Deep Cycle Marine Batteries

Discussion in 'Survival & Sustenance Living Forum' started by therhino, Dec 26, 2012.

  1. therhino

    therhino New Member

    Anyone know much about deep cycle marine batteries?
    I have two in my basement that are supposed to run the battery back up for my sump pump, but they tend to fail reliably (lol). One battery is hooked up at a time to a continual trickle charger that runs off the house electric. When the power goes off and the sump well fills, the float on the backup triggers both the backup pump running off the marine battery, and a "siren" thing that sounds like a smoke detector. I call it the "hey, the house is flooding" alarm.

    I can't seem to keep these batteries charged right. The charger often throws a "charge fault" error, which I'm assuming means it's doing jack for the system.

    Do these marine batteries have a shelf life? Max number of charges? Does keeping them hooked to the charger at all times degrade them? Any way to tell if they're beyond useful life?
  2. Mongo

    Mongo Well-Known Member Supporter

    The trickle charger is probably not adequate to keep them charged. Assuming the batteries are good, I would recommend a charger that has an automatic cycle that will reduce the charge rate as the batteries charge up. You mentioned the batteries are in the basement. Are they protected from freezing?
    The batteries do have a shelf life. With the brand and model, you should be able to find the shelf life of your battery. There is usually a tag on top with the purchase month & year marked. The cells can be checked individually with a hydrometer. ( available at an auto supply.) It is important that the batteries are fully charged before checking with the hydrometer. With the batteries fully charged , the hydrometer with tell you if you have a bad cell. If you add water it must be distilled water.

  3. silverado113

    silverado113 New Member

    ^^^^^Yeah that pretty much covers it all :D
  4. JTJ

    JTJ Well-Known Member Supporter

    I pretty much gave up on 12v deep cycle in my RV. I had nothing but problems. I now use 2 6V golf cart batteries in series. Hold up much better. I would also suggest a smart charger available at RV supply store.
  5. c3shooter

    c3shooter Administrator Staff Member Admin Moderator Lifetime Supporter

    FWIW, if the batteries are sitting on a concrete floor, does not improve their life- I use wooden cribbing under mine. A deep cycle battery- as the name implies- is made to go from fully charged to fully discharged- battery in your car would be wrecked doing that. The amp/hr rating tells the tale on capacity- bigger number, more power. I use 115 amp hr batteries for the trolling motors on my fishing boat.

    Have you checked the fluid levels in batteries? If you have removable caps, take a look- with a flashlight- no matches or lighters, or you will learn about hydrogen gas. If liquid does not come higher than the plates, you got a problem.

    Your charger may also be part of the problem. A trickle charger is intended to maintain a battery, not to charge it fully. If you have typical lead/acid batteries, 3-4 yrs is a good life. Gel types 4-6 or so. And yes, you can haul them down to the local car parts place and have them run a load test on them. And the best charge for deep cycle is a slow charge.

    As said, a pair of golf car battteries and the CORRECT charger will do you more good. Suspect they will run the sump pump a lot longer than what you have now.
  6. therhino

    therhino New Member

    Thanks, all.
    The system was there when we bought the house, and the sellers were big "discount do-it-yourselfers". We didn't find that out until after we bought the house, and things started falling apart. I've found drywall screws used for some very odd uses in the house.
    I'll do some research on cart batteries, and give the charger another look as well.
    Now to see if I can get the EPA deposit back on these batteries without buying a new one...
  7. silverado113

    silverado113 New Member

    Yeah, I know what you mean. The previous owners of my house were big redneck ingenuity types.
  8. JSStryker

    JSStryker New Member

  9. rjd3282

    rjd3282 New Member

    Keep the batteries clean and dry. Dirt and moisture between the posts can drain a battery.
  10. trip

    trip New Member

    Battery's are self discharging. In other words they are constantly discharging themselves. I use a battery tender on my motorcycles and the batteries are 7 years old. They can vary the output to keep the batteries up. It sounds like your battery have sulfated. Might need new ones. As long as they are kept clean then it doesn't matter if they sit on concrete.
  11. hawaiifrank

    hawaiifrank New Member

    Some good ideas so far. I agree the permanent trickle charge is probably not a good idea unless it is the correct type that cannot overcharge your battery.

    One solution is to use two 24 hr timers in series. Set the first to be ON for 2 hrs per day. That allows the second timer to cycle around every 12 days. Set the second timer to be on for 2 hrs and the charger is plugged in to that. So every 12 days you get 2 hrs charge on the battery. Arrange the settings on each timer to give you the minimum amount of charging that will keep you charged fully without killing the batteries from overcharging.
  12. winds-of-change

    winds-of-change The Balota's Staff Member Admin Moderator Lifetime Supporter

    My house was maintained like that by the previous owners, too. :mad:
  13. hiwall

    hiwall Well-Known Member

    If you have a battery has sulfated or died it can sometimes be brought back to life. With Epson salt!!
    A lot of info on the net about fixing batteries with Epson salt(about $3 at walmart).