ure to make temperature
corrections when taking hydrometer readings.) If the cell appears to
require an excessive amount of charge to restore it to condition, it
should be removed and taken to the repair shop for a separate charge.

If the cell has been allowed to operate in a reversed condition to
such an extent that the entire material of the negative plates has
turned brown, both positive and negative groups should be discarded.

Removing Impurities

Impurities, such as iron, salt (chlorine) or oil, may accidentally get
into a cell, due to careless handling of distilled water.

Iron is dissolved by sulphuric acid and the positive plates become
affected, change color (dirty yellow) and wear rapidly. The cell
becomes different from the rest in gravity, voltage and bubbling. The
remedy is to discard the electrolyte as soon as possible, flush the
plates and separators in several changes of water, thoroughly wash the
jar, use new electrolyte and then proceed in same manner as explained
for the treatment of badly sulphated cells, page 482.

Chlorine has an effect about as described for iron, and is evident by
the odor of chlorine gas. The remedy is the same as for iron.

Oil in the electrolyte, if allowed to get into the pores of the
plates, will fill them and lower the capacity very much. It affects
negative plates much more than positives. Probably the only remedy in
this case is new plates.

Impurities of any nature should be removed as quickly as possible.

Clearing High Resistance Short Circuits

A high resistance short is caused by the sediment falling from the
plates and lodging between the positive and negative lugs. As a rule
this condition will occur only when severe sulphation is present in
the plates.

A cell in this condition can be repaired by removing the element and
clearing the short circuit. The wood separators should then be
withdrawn and replaced by new ones. Lock pin insulating washers.
should be installed land the element reassembled in the jar and
charged to maximum gravity.

Clearing Lug Shorts

Short-circuited lugs are caused by excessive sulphation. The outside
negative bulges and the bottom lug bends over and touches the adjacent
positive lug. This can be remedied by removing both outside negative
plates and burning on new plates which have already been charged and
inserting lock pin insulating washers.

Putting Repaired Cells Back in Service

When placing a new