Which AGM batteries for solar?

[shade]

the germans were satisfied that was adequate protection to put the FLA in the same space as the occupants.

The Germans have done that before.



Actually, I heard there may have been another hydrogen source in that vehicle.

I just wanted an excuse to post that amazing photo. I'd use FLA batteries if LFP was off the table.

 

[dreadlocks]

I'll let you know if any dead nazi's fall out of my SUV lol..

 

[Alloy]

There are 2 things to look for when buying FLA batteries warranty and weight

 

[Alloy]

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.

Hydrogen disperses in air similar to CO. The only risk for small banks is ignition sources around the cells when charging. I've had cells pop (not explode) twice when disconnecitng battery chargers.

 

[dreadlocks]

earth cant even contain hydrogen, it all eventually makes its way out into space, and its like the smallest atoms so without a perfect vessel it tends to find its way out most containers considered airtight.

most people want their campers to breath, really any ventilation you'll find is adequate.. if its in a plastic box it'll catch any acid, but if you dont hook it up to dumb chargers and give your house bank decent charge sources its all been basically mitigated.. you wont be boiling away the liquids inside and what gets consumed will be very minimal, manageable and safe.

 

[Rbertalotto]

I'm not sure the linked Amazon example is even really AGM

What makes you think that? I've been using it for quite a while and have taken it down to 60% a number of times and it recharges just like every other AGM Deep Cycle battery I have.....So far it has been fantastic.

 

[Alloy]

What makes you think that? I've been using it for quite a while and have taken it down to 60% a number of times and it recharges just like every other AGM Deep Cycle battery I have.....So far it has been fantastic.

How is 60% determined?

 

[Alloy]

earth cant even contain hydrogen, it all eventually makes its way out into space, and its like the smallest atoms so without a perfect vessel it tends to find its way out most containers considered airtight.

most people want their campers to breath, really any ventilation you'll find is adequate.. if its in a plastic box it'll catch any acid, but if you dont hook it up to dumb chargers and give your house bank decent charge sources its all been basically mitigated.. you wont be boiling away the liquids inside and what gets consumed will be very minimal, manageable and safe.

FLA deep cyle need (not AGM) equalization charges which should be done with more caution/ventilation. I see people remove the caps which allows battery acid to cover the top of the batteries. It's better to leave the caps loose but in place.

 

[Alloy]

What defines disperse ?

Propane/Gasoline are heavy and do not disperse in air so it is possible to fill an open container from the bottom up with the gas/fumes.

 

[DaveInDenver]

What makes you think that? I've been using it for quite a while and have taken it down to 60% a number of times and it recharges just like every other AGM Deep Cycle battery I have.....So far it has been fantastic.

One clue is it's rated as 100 A-hr (which is specified at the C10 rate) and states a C/3 (30 A) charge current limit. The terms sealed lead acid (SLA), AGM, valve-regulated lead acid (VRLA), gel get mixed and confused. Whether it's gel is really neither here nor there and does have some advantages. But if it is you have to watch charge and discharge rates and temperature closer than with wet cells.

Traditional AGM SLA batteries (like typically Optima, Odyssey, X2, Northstar, etc.) used in a vehicle wouldn't have a C/3 limit. They can tolerate high current and high temperature better. A discharge of 2C or higher isn't harmful, which is why they are good for starting. On the flip side they can tolerate and potentially benefit from having C/2 or higher charge current. An Odyssey AGM can work up to 80°C without damage.

The opposite is true for gel, discharge and charge current and temperature have to be controlled to avoid damage since the gelled electrolyte is prone to drying. This happens from the heat caused when current exceeds the electrolyte's ability to dissipate it. That causes cracks to form, which is cumulative and permanent damage. This causes it's internal resistance to rise, which causes more heat and in turn leads to the demise of the battery.

The actual construction of the battery is important and finding reliable technical information on these Weize batteries is difficult. They are probably fine batteries but without knowing what the intended use and evironment (like their max ambient temperature, which seems to be 50°C) is and their discharge and charge profiles you have to make assumptions is the problem.

 

[Rbertalotto]

Thank you...Great explanation. I paid $159 for the battery. We shall see if it was a good investment or not.

 

[john61ct]

FLA deep cyle need (not AGM) equalization charges which should be done with more caution/ventilation.

Lifeline do have an equalization protocol, which is why many prefer them over Northstar or Odyssey.

Those Amazon batteries are definitely not proper deep cycling, nor are they AGM. SLA for sure, maybe VRLA, but only GEL and true AGM are good for deep cycling longevity.

They may be fine for you, but everything being equal won't last half as long as any of the makes I recommended, and the FLA longer than any of the AGM.

Your rig your choice, NP.

And FLA caps should be kept closed as delivered, unless you install recombining vent caps or an automated watering system

 

[john61ct]

How is 60% determined?

Using a decent BM / SoC meter, a given bank's at-rest voltages can be mapped to SoC%.

But the table changes as the bank wears out, so best is leaving the BM in place.

Some people just use voltage while not at rest, consider it "good enough", but that's very inaccurate.

A basic cheap coulometer is in between.

 

[Alloy]

And FLA caps should be kept closed as delivered, unless you install recombining vent caps or an automated watering system

One can keep the caps closed while equalizing if one knows the caps work but who tests the caps to know if they work?

 

[luthj]

Flooded lead acid caps are designed to vent. No need to loosen or remove, even during equalize (unless the MFG specifically states so).

There are catalytic recombinant caps which do a good job at reducing water loss. These are similar to whats inside a sealed lead battery, just without the pressure generating valve.

I also agree that a pair of GC2 deep cycle batteries is hard to beat.