Avoid any water with Chlorine or minerals as this can
damage your batteries and are very dangerous. Avoid
splashing the battery acid on yourself, it is very corrosive.
Next, you will want to check the specific gravity of each cell
with a small instrument called a hygrometer. It is available
for about $7 from any auto parts store. Write this down and
keep a record of each cell as you go along.
Hook up your circuit to the battery. Careful to get the
positive and negative terminals correct or your DC fuse will
blow.
With the dimmer switch turned down all of the way, now
your DC volt meter will show the voltage of the battery.
Check your AC voltage. Adjust the voltage with the dimmer
until the DC volts is close to the AC volts. Be careful.
Maintain this charge for a week or two, and then check the
specific gravity again. Check the DC voltage with the
desulfator off the batteries.
You are aiming for voltages of –
Battery Rating Actual DC voltage
12 volts 13.6 volts
24 volts 27.2 volts
48 volts 54.4 volts
After a couple weeks (this could be 2 days to a month) you
will notice the Voltage and specific gravity remain the same.
Now you need to jolt the battery slightly with an equalization
charge.