I want to make a solar charger for tool batteries. I’m thinking plug a standard AC dual 5 amp 20v battery charger into an inverter charged via a solar battery bank. Enough to charge four batteries during the day. That’s not in the budget so I’m going to start small with just one battery at a time (600watts?). Maybe two batteries a day if I can afford it.

Who here has built such a battery bank? What advice do you have? What handy online calculators do you recommend? Is there a spreadsheet available that is better than a calculator? In the past I would have looked for those myself but search engines are totally useless now. Would you rather have one big battery hooked up to the inverter or a bank of smaller batteries in series or parallel?

  • @Know_not_Scotty_does
    4•3 months ago

    Start with a 12v version of the tool battery charger instead, then you eliminate the need for the inverter. Just do a simple solar charge controller and battery for power.

    • FauxPseudo OP
      1•3 months ago

      The problems I have with that:

      1. most power tools do not have 12v chargers
      2. that limits the ability to charge multiple types of tool batteries without having a dedicated 12v charger for each brand of batteries. I want to be able to plug in a Makita, Hercules or DeWalt charger into the inverter so that I’m not brand locked.
      3. if the 12v too battery charger dies the whole system is useless. By plugging a standard AC charger into the inverter you can pull a backup charger you pick up at a pawn shop and just plug it in.
    • @mortalic
      1•3 months ago

      This won’t work for most tool chargers as they are 110-240v usually.

      • @Know_not_Scotty_does
        2•3 months ago

        I know for a fact Dewalt, Milwaukee, and Makita offer 12 volt versions of the chargers for their power tool batteries.

        • FauxPseudo OP
          1•3 months ago

          But not Hercules. Which is my default after my Makita stuff got stolen out of a work truck.