Kohler K91 Owner's Manual page 157

SECTION
I
-
BATTERY
.
HOW IT WORKS
-
A
battery produces electricity as the result of a chemical
reaction.
The sulfuric acid in the electrolyte combines with the
positive and negative plates to form a new chemical compound
called lead sulfate.
The amount of sulfuric acid consumed by the plates is pro-
portional to the amount of electricity produced. Therefore,
the more electricity produced the less' sulfuric acid remains
in the electrolyte.
The gradual weakening of the electrolyte lets
us
measure,
with a hydrometer, the amount of unused acid in the water,
and thus how much potential energy is left.
i
F U L L Y C H A R G E D G O I N G
DOWN
Acid in water gives electrolyte As battery discharges, acid
specific gravity of
1.265.
begins to lodge in plates.
Specific gravity drops.
E N D / L I F E D I S C H A R G E D
Battery half discharged. Acid almost entirely in
More acid in plates, less in plates. leaving weak electro-
electrolyte. Starting lyte behind. Specific gravity
failure likely.
lower,
almost
that of water.
BATTERY CHEMISTRY
-1-