Battery charging

theghostjesustheghostjesus Registered Users Posts: 1
Good day and thanks for any help you can give me.

I bought a AGM Nautilus battery, Group 24 800/135/79

Unfortunately it discharged. Radio was left on and nothing left. I was wondering what type or brand of charger you recommend and what setting to use.

Thanks in advance.


  • BB.BB. Super Moderators, Administrators Posts: 30,642 admin
    You can start with any car charger and charge somewhere between 2 and 8 amps (ideally). Monitor and make sure that you do not charge over 14.4 volts.

    Or, purchase a charger for sealed/AGM/GEL batteries (they typically will charge to a maximum of ~14.2 to 14.4 volts. Standard car chargers are typically designed to charge to a higher voltage (and will damage sealed batteries).

    With sealed batteries, if you hear any noise (rumbling, hissing, venting), stop charging immediately.

    Most rechargeable chemistries do not like being taken to "dead". There is a good chance that your battery has lost much of its life.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivormcgivor Solar Expert Posts: 3,428 ✭✭✭✭✭
    By stating nothing, what voltage remains? Generally  when a 12V battery is completely discharged, below 10V, it's usually too late to consider recharging, the damage is terminal. Having said that I recently recovered a motorcycle battery at 10.2V with a high current charger 60A initially to get things happening, then reduced current to 1A over 5 hours. If however the voltage is below ~10V there is little hope of a full recovery. My opinions others may differ.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
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