Holiday imperial 2001, Owner'S Manual, Page: 206 / 301

5. Freezing:
When the electrolyte freezes, ice formed dislodges the active material
from the plates. The battery case may crack and the electrolyte will leak out
when thawed. It is especially important to keep a battery at full charge in cold
weather to prevent freezing. The high specific gravity of a fully charged battery
does not freeze as easily. Never attempt to charge a frozen battery. Warm it up
first.
6. Corrosion:
Corrosion from spilled or splashed electrolyte form deposits that can
conduct electricity and can cause battery drain. Clean off all corrosion, espe-
cially around the battery terminals and on the top of the battery. Prevent
accumulation by coating the terminals and the exposed metal cable connectors
with high temperature grease.
7. Overcharging:
Overcharging rapidly converts water to gas and decreases the electrolyte’s
water content as the water evaporates. The electrolyte level drops and becomes
more acid in content. This subjects the plates to a higher concentration of sulfu-
ric acid and results in early battery failure.
NOTE: Any time you add more than one or two ounces
of distilled water per-cell per-thousand miles, check the
motorhome charging system for overcharging. Prolonged
overcharging generates excessive heat inside the battery,
which buckles the plates and destroys the battery. It is a fact
that over 50% of battery failures are caused by overcharg-
ing.
Why does the voltage on a discharged battery measure the same as a fully
charged battery until the loads are applied? The simple answer to this might go
as follows: A battery creates electrical power by converting energy from a
chemical reaction into electrical energy. As this reaction slows down, the bat-
tery voltage will drop. In a lead acid battery the electrolyte conductivity (how
well electrical current can flow through it) changes. The same current may be
available but the rate of the reaction decreases, causing a voltage drop.
Another way of looking at this is to use the analogy of a water pump
(a battery is an electric pump). The pressure in PSI (pounds per square inch)
that a pump delivers is like a battery’s voltage. The volume of water in GPM
(gallons per minute) is like the electrical current. Let’s look at a 12 PSI pump
with no loads (the pump is running but the outflow valve is turned off). The
pump will run and the internal pressure of the pump will build up to some point
higher than 12 PSI. When the valve is opened and the water is free to flow into
the loads, the pressure will drop to the rated output pressure of 12 PSI, but only
if the load is not too big. If the pump is designed to maintain 12 PSI at 15
GPM, and a load demanding 20 GPM is connected, the pump will not be able
to keep up and the pressure will get sucked down to a lower PSI. If the load is
Electrical Systems - House
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I M P E R I A L
8 • 2 0 6
Battery Voltage &
Current