Forum Discussion

dddire's avatar
dddire
Explorer
Nov 04, 2013

Maintenance chargers?

So now that a lot of us have our trailers put away for the season, I'm wondering what everyone uses for a battery maintainer? Of course this pertains to those of us who don't/can't stay connected to shore power all winter.

Last winter and going into this winter, I'm using a C-Tek 3300. Two seasons on my gp 24 and sg looks great.

On a somewhat related note, I use a Battery Tender Jr. on batteries for my motorcycle, snow blower and lawn tractor.

What are the rest of you folks using?
  • KJINTF's avatar
    KJINTF
    Explorer
    Nov 05, 2013
    "In climes like minnestoa and montana, ya gotta be careful when temps get to -40"

    Not seen -40c/f in western Montana in a VERY long long time..... Not sure if it has happened in the last 10K years west of the divide

    Maybe up by Pianotuna & south of him in North Dakota might see temps like that

    Best to keep the batteries in a heated garage either way
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Nov 05, 2013
    In climes like minnestoa and montana, ya gotta be careful when temps get to -40

    It would be best to maintain a battery at 14.4 volts at that frigid temperature.

    Under-maintained FLA will stratify eventually and that spells doom for the top area of the battery.
  • pkunk's avatar
    pkunk
    Explorer
    Nov 05, 2013
    "However, for you battery pros out there who live in colder environments, do FLA batteries that are kept fully charged freeze? Also, do AGM batteries - fully charged or not - ever freeze?"
    -20° here in winter and never had a frozen battery. We used to see -45° in Vermont in the '60s but when it was going to be that cold we brought the batteries in for the night so we could get the cars started in the morning.
  • pnichols's avatar
    pnichols
    Explorer II
    Nov 05, 2013
    My RV batteries require a float voltage range of 13.5V-13.8V, so I leave them in the rig and plugged into the stock converter during storage.

    However, for you battery pros out there who live in colder environments, do FLA batteries that are kept fully charged freeze? Also, do AGM batteries - fully charged or not - ever freeze?
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Nov 05, 2013
    pkunk wrote:
    MEXICOWANDERER wrote:
    I use an old transformer type 12 volt wall power supply. Rated 800ma. Balances out to 13.4 volts maintenance charge level. Cost me a pair of 3/8" ring terminals, some shrink tubing and solder. Most any half pound transformer-type "12 volt" 800ma power supply will end up doing the same with a single group 24 - 31 battery.
    Those 12v 'bricks' do a great job as a maintenance charger. I have 2 that I put clips on and use for all my off season batteries


    They can NOT break! Well, if you shove 180 volts into one while it's connected to a battery it may eventually overheat. But it's the most reliable single battery maintenance system I can think of. A BATTERY TENDER grade maintenance charger cannot possibly have this degree of INHERENT protection. BUT, exercising a periodic topping charge is still essential when storing batteries for four months or longer.
  • bob213's avatar
    bob213
    Explorer
    Nov 05, 2013
    I have a Redipulse on the trailer, a Schumaker on the boat and since the TV also goes into storage an cheap Walmart maintainer on it. All do their job and I have good batteries in the spring. Boat batteries are 8 years old now. Longest any boat batteries have ever lasted and the first I've used a maintainer on.
  • pkunk's avatar
    pkunk
    Explorer
    Nov 05, 2013
    MEXICOWANDERER wrote:
    I use an old transformer type 12 volt wall power supply. Rated 800ma. Balances out to 13.4 volts maintenance charge level. Cost me a pair of 3/8" ring terminals, some shrink tubing and solder. Most any half pound transformer-type "12 volt" 800ma power supply will end up doing the same with a single group 24 - 31 battery.
    Those 12v 'bricks' do a great job as a maintenance charger. I have 2 that I put clips on and use for all my off season batteries
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Nov 05, 2013
    I use an old transformer type 12 volt wall power supply. Rated 800ma. Balances out to 13.4 volts maintenance charge level. Cost me a pair of 3/8" ring terminals, some shrink tubing and solder. Most any half pound transformer-type "12 volt" 800ma power supply will end up doing the same with a single group 24 - 31 battery.
  • OH48Lt's avatar
    OH48Lt
    Explorer
    Nov 05, 2013
    I use Battery Tenders Jrs for the mower, Harley, and 2 ATV's. The batteries stay in those units and sit on trickle charge. The battery on the RV is removed, placed on wood or cardboard and not frozen, and put on a trickle charger. Schumacher makes a decent trickle charger also, have one of the older "brick" units that works well. Had a couple from Harbor Freight, they turned out to be junk.
  • EldIr's avatar
    EldIr
    Explorer
    Nov 05, 2013
    Shadow Catcher wrote:
    I have an AGM good for months, however even a conventional deep cycle is good for the winter as long as it is fully charged and there are no vampire loads, in other words pull the negative terminal.


    What he said. Remove battery, charge, put in basement. In spring, charge (minimal amount needed), put back in camper.

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