From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The failure analysis of a P & R RR.11/1 battery after 28,476 miles.
| Identifier | ExFiles\Box 54\1\ Scan023 | |
| Date | 8th July 1925 | |
| X4617P EFC. COPY 8.7.25. JB.117. X.4617. RE FAILURE OF P & R RR.11/1 BATTERY+ This battery has two cells failed after having completed 28,476 miles on the load. Upon these cells being opened up the following points were observed. General. The cell to cell connections were somewhat corroded, but were quite tight and the electrical circuit O.K. The box was generally in good condition. No.3 cell. When withdrawing the elements from their container, the positive lug broke away from the plates, due to them having swollen and being tight. These plates had to be broken up to get them out and the paste was quite intact and firm, but the positive plate grids were very weak and easily broken. The negative plates were in good condition, as also were the ebonite separators, but the wood had worn rather thin and in one instance had eaten right through and the hole was clogged up with paste which shorted through the perforations in the ebonite separators. It was impossible to ascertain the amount of sediment which had collected owing to the broken pieces of positive plates in the bottom. No.6 cell. This cell was in a much worse condition than the other. The positive plates were the same but the negatives had loosened some of their pellets and pushed their way out, forcing themselves through the wood separators and consequently shorted through the perforations of the ebonite separators; this had occurred in every separator. The ebonite separators were showing no signs of wear. EFC/GJ. | ||