Which AGM batteries for solar?

Skinhyfish

Observer
My batteries on my Hallmark are at the 5yr mark and need upgrade. Been out of knowledge game for awhile and what is hip. Don’t want lithium because of all that I would have to upgrade. What brand do you all recommend these days?
 

john61ct

Adventurer
All those listed are fantastic choices for FLA, also add U.S. Battery.

And FLA is indeed (generally) better value than AGM.

But if AGM is truly needed

then Lifeline, Northstar and Odyssey are the top three mainstream makers in the NA market for quality deep cycling.

Call them for distribution local to you, shipping costs are silly high for lead.
 

Recommended books for Overlanding

Vehicle-dependent Expedition Guide
by Tom Sheppard
From $115.7
Into Africa
by Sam Manicom
From $23.88
Jupiters Travels: Four Years Around the World on a Triumph
by Ted Simon
From $17.54
Deep Survival: Who Lives, Who Dies, and Why
by Laurence Gonzales
From $9.99

dreadlocks

Well-known member
Flooded GC2 are best mobile boondocking battery, either cheap Costco/Sams deals for use and abuse or nice Trojan/Rolls for top shelf performance/quality.

The hip thing is becoming enlightened to AGM's limitations and how over-marketed they are, they have their place.. but for us that stops at being a starter battery.
 

john61ct

Adventurer
The FLA GC2s labeled Duracell are the best battery value by far on Earth.

Actually made by Deka/East Penn, deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

Just as good as Trojan IMO or at least very close.

Neither can hold a candle to Rolls / Surrette though, but you sure pay for the difference there.

The Costco ones are Interstate, made by Johnson, very much inferior quality to any of those mentioned so far.

But yes better than any 12V unit sold in auto stores or other big box retail.

The AGMs I mentioned are true deep cycling, could last 8+ years in daily use, just cost more, thus not as great value, Rolls can go 15+ years well coddled.
 

Rbertalotto

Explorer
I recently bought a couple AGM, 100Ah batteries from AMAZON. Been testing them extensively before the camping season begins. So far they are great. Can't beat the price ($179)

"Why AGM over wet cells????"......You're kidding, right... :)
 

DaveInDenver

Expedition Leader
"Why AGM over wet cells????"......You're kidding, right... :)
No, they aren't. The only advantage to AGM is being spill-proof they don't need to be mounted upright. Otherwise they cost more, need more careful charging, can't be serviced or recovered if abused. Places like Amazon like AGM since can they can be shipped easier, so buy FLA locally and use the savings for beer and gas. I do like them being sealed since it keeps the terminals from corroding but that's pure vanity and laziness.
 
Last edited:

DaveInDenver

Expedition Leader
Dont forget venting and potential to explode.
Not to say AGM cant do either, but that possibility is extremely lower than wet batteries.
True, FLA will typically vent during charging while AGM shouldn't normally or at least it will be minimal. The correct modifier (is it extremely lower or just significantly lower?) is probably a matter of personal preference but it's not impossible and so probably wise to take the same precautions. Such as using a battery box vented outside.
 

mobob

Member
First question: why AGM and not flooded? Specifically flooded golf cart batteries, Rolls Surrette, Trojan or Crown. If your heart is set on AGM then Lifeline.
No one mentioned the durability of AGM. I replaced three trolling motor batteries, high end wet cell that typically last two to three years in my bass boat, with AGM's almost six years ago and they are still running strong. Most of the degradation of the wet cells in a boat is due to vibration, much like a trailer, so I would think the AGM's would be a better long term option. I questioned the 30% uplift I paid at the time, but it was well worth it.

I currently run the Odyssey extreme AGM for every battery I replace, and I couldn’t be happier with them. I will be buying three more for my boat whenever the old AGM's let go.

My $.02 for what it’s worth.
 

john61ct

Adventurer
No, Deka makes great FLA and GEL, but their AGM are meh.

That Amazon unit is a joke, certainly not true deep cycling.

The three makes I mentioned are pricier but great value, if you really need AGM.

You need to be extra careful caring for any sealed model, no way to replace electrolyte level once lost to overcharging.
 

john61ct

Adventurer
Everything at this site wrt electrickery is gold, worth parsing closely.

 

DaveInDenver

Expedition Leader
That Amazon unit is a joke, certainly not true deep cycling.
I'm not sure the linked Amazon example is even really AGM. It's probably a gel tolerant of higher voltage. AGM is technically still a wet cell but the electrolyte has been fully absorbed in the glass mat to make it immobile while the electrolyte in a gel is mixed with a silica to achieve the thickening. AGM is similar to a gel in that they are valve-regulated. Gel and AGM are distinct types that aren't 100% interchangeable charging or discharging profiles or ability to tolerate heat and cold necessarily. You really need to follow the manufacturer's instruction for the actual battery model you have.
 

Recommended books for Overlanding

Vehicle-dependent Expedition Guide
by Tom Sheppard
From $115.7
The Essential Guide to Overland Travel in the United Stat...
by TeriAnn Wakeman
From $64.95
Overlanders' Handbook: Worldwide route and planning guide...
by Chris Scott
From $22.06
Morocco Overland: A Route & Planning Guide - Southern Mor...
by Chris Scott
From $21.1

john61ct

Adventurer
With sub par makers, often no detailed documentation is published, nor tech support staff available.

Good reasons to avoid that company's products.

All I mentioned has very technical staff readily responsive happy to discuss detailed questions.

With some the founders' family members handle customer calls themselves when things get technical.
 

dreadlocks

Well-known member
I recently bought a couple AGM, 100Ah batteries from AMAZON. Been testing them extensively before the camping season begins. So far they are great. Can't beat the price ($179)

"Why AGM over wet cells????"......You're kidding, right... :)
A pair of GC2's would beat the hell outta that.. over twice the capacity for roughly the same price, and it wont be some worthless no name fake deep cycle that'll be a boat anchor in 2yrs..

You've fallen into the pit of Marketing ****************.. paid more money, for less capacity.. and thinking you got more.. AGM's are not suitable house batteries for the vast majority of the audience here.. they need to be coddled and monitored constantly, which we cant provide it boondocking so they get abused and dont last any longer than FLA.

Offgassing concerns are much to do about nothing, yer lil 3A fridge is not gonna offgas a 230AH GC2 bank.. Just dont plug a dumb shop charger into one unattended and you'll be fine, its not like our rigs are space capsules, they couldn't contain hydrogen well enough to let it reach explosive concentrations even if you had heavy enough loads to generate a bit of hydrogen.. my vehicle has a FLA battery under the drivers seat in the cabin, all they did was put a DC charging system in it so they didnt overcharge the battery and apparently the germans were satisfied that was adequate protection to put the FLA in the same space as the occupants.

GC2's will also take vibrational loads quite well, the suspension on most golf carts is just the sidewall on the wheels and you really cant get more robust/thicker cell plates than you'll find in GC2's.. and the more robust the cells, the more abuse/deep cycling the'll shrug off.

For most overweight overlanders, AGM's place is as a lightweight, high output starter/winch battery.. most of us could start our vehicles no problem with a little Deka lawn mower battery if we needed to lose some weight and didnt have a winch to power.
 
Top