Rapid voltage rise when charging
- charger shuts down early (incomplete charging)
A result of the battery charger
being fooled by the surface charge on sulphated battery plates. Higher charge
voltages are required to overcome internal resistance between battery and the
Charge acceptance is slower.
Explanation for this is the same
as the point above.
Rapid voltage drop under light
This is a result of two factors;
the first is that the battery contains a surface charge which is rapidly
depleted. The second is that a Sulphated battery has reduced surface area
between electrolyte and lead plates permitting limited ionic exchange.
In effect, the chemical reaction cannot keep up with demand.
Higher temperatures during
charge and discharge cycles
With a lower voltage available
from a more-Sulphated battery or cell within a battery array a load places
higher demand on that cell or battery than on the others. Using the electrical
power formula (Watts = Volts * Amps) when volts go down the Amps must go up to
provide the same power. More Amps (current) results in higher resistance
(heat) during discharge. Higher temperatures can accelerate battery
plate erosion which may lead to a flake of lead shorts a cell.
Specific gravity varies between
cells by 50 points or more
Cell to cell voltage variations
of 0.05 - 0.1 V.
Increased water consumption
A result of higher charge
voltages required to internal resistance the electrolyte breaks down into its
molecular components oxygen and hydrogen. Higher temperatures
charge and discharge temperatures cause evaporation.