A batteries state of charge cannot be determined properly with
a Digital Multimeter. The measurement you get will not indicate if there is a weak or defective cell.
When removing a battery, always disconnect the negative
And put it back on last.
After removing the cables and hold down, use a good battery cart to
get the batteries out. It is easier and avoids spillage of electrolyte.
Once the batteries are out, inspect the box, clean all corrosion from
the area, along with the hold down bolt and channel, replace as necessary. HOLD DOWNS ARE IMPORTANT.
A solution of baking soda and water is good for cleaning battery and
Clean all the battery connections in the battery compartment.
Use Aerosolve 2 from ZEP, and a wire brush. Remove DDEC fuses before wire brushing the terminal strip at left of the
Clean the cable terminals good with a terminal cleaner.
Sweep out the battery box. Spray paint any areas that may look
Clean off the batteries and terminals. Use baking soda-water,
then pressure wash if you have that luxury. Check the electrolyte level in each battery. It should be over the
plates, do not overfill, leakage will result.
Put the batteries back in the coach, reverse how you took them out,
hook up the negative battery cable last.
Make sure you install the battery hold-down channel and bolt.
Otherwise the batteries will bounce and vibrate and be ruined.
There needs to be no battery movement during vehicle operation.
Vibration tends to shake the active materials out of a batteries plates,
crack the plates, seperate plates from posts, loosen terminals, and even crack the battery case.
The battery should remain in a fully charged state at
all times. This will prevent sulfation. A discharged battery should always be charged as soon as possible.
If the alternator is left to charge the drained batteries, it will
probably be damaged from overheating and shorten the alternator life.
Charge batteries with a low-rate slow charger.
Make sure the batteries are secured, cables tight and clean, caps on,
not hot, not over flowing or steaming, no corrosion, and full of electrolyte.
Regulator should be set to 27.2volts on an MC12 and 27.4 on
the rest. Check regulator output with all lights on, AC running.