Rotted, Disintegrated Positives
1. Impurities. This has already been discussed. See page 76.
2. Overheating. The hot electrolyte dissolves the lead of the grids and that which is dissolved is never converted back to lead. Continued overheating wears out the grids, and the active material also, and the plate falls to pieces at the slightest pressure.
3. Age. Positives gradually disintegrate due to the prolonged action of the electrolyte on the grids, an occasional overheating, occasional use of impure water, etc.
Positives which are rotted and disintegrated are, of course, hopeless, and must be junked.