marine batteries?

Here in Mexico, it is hard to find deep cell batteries--AND they are expensive
.
I have an off-grid 150watt 12volt system in my mountain cabin, that works fine for weekends and has MARINE BATTERIES from Walmart for $55 each, and so far I have had to replace them after 5 years.

My question: From a cost perspective, is this a good option, or even cheaper car batteries (I know a guy who re-builds car batteries here), and I know NOT to let them discharge too much.

If deep cell is worthwhile, where can I find a decent price in Mexico?

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: marine batteries?

    You might not get that much more life from inexpensive Golf Cart batteries.

    It sounds like you are not cycling too deeply and getting the batteries properly/quickly recharged. And keeping them properly filled with distilled water.

    If your usage does not change (more loads, deeper cycling), it sounds like you have a good solution for the price.

    Paying 2-4x as much money for something that lasts 2x longer is not saving you money.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: marine batteries?

    Used electric forklift batteries could be an option. Warehouse managers will often replace the batts if 1 charge doesn't last for a full days shift - yet the batts may still have many years left in them for an off-grid cabin.
    A forklift's may be too big for your needs, but you could always split it and sell the other cells to friends or look for smaller batts in electric trolleys and other industrial equipment.
  • System2
    System2 Posts: 6,290 admin
    Re: marine batteries?

    Thanks Gentlemen, I guess the best situation here would be to re-build my own batteries--and then they could be of any type that I felt like using, no?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: marine batteries?

    Not many folks rebuild their own batteries... Do you have the information and materials/tools to this?

    If you had several forklift batteries--I guess you could take the cells apart and mix/match components to build out a good bank?

    Between the electrical, hydrogen gases, toxic lead, sulfuric acid/electrolytes, battery cases that may not be easy to open and reseal (smaller batteries)--A bit of care would need to be involved.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: marine batteries?

    i don't think i'd trust having a battery rebuilt. if those cheap walmart batteries are doing well for your loads (and it seems it is working out well by how long it lasted) then i'd suggest staying with what works as all other options would be more expensive or not as reliable imho. if you do opt for a larger capacity battery, then be sure you can properly supply the charge current it needs. we generally advise the rate to be between 5% and 13%.