performing well and I haven't experienced any noticeable loss of capacity... I acknowledge that my use is a far cry from the 10-20% SOC that you are describing.

FWIW, EnerSys has a published a spec' of 400 discharges to 80&% DOD... Impressive if it is true.

I like that during times of heavy use (e.g. running the microwave), these AGM's exhibit much less voltage sag than my Trojan 6V FLA's did. Of course they can be charged very quickly too and mine are installed inside my camper in a space with minimal ventilation.

I do agree that AGM's are painfully expensive... and in terms of dollars per watt/hour, think they cost way more than even the high end FLA's do. But for me it is worth it because every summer I do extensive remote boondocking and my combination of solar & AGM's (+ occasional small generator use) allow me to live as if I'm on shore power. I consider the additional cost to be a convenience tax.

Cheers
-Mark

Helllo Mex wanderer. First gotta tell ya we are jealous of you being in Mexico this time of year. I hope someday we can do some late spring travel there. We still work in the summer and it will have to wait.

Re the AGM's, I can't give you a long term assessment of our AGM's as we haven't had them long enough. What I can tell you is our East Penn 8A31's (2 in Parallel) have served us well. They seem to take a charge quicker from our 320 watt array. I was concerned about the new Batts ability to provide large amounts of current to the microwave. Seems to be fine. Our little Class B/C has a tiny battery box and it was almost impossible to check the water and tougher to fill them. I think they are over priced at almost 300 bucks per pop but working at a dealer I am able to get a fairly good price. We have a gopower converter with pendant charging them and they seem to be happy. The solar controller is an MPPT type.

Hope you find what your looking for. If you have the chance, tip a Mezcal back for us. We miss Oaxaca. :)

Que te vaya bien amigo.

Almot wrote:

Lifeline is one of the best AGM, and costs more, and I recall on that boating blog a while ago - when it was free - that expected duration was 2-4 years if charged to no more than 85% SOC and equalized once a month. Equalization is called "conditioning" in their manuals. Pretty wide range, as you can see. There was no number of cycles given.

Thanks for remembering that info and posting it.

free radical wrote:

My brand new Lifeline AGM lasted exactly 8 months,then wouldnt hold charge anymore!
and Ive never discharged it more then 20% ,,,

its NOT the best imho and I would never get another one

Given your shallow discharges, this shouldn't have happened. Did you contact Lifeline, they're pretty good with sending out new batteries and providing technical support.

Almot wrote:
Mex, there is no "hype". Nobody ever said that AGM last longer given same abuse as flooded. Also, any battery will shorten its life A LOT, if routinely discharged to 30% SOC with occasional dips to 10%. When people pay 20-30% more for AGM than flooded, they are trying not to subject it to such conditions.

Lifeline is one of the best AGM, and costs more, and I recall on that boating blog a while ago - when it was free - that expected duration was 2-4 years if charged to no more than 85% SOC and equalized once a month. Equalization is called "conditioning" in their manuals. Pretty wide range, as you can see. There was no number of cycles given.

My brand new Lifeline AGM lasted exactly 8 months,then wouldnt hold charge anymore!
and Ive never discharged it more then 20% ,,,

its NOT the best imho and I would never get another one

Mex, there is no "hype". Nobody ever said that AGM last longer given same abuse as flooded. Also, any battery will shorten its life A LOT, if routinely discharged to 30% SOC with occasional dips to 10%. When people pay 20-30% more for AGM than flooded, they are trying not to subject it to such conditions.

Lifeline is one of the best AGM, and costs more, and I recall on that boating blog a while ago - when it was free - that expected duration was 2-4 years if charged to no more than 85% SOC and equalized once a month. Equalization is called "conditioning" in their manuals. Pretty wide range, as you can see. There was no number of cycles given.

I otta charge THEM for looking at it.

MEXICOWANDERER wrote:
Yeah, that's the point Mena, hype versus my wallet.

Lifeline's can be but it drastically reduces their life. Especially if this is done without their conditioning charging. I would reference the Morgan's Cloud blog for Lifeline's recommendations but that blog now requires money to view their content.

Yeah, that's the point Mena, hype versus my wallet.

As you well know, there are AGM's that claim they can be taken down to low DOD's but I have yet to read about anyone here doing that. Most seem to be on solar or kept well above 50%.