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).
Analysis of P & R battery cell failure due to shorting, with a suggested design improvement for the separators.
| Identifier | ExFiles\Box 54\2\ Scan128 | |
| Date | 27th June 1928 | |
| EFC. {E. Fowler Clarke - Electrical Engineer} COPY 27.6.28. JC.109. FAILURE OF P & R CELLS. Two P & R cells have failed by shorting, one in S1 battery (154) and the other in SY battery (170). These faulty cells have been removed and an Exide cell from SY was put in S1 (No.6 cell) battery to complete same. On opening up these cells the short was found to be due to the stretching of the positive plates, causing them to come into contact with the negative bus bar. Fig. below:- [Diagram 1] SHADED PORTION SEPARATORS NEGATIVE BAR POSITIVE PLATES The negative plates and all separators were in good condition. The positive plates were very much deteriorated but would have lasted much longer if they had not been disturbed: they had also lost very little paste. The cells would have lasted much longer but for this one fault and to make some improvement I suggest that Messrs. P & R. {Sir Henry Royce} make the separators longer as per diagram below:- [Diagram 2] POSITIVE BAR SEPARATOR. NEGATIVE PLATE EFC {E. Fowler Clarke - Electrical Engineer} /G.JOHNSON. | ||