Forum Discussion

ib516's avatar
ib516
Explorer II
Sep 19, 2013

Sweet deal on batteries

I was in Costco today, and saw they had their marine/deep cycle batteries on for about half price as it is the end of the RV season here in Canada.

I have two costco group 24s that I run in parallel in my 5er, I got them in 2007. Stickers on them say 5/07 (May 2007). Seems to me they don't last like they used to when boondocking. They are rated for 95Ah each and 140 min reserve capacity. When the RV goes into storage, I always remove them from the RV, wash them witha baking soda solution, bring them in the house, and charge them on a 2A automatic charger about once every 6 weeks. We do a lot of camping, and some is boondocking with the generator used to replenish the batteries, and some is where we have full hookups, and the RV stays plugged into shore power for a week or two at a time. I have had to add distilled water to the batteries -- about a new cup in each one to get them full again after a season of use. The RV has a simple parallax (sp?) Converter/Charger. I think I have taken good care of the batteries.

Back to the sweet deal...

Today, I got 2 group 27s for $49 each. 115Ah, 160 min reserve capacity, date stickers indicate 6/13 (June 2013). Had to buy them.

I guess what I'm wondering is this: Is 6 years about the life expectancy of an average RV battery given my usage, or did I replace them unnecessarily? I still have the old ones, don't know what to do with them. I might take them in to be testsed for the fun of it.

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25 Replies

  • KendallP's avatar
    KendallP
    Explorer
    Sep 23, 2013
    ib516 wrote:
    ...If not plugged in, I will cut off the batteries to prevent parasitic drain after they are back to 100%.

    That's good, but they will drain on their own. A float charger is ideal. I use the Harbor Freight cheapies. Find 'em on sale for 5 bucks or so now and then. I have half a dozen. All work well... so long as you don't let them accidentally become unplugged from AC. It will take weeks and probably months, but that will drain the bank also.

    The new versions run a little high on the voltage (about 14.14 on average,) but with a year or more, I have noted no loss in electrolyte, nor any heat buildup of any consequence.

    Our top resident battery guru/retired engineer, MEXICOWANDERER uses them also.

    Or spend 25 bucks and get a Battery Tender, BatteryMINDer or whatever floats your boat... or battery bank.
  • ib516's avatar
    ib516
    Explorer II
    Sep 23, 2013
    64thunderbolt wrote:

    OP, that's a smokin deal and put a cutoff switch on the trailer and that will stop them from discharging when stored.

    Great idea! I bought a cutoff switch at the battery place when I had the old ones tested. When we are at a CG with hook ups and plan to stay in one place for a while, I can wait a few days after setting up camp to ensure the batteries are at 100%, then disconnect them from the RVs electrical system. I will do the same once back at home:
    - If plugged into shore power in between trips to keep the fridge on, I will give them a day or two to get to full power, then disconnect them.
    - If not plugged in, I will cut off the batteries to prevent parasitic drain after they are back to 100%.
  • 64thunderbolt's avatar
    64thunderbolt
    Explorer II
    Sep 23, 2013
    the last set of 27's that went with the trailer when sold had been in 2 trailers. 1 failed @ 8 yrs in the Az heat.

    OP, that's a smokin deal and put a cutoff switch on the trailer and that will stop them from discharging when stored.

    I have 24's in my current rig with small solar maintainer. All is good. Just need to watch them and a little tlc goes a long way.
  • KendallP's avatar
    KendallP
    Explorer
    Sep 23, 2013
    Canadian Rainbirds wrote:
    ...However they have NEVER been under 80%.

    That's key.

    Lead Acid batteries can last a long, long time if you don't abuse 'em and give them just the least bit of care. It's not rocket surgery.
  • C_Schomer's avatar
    C_Schomer
    Explorer
    Sep 23, 2013
    I get 7-8 yrs out of 2 - 6v, stored plugged in with a charge wizard on my converter. I have solar now and I hope it does as well. Craig
  • mena661's avatar
    mena661
    Explorer
    Sep 23, 2013
    Canadian Rainbirds wrote:

    Mind you, I'm still using 6 2V 150AH float cells manufactured in 1984! They still run my 100 watt Ham station. However they have NEVER been under 80%.
    That's pretty impressive!!
  • Ron3rd's avatar
    Ron3rd
    Explorer III
    Sep 22, 2013
    That's a great deal; I paid about 78 bucks each (including tax) for the group 24s I got from Costco a while back.
  • Canadian_Rainbi's avatar
    Canadian_Rainbi
    Explorer
    Sep 22, 2013
    6 years with group 24s? You haven't been abusing them that is for sure. They don't owe you anything.

    Mind you, I'm still using 6 2V 150AH float cells manufactured in 1984! They still run my 100 watt Ham station. However they have NEVER been under 80%.
  • BFL13's avatar
    BFL13
    Explorer II
    Sep 22, 2013
    IMO you are doing fine with your batteries.

    Only thing wrong in the OP is the notion that there is an end to the RVing season in Canada. Vancouver Island is in Canada (Vancouver over on the Mainland is the start of "Back East" ) and RVing here is year round. We do see a lot of Alberta and Saskabush RVers here in the winter, who have given up on going to Mexico I guess.
  • ib516's avatar
    ib516
    Explorer II
    Sep 21, 2013
    KendallP wrote:

    I've been wondering their Amp hour rating. I was figuring more like 100. Where did you see the 115 figure? And did it notate "20 hour rate" or anything like that?

    Its on the sticker on each battery. In the OP, you can see it on the lower pic, bottom right number on the label of each. Top pic is the old units, you can see the "95" in the same position there.

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