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 battery plate condition and growth after 3 years and 8 months of service.
| Identifier | ExFiles\Box 164\2\ img005 | |
| Date | 1st December 1938 | |
| Condition after 3 years 8 months (December 1938) Capacity at 20 hour rate 62.0 amp. hrs. 62.0 amp. hrs. Weight of sediment per cell 2 ozs. 1 oz. Vertical growth of positive plates 1/8" 1/4" Horizontal growth of positive plates 3/16" 1/4" The active material of the positive plates was in very good condition after three years eight months service, and as the small quantity of sediment indicated, the loss by shedding was very small. Some of the positive grids had fractured, the extent to which this had occurred being approximately equal in the 9-plate and 11-plate elements. It is probable, however, that if the element had not been disturbed by being taken apart for examination the battery would have continued to function for a further period. With regard to the growth of the positive plates, it is noticeable that the 3/32" thick plates have increased in length and width to a greater extent than the 1/8" plates. This is to be attributed to the thinner grid, but as reasonable growth can take place without affecting adversely the performance of the battery, this feature has no particular significance. As already mentioned the amount of grid fracture was about equal in the two types of element. | ||