your car’s battery isn’t holding a charge or
otherwise is not up to par, you may be able to fix
it. The most common cause of degraded battery
performance in lead-acid batteries is sulfation,
which occurs when sulfur collects on the lead
plates in the battery, blocking the electric
current. It’s not difficult to recondition a car
battery at home. However, sulfation causes
irreversible corrosion of the lead plates, so this
process will work only three to five times.

Things You'll Need

Epsom salts (magnesium sulfate)
Distilled water
Plastic funnel
Safety goggles
Rubber gloves

Instructions
Test the battery to see if it is likely to respond
to reconditioning; it needs to register 12 volts
on a voltmeter. If it’s between 10 and 12 volts,
you may be able to restore the battery to full
function, but if it tests at less than 10 volts,
you’re probably wasting your time.
Heat a half quart of distilled water to 150
degrees F, and dissolve 7 or 8 oz. of Epsom salts
in the water.
Remove the battery cell caps. If you have a
sealed battery, find the “shadow plugs” that
cover openings to the battery cells--you’ll need
to drill through these.
Drain any fluid out of the battery and use a
plastic funnel to pour enough of the Epsom salt
solution in to fill each cell of the battery
properly.
Insert plastic plugs in the drill holes or replace
the battery caps and shake the battery to make
sure the Epsom salts solution is well distributed.
Recharge the battery on a slow charge for 24
hours and then re-install it in your car.

Tips & Warnings

Put the battery on the charger for three or four
nights to restore it to maximum capacity.
To minimize loss of performance, put car
batteries on a trickle charger if you won’t be
using them for several weeks or longer. A stored
battery gradually loses its charge, allowing
sulfur to form on the lead plates.
s Car batteries contain sulfuric acid, which is
among the most powerful of acid compounds.
Work only in a well-ventilated area and don’t
have open flames nearby. Wear safety goggles
and rubber gloves. If you get acid on your skin,
irrigate it with water immediately.
Don't use tap water because it contains
chemicals that will damage a battery.

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Does this work for inverter batteries too?