Replacement Batteries

[beenthere]

just get a recondition battery from interstate and have them load test in front of you there guaranteed for 6 months and cost like $50 i have used them in cars trucks and my old london aire

[Winemaker2]

Originally Posted by twinboat

Go with the AGM battery, if thats what you want to do, but don't replace your onboard charger.
It will do fine charging and maintaining a AGM battery.

The charger you mentioned is a 2 amp charger. That's great if your storing your RV, but woefully under powered for vacationing in the trailer, even with shore power.
The factory converter/charger has a 30 to 40 amp output. That covers the items your using and maintaining the battery charge.

A 2 amp charger will not keep up with the lights, fridge, water pump or heater amp draw. You'll just run the battery down during your trip.

All this talk about needing a different charger isn't true, in your situation.
Folks with large battery banks, dry camp often, and want fast recharge times, will want chargers specifictly designed for their battery banks.

Flooded and AGM battery charging profiles are close enough that a middle of the road converter/charger will work fine. AGM and flooded batteried are both lead acid batteries.

As usual I'm in agreement with twinboat.
I'm a big fan of AGMs and find Sam's Club Duracell made by East Penn a quality and affordable alternative. I have many in service in boat & MH and have had good life with them when treated properly.
East Penn has recently confirmed that there is no difference in deep cycle performance with AGMs like there is with FLA. Both their GC2s and GP 31 (& others) spec both AH as well as CCA for AGMs.
AGMs dont like to sit for extended periods at partial state of charge SOC. So about once/ week its helpful to make sure they are fully charged. Your maintainer will keep them at high SOC when stored if you can keep it plugged in. If not best to disconnect to prevent parasitic draw down.
I have recently installed a Balmar batty monitor and have been watching charging a a large AGM batty bank aboard my boat. What I'm seeing is even my multi stage charger set to AGM charge profile seems to switch prematurely to float stage when the bank is less than 100% SOC. By cycling my charger off /on it restarts in the bulk, then absorption stages before going to float again. The SOC increases with additional cycles. The learning is it takes some extra patience and cycles to get back to or as close as possible to 100% SOC. I may be overly banal about Betty care & monitoring but I've found the result is exceptional life.

[twinboat]

Originally Posted by Winemaker2

As usual I'm in agreement with twinboat.
I'm a big fan of AGMs and find Sam's Club Duracell made by East Penn a quality and affordable alternative. I have many in service in boat & MH and have had good life with them when treated properly.
East Penn has recently confirmed that there is no difference in deep cycle performance with AGMs like there is with FLA. Both their GC2s and GP 31 (& others) spec both AH as well as CCA for AGMs.
AGMs dont like to sit for extended periods at partial state of charge SOC. So about once/ week its helpful to make sure they are fully charged. Your maintainer will keep them at high SOC when stored if you can keep it plugged in. If not best to disconnect to prevent parasitic draw down.
I have recently installed a Balmar batty monitor and have been watching charging a a large AGM batty bank aboard my boat. What I'm seeing is even my multi stage charger set to AGM charge profile seems to switch prematurely to float stage when the bank is less than 100% SOC. By cycling my charger off /on it restarts in the bulk, then absorption stages before going to float again. The SOC increases with additional cycles. The learning is it takes some extra patience and cycles to get back to or as close as possible to 100% SOC. I may be overly banal about Betty care & monitoring but I've found the result is exceptional life.

You may have undersized cables from your charger to your batteries.
The charger senses the max voltage at its output, but due to voltage drop, that's not what's getting to the batteries.

[Winemaker2]

Originally Posted by twinboat

You may have undersized cables from your charger to your batteries.
The charger senses the max voltage at its output, but due to voltage drop, that's not what's getting to the batteries.

OK I can see where that might not provide a full charge but would it cause the bulk / absorption cycles to end prematurely and would initiating another cycle result in a higher SOC? Why? wouldn't the battys see the same reduced V?

I will take a closer look at wire size and run as well as V drop measurements.
The new monitor provides a good track of batty V and they eventually get fully charged after a few cycles of the charger.
Appreciate your insights.