Battery: AGM vs. Flooded Cell

[Texas_Roadrunn1]

Our 5er, 2016 Continental Coach, currently has 4 6v Interstate “Maximum” Deep Cycle Batteries. I am planning to replace them, and am considering the GC2 Trojan T-105 w T-2 Technology (flooded cell), and the GC2 Trojan T-105 AGM w C-Max Technology
(sealed maintenance free). The obvious differences are ; maintenance free, and the higher cost for the AGM. Has anyone had experience with either or both of these batteries in terms of performance quality on a daily basis, and over time? If yes, is the higher price for the AGM version a good value vs.the (maintenance intensive) flooded cell option?

[babock]

AGMs also have a lower Peukerts constant so if you discharge them at higher rates, they actually have more capacity for people who do that. Since they have a lower impedance than FLA, they can also be charged faster.

[theoldwizard1]

Make sure your battery charging system(s) can handle AGMs. Slightly different charging voltages compared to flooded lead acid.

[DarkSkySeeker]

2oldman wrote:
AGMs hold a charge longer when sitting. And no watering or corrosion is really nice. Forget the money.. just cry once and get them. You'll never look back.

That's been my experience too with AGMs. I charge them at the end of a trip and months later when I prep for the next trip, I go to charge them and they are still good to go.

[2oldman]

AGMs hold a charge longer when sitting. And no watering or corrosion is really nice. Forget the money.. just cry once and get them. You'll never look back.

[full_mosey]

Price wise you can look into used AGMs. I am in a good place where we have a retailer that sells AGMs that are rotated out from industrial use on a regular cycle.

$75 for 110Ahs.

I recently got 4 x 155Ahs to build a 620AH bank at $428 OTD. Hardly more than the price of a single new retail AGM. They are dated Mar 2013. I charge with a 2200W/75A inverter/charger, plus 400W solar. In another system I have 2 of them dated Oct 2009. I expect the last 4 to last 10+ years as well.

Flooded batteries are not as much a worry over extensive maintenance; whereas the penalty of letting the plates run dry is catastrophic.

An ammeter is the key to knowing the SOC of AGM during charging.

HTH;
John

[Old_Days]

I like AGM batteries because you don't have to check the acid level. Living in a dry climate the acid in my batteries always evaporated.

[BFL13]

Not with those, but note the AGM requirement to get them full every so often (often as possible), which means charging at 14.4ish volts constant ( with no dropping to 13.6v before you get there like some converters will) to 0.5 amps per 100AH of battery. Now you can go to 13.6v.

So how are you going to observe that? I can see the amps taper down to that with my Trimetric monitor. Point being that going AGM also means getting an ammeter you can monitor.

You also need a charger that will hold the voltage at the right level until amps are down to spec.

[Lwiddis]

I’m happy with my wet T125s and the additional AHs they have.