Battery Questions

[Hans627]

I need new batteries. The existing group 24 Interstates were in the 2009 AS when purchased last year. There are a lot of choices in batteries, as you know. I'm leaning toward AGM because of ease of use (no need to check water levels). I don't want to change the battery box for golf cart batteries and we do little boon docking. The question is, which batteries to purchase.

I see some deep cycle AGM batteries are also used for starting, like in marine applications. Does having the starting capability have a negative impact on use in a travel trailer?

It seems as though Lifeline AGM batteries are highly respected but are more expensive. Are they better and if so why?

FWIW I will be upgrading my charger to a three stage charger before installing the new batteries.

Thank you for considering my questions and helping me with the learning curve!

[paiceman]

having worked with deep cycle batteries for years all I can suggest is you MUST take great care of your batteries and the previous owner(s) must have as well. If you are changing to three stage if it were me and taking care of batteries the way you have I'd simply replace with the same group 24 Interstates you had. Due to expense etc of lead the cells on the newer golf cart batteries are a little thinner so chances are they will not give you seven years but should last a good 4 years. I don't think you'd realize any significant benefit from AGMs. We have the AGMs in our 2015 with solar, so you are spot on they need nothing, but to me checking water would more than offset the additional cost of new AGMs over Interstates. You might look at an equivalent model in Trogan batteries we had good success with them in the 29,000 + golf cars we had in the market I was responsible for. By the way we considered four years life a bonus in the golf car industry, as they all started to die off at at the end of three years use.

Bud

[rwnash]

I went through the same decision process 5 years ago and ended up with two 12 volt lead/acid marine batteries, a low amp 3 stage charger and a battery isolation switch. That system has worked very well. The switch is a "marine" product that can select either battery separately, both together or turn everything off for storage.

I chose lead/acid batteries because they are cheaper and available everywhere. The "low amp" smart charger has enough capacity to charge the batteries and the lower charge rate is easier on them. (Batteries don't like either high charging or discharging currents.) As far as checking for water - I do it in the spring when getting the trailer ready. The smart chargers don't require as much water as the older systems.

Perhaps the best thing for good battery life is running them in separate banks when not connected to shore power. My wife and I boondock a lot and can stay out for well over a week if we are careful. I run one battery until it is down to about 12 volts and then switch to the other - I also start planning on when to return to civilization and recharge. (It helps that we converted to LED lights and turned off the "anti condensation" switch on the fridge.

Simple, relatively inexpensive and it works.

Whit Nash

[robi]

Hi! I have had Lifelines in my trailer since 2011. They perform like the day I bought them and work perfectly with my solar system. You are right about AGMs. Aside from not having to water them, they don't freeze, boil, or lose future charge capacity if you discharge them completely. I also used one in a previous trailer, if you boon dock, the performance improvement compared marine batteries is well worth the cost. I don't remember where I bought them. I checked the usual battery places and RV places (really frustrating as they didn't understand why i would want them). I googled AGM batteries and found them on line for about $200 less than in the stores, no shipping.

[Hans627]

Originally Posted by paiceman

having worked with deep cycle batteries for years all I can suggest is you MUST take great care of your batteries and the previous owner(s) must have as well. If you are changing to three stage if it were me and taking care of batteries the way you have I'd simply replace with the same group 24 Interstates you had. Due to expense etc of lead the cells on the newer golf cart batteries are a little thinner so chances are they will not give you seven years but should last a good 4 years. I don't think you'd realize any significant benefit from AGMs. We have the AGMs in our 2015 with solar, so you are spot on they need nothing, but to me checking water would more than offset the additional cost of new AGMs over Interstates. You might look at an equivalent model in Trogan batteries we had good success with them in the 29,000 + golf cars we had in the market I was responsible for. By the way we considered four years life a bonus in the golf car industry, as they all started to die off at at the end of three years use.

Bud

Thanks for your input Bud. I should have mentioned that the Interstates in my AS are the second generation having been replaced once by the previous owner. So they lasted about 3 years.

[lewster]

While charging any battery properly is of prime importance, most folks don't realize that battery life is directly related to how deeply you discharge them on a regular basis.

This applies to ANY TYPE of battery: liquid cell, AGM and even lithium.
The more deeply you discharge a battery, the fewer charge cycles you can expect!

For example, the Lifeline battery tech manual has a chart showing the anticipated number of charge cycles vs. the depth of discharge.

It shows about 1000 charge cycles at 50% DoD while listing 5000 charge cycles at a 10% DoD.

It's extremely important to FULLY recharge any lead based battery soon after any significant discharge to prevent sulfation.

The less you draw your batteries down, assuming proper charging, the longer you can expect them to last.

I have many Lifeline battery banks in use now that have far exceeded 5 years with about 1/3 of those in use over 10 years.

YMMV!!! ( and usually does)

.........and BTW, only low end battery manufacturers cheap out by reducing the amount of lead in their products. Premium producers like Lifeline maintain their battery structure regardless of the price of raw materials. They also offer a 5-year pro-rated replacement warranty, not 1 year that is common in the industry.

Lew Farber
RVIA/RVDA Nationally Certified Master Tech
ABYC Certified Master Marine Electrician
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center*AMS Lithium Batteries
Lifeline AGM Batteries**Magnum Inverters***Victron Energy Components
541-490-6357

[pebbrb05]

Has anyone with Airstream Interstate replaced Lifeline GPL-24T batteries with Duracell DURC 12-80P batteries from Batteries Plus?

[B4WEDI]

Originally Posted by pebbrb05

Has anyone with Airstream Interstate replaced Lifeline GPL-24T batteries with Duracell DURC 12-80P batteries from Batteries Plus?

I also wonder about the Duracell products.

I went to price Lifelines locally today and found the Duracell 8A -31 AGM's are the same width and height of our standard Interstate 27 batteries, but an inch longer and give you 210 minutes of reserve capacity @ 25A. The 20 hr. capacity was 105AH. The are warrantied for 30 months.

(whatever all that means..... )

They were also $100 dollars less (ea) than Lifeline too. ($229.00)

???

[Hans627]

Well maybe I don't need new batteries after all. I got a hydrometer and checked all the battery cells after a full charge with my new PD-4655 charger/converter. I found several cells that were in the white area (denoted as "Fair") with a 12.5 level. A few were in the green. But none in the red area.

So perhaps I'm good to go for a little while. Any thoughts?

[Rich W]

Originally Posted by Hans627

Well maybe I don't need new batteries after all. I got a hydrometer and checked all the battery cells after a full charge with my new PD-4655 charger/converter. I found several cells that were in the white area (denoted as "Fair") with a 12.5 level. A few were in the green. But none in the red area.

So perhaps I'm good to go for a little while. Any thoughts?

If you're reading green and white in the same battery then those cells will drag down the others. The battery is getting weak.

If you aren't boondocking I would say you're ok for this year but you should think about shopping. If you ARE going to boondock then you aren't going to get a lot out of them before going down to 12v.

[Hans627]

Originally Posted by richw46

If you're reading green and white in the same battery then those cells will drag down the others. The battery is getting weak.

If you aren't boondocking I would say you're ok for this year but you should think about shopping. If you ARE going to boondock then you aren't going to get a lot out of them before going down to 12v.

Yes some of the cells with the white readings (designated as in Fair condition) were in the battery as the cells with green readings. So we are on the borderline with these batteries. I'm checking them daily and keeping a log of the readings.

I have a few trips planned this summer but are not planning on doing any boondocking. So I think I'll make this set of batteries last for the summer and replace them before I head south this winter. I have too many other things on the go right now, especially since I discovered a water leak in the AS yesterday.

Thanks to all for the suggestions and input