AGM Battery Question

[4hackers]

I have a 2014 3100RL that needs a new battery. I would like to install one 12v or two 6v AGM batteries. I believe that I read somewhere that not all trailer chargers are compatible with AGM type batteries. Is that true? And if so, how do I figure out if mine will charge an AGM properly? If mine charger is adequate, does anyone have any recommendations on which brand batteries would be best?

A lot of questions, I know!

Thanks

[prndl]

AGM's do require a special charger.
AGM's are spendy. Two Duralast 6V GC batteries from Batteries+ will make you happy for less $$$.

[BuilderBob]

Interstate battery good 6v golf cart batteries also thats what I put in are's x4 and never
have any problems with battery power.

Bob & Carol
Tacoma WA
2017 352RL 2008 Dodge DRW 4x4 crew cab 6.7L

[mjammersc]

To know for sure if your trailers "battery charger" (it is part of the power center AC-DC converter that also does the charging) you'd need to look at the manual and data for the power center you have. A lot of Montanas have the Progressive Dynamic 4500 series power centers. Here is a link to the charge curves for their "charge wizard" https://www.progressivedyn.com/rv/ch...charge-profile


For AGMs, you'd need to see what the battery manufacturer recommends for charging (a lot of the store brands are hard to find details on) but Trojan, who is one of the better battery manufacturers (at least on led acid - no experience with their AGMs) publishes a good manual which is representative of most battery technologies. http://www.trojanbattery.com/pdf/Tro...UsersGuide.pdf


If you look at both sets of data, assuming that is your charge center, the charger circuit puts out a max of 14.4V and per Trojan (page 20), their AGMs need 14.4 for bulk charge phase and up to 14.7V for the absorption and finish phases. So in short, if you have this type of system, the charger and AGM battery charge voltages are compatible.


I'll save the discussion on if the charger in the power centers charge the batteries as well as they should for another day but from what I understand, the newer ones are much better than older ones though they still aren't ideal (compare the curves/voltages/etc and you'll see the centers could use more capability but are a good generic device)

[4hackers]

Thanks so much. This is exactly what I was looking for.

[jcurtis934]

I put in one group 31 agm 12vdc battery from west marine (made by the Pennsylvania company that also does decade batteries). Will put in another in parallel when I change out rv fridge for a residential one. I never boondock.

[Golferdave]

Originally Posted by BuilderBob

Interstate battery good 6v golf cart batteries also thats what I put in are's x4 and never
have any problems with battery power.

Bob & Carol
Tacoma WA
2017 352RL 2008 Dodge DRW 4x4 crew cab 6.7L

Hi Builder Bob: I am golfer Dave from Alberta. I have a 2013 Montana 3800RE new in 2012. Original Interstate 6 volt batteries. Batteries down in charge. Question ? How long do batteries last. We are full timers for the last 13 years. 8 years SOB and 5 Montana.
Thank you for any input.
Happy Trails.
GolferDave.

[Dam Worker]

I looked into AGM batteries when looking to upgrade from single 12 volt battery. I also heard about issues with converters but when I called the company that manufactured the converter in my 2016 Montana he assured me it would work great. If I remember correctly there were some settings that needed to be changed for the AGM BATTERIES. I did not go with them partly because of cost but if one does go bad not every battery store stocks them like they do with the regular deep cycle battery's. If you went with the AGM's they have a better cycle for use, meaning that you can draw them down farther without hurting them. In other words more useable energy before having to recharge. Lots of information out there if you want to take the time for research.

Tom Marty

[coachgrowl]

I just installed 2ea 100 AH lifep04 12 volt deep cycle batteries made in Reno by battle born batteries. $899 each plus $19 shipping. weight 29 lbs. removed 2 interstate batteries 43 lbs each. I will never have to change batteries again. Called BBB and they confirmed my 2017 310 RE will charge these batteries. Lead acid batteries must be recharged when they get to 50% capacity or they will start to die.

[TLightning]

coachgrowl...surely you didn't pay $899 per battery??? We have friends with a motor home and replaced the oem batteries with AGM 6volts. Paid $325 installed.

AGMs are great, put them in a forget them, plus no noxious gases.

[PNW Fireguy]

couchgrowl installed lithium oxide batteries. Very different from AGM. Apples and oranges. The price is not reflective or inline with AGM costs.

[CORattler]

Originally Posted by coachgrowl

I just installed 2ea 100 AH lifep04 12 volt deep cycle batteries made in Reno by battle born batteries. $899 each plus $19 shipping. weight 29 lbs. removed 2 interstate batteries 43 lbs each. I will never have to change batteries again. Called BBB and they confirmed my 2017 310 RE will charge these batteries. Lead acid batteries must be recharged when they get to 50% capacity or they will start to die.

WOW!
They must be made of gold. Hope they meet your expectations.

[coachgrowl]

I am pleased with the batteries. 5 year guarantee made in Reno. I never want to lift a battery again. Saved 26 lbs on weight for both batteries.

[CORattler]

Originally Posted by coachgrowl

I am pleased with the batteries. 5 year guarantee made in Reno. I never want to lift a battery again. Saved 26 lbs on weight for both batteries.

I can relate on battery weight consideration. My two 6 volt monsters are back breakers.