Morningstar, should I select Flooded battery?

[Guliver]

Morningstar SS-20L-12V 12Volt 20Amp DC Solar Controller with LVD
I have a 110Ah AGM battery.

I have it set to flooded ATM.

This is just a small system to run my radio shack, using a 130W mono panel.

Thanks Gulliver.

[Mike90250]

If you have a AGM battery, they are sealed, and are NOT flooded. Most morningstar gear has a AGM setting. Use it, or you will be replacing the battery very soon.

[Guliver]

A friend bought the battery for his caravan, the delivery driver must have dropped it as one end cell was cracked, he was sent a replacement and gave me the cracked battery, I had it plastic welded, remove the sealed cover, took it to a local battery wholesaler he topped it up for me and checked it, I then resealed the top and it has been running fine for about two years using a Ctek battery charger, I've just installed the solar gear in the last two weeks.

What is the difference between AGM and flooded? I understand AGM = Absorbed Glass Matt. Have I done the wrong thing topping up with standard battery acid?
As I said I've been using it for a couple of years without problem and the battery guy checked it out as good.

TIA

[SolarShadow]

It would be difficult to say the real cause of death for your battery. It was replaced because it was deemed no good from the start due to a cracked case, but at the same time you took it apart to add acid (They aren't supposed to be opened) and an AGM does not have a flooded liquid electrolyte that you can add acid to along with possible wrong charge settings. Those small PWM controllers by Morningstar aren't the best thing for an AGM battery.

[Sunking]

First you cannot add acid to a AGM battery. The electrolyte is not in a liquid form, it is in a silicon crystal form absorbed in a fiber glass mat. Both AGM and Flooded are the same chemistry, but from a operational point of view AGM operates at a slightly higher working voltage.

[Guliver]

I'm wondering if it is an AGM then, would an AGM have leaked as I described?

The battery has very low self discharge, after being left standing for a couple of months the ctek takes very little time to light the charged LED.

I guess I have no $$ in the battery, I'll keep an eye on it, I've got nothing to lose.

[PNjunction]

Yes, for the AGM, use the "flooded" setting. On that controller, that setting equates to 14.4v absorption (temperature compensated) per the manual. Most agm's use this as the absorption voltage, however there are some that like an even higher voltage up to 14.7v or so, and if that is the case, then perhaps you'll want to look into a controller that can set a higher voltage than 14.4v.

Morningstar's "sealed" is about 14.1v absorb, which is applicable to GEL types of sealed batteries, which most of us here do NOT recommend for solar.

About the only time I would consider the sealed setting with the simpler Morningstars with an agm, is if my solar application was mostly sitting in a float situation, so every day it would quickly absorb to 14.1v and then fall back to 13.8 float. For any application with any sort of appreciable discharge, then the flooded setting is what I set all mine to when using agm's.

Agm's like my Optimas and Odysseys get treated to a different controller that is adjustable to reach at least 14.7v.