Am I supposed to fully charge my car battery or put it under maintenance with my NOCO G15000 charger? (battery not used for several months)?

I have a 12v lead acid battery  not used in several months that caused my battery charger to skip from  25% and move up to 75%. The battery itself did have some charge to power up its instruments and central locking unit, but not enough to turn the engine over. 

I simply hooked up my battery charger and selected 12V 15A to charge the battery. 

Also, would I be doing any damage if I replace the clamps from my battery charger with battery terminals? I believe terminals would give a better contact that in turn improves charging times.  . 


EDIT: There is no water inside the battery, can I use filtered water in it?

6 Answers

  • 2 weeks ago


  • ?
    Lv 6
    3 months ago

    Letting the water level go beneith the top of the plates allows that part of the plates to dry out. That part of the battery plate(s) is now shot. Never use tap water -- filtered or not. It as minerals which will ruin a lead-acid battery. Use only distilled water.

  • 3 months ago

    Just make sure the charger clamps are clean on the jaws and twist them onto the lead or copper cable clamps. At 12 volts, 15 amps charge it for 4 hours. When you take the battery cables off for more then half an hour you'll lose the idle speed memory in the PCM and your radio presets.

  • k w
    Lv 7
    3 months ago

    always keep the battery topped off, otherwise it may not fully charge and may leave you stranded.....

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  • Anonymous
    3 months ago

    Yeah changing the clamps would have no effect at all. You should have just checked the voltage before you started charging it. If the voltage was below 11.2 volts the battery has already been ruined to some degree. Lead acid batteries lose their charge over time and you're  supposed to keep the voltage over 12.2 volts for them to be reliable. 12.7-12.9 is fully  charged. They CAN be drained below 50% of their capacity but it's  bad for the battery. Draining them below 80% of their capacity is worse and fully draining them to 99% of their capacity can basically ruin them overnight.

  • Barry
    Lv 6
    3 months ago

    If your battery has stood idle for months it may be ruined. You should not charge it on high amps as that is likely to kill it stone dead. Select a low amperage up to 4 amps and leave it on for about a week. If the charge rate has not fallen at all you need to buy a new battery. A battery is good condition will show a zero charge rate after a day or two at the most. Changing the clips will have no effect at all.

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