AGM Batteries for Travel Trailer

Lifeline's cycle life chart is posted online in the Concorde AGM Manual. Gelled electrolyte batteries have FEW superior qualities over flooded 100% Pb sealed batteries. Specialty batteries for emergency exit lighting exceed cost benefit ratio with almost no superior qualities and nagging lifespan issues. The most vigorous promoters seem to be companies with the biggest investments into gelled manufacturing. The company with the greatest experience with gelled was Sonnenschein. Clearly superior lifespan but they surrendered at once to absorbed glass mat.

JimK-NY wrote:
First AGM batteries can indeed drop to 50% or so but I would not say that does not "hurt" them. The battery life expectancy is related to the depth of discharge and the number of discharge cycles. Less than 50% discharge would be recommended for a long life with many cycles.

From Trojan literature



A pair of 6V Trojan/Motive T105-AGM are spec'd at 216 AH. These are TRUE Deep Cycle batteries.

I see the OP has been reading the ads! 5x faster ! :) So with your 55 amp converter doing 55 amps on your 200AH of Flooded batts now, how are you going to get that 55 amp converter to put out 275 amps by swapping over to 200AH of AGMs ???? Tee hee, gottaluv advertising

First AGM batteries can indeed drop to 50% or so but I would not say that does not "hurt" them. The battery life expectancy is related to the depth of discharge and the number of discharge cycles. Less than 50% discharge would be recommended for a long life with many cycles.

Next don't count on AGM batteries charging very quickly. When my Lifeline AGMs are run down to even 70-80% of full charge, recharging takes hours, about 4 hours at 14.4 volts.

Not going to charge much faster unless you have large enough solar.
If you have a generator/converter going 90 amps at 14.4 volts then yes AGM is faster.

A week or so each time maybe three times yearly won't damage a good quality AGM. But where this fails is the batteries *must* thereupon be recharged at a steady 14.0 volts for 24 hours, then reverted to a temperature compensated float voltage.

Where is the origin of the Renology battery? What is their provenance? I do not not trust any made in China AGM that does not have hundreds of verified satisfied customers behind it. Under ratio AGM A/H to charger size systems can exist if the user is willing to have "rest and recuperation days" where total recharging is allowed. A Harbor Freight 2-cycle generator coupled to a 29 amp MEGAWATT power supply can work miracles for remote safe camping with AGM.

Some facts you may have missed
DEEP CYCLE be they AGM or Flooded wet can go to half full MARINE/deep cycle need to be about 3/4 or better. Starting better than 80% full.

They can be charged up to 5 times faster DEPENDING ON THE BRAND. Lifeline is the brand as I recall that likes to fast charge.. Not all brands recommend fast charging.