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).
Technical report on car battery performance, discussing positive plate growth, cell design, and testing of composite batteries.
| Identifier | ExFiles\Box 164\2\ img006 | |
| Date | 1st April 1939 guessed | |
| Sheet 2. Positive plate growth generally occurs to some extent, and tends to be increased by undercharging, such as in the present instance, when the dynamo output was found to be insufficient. The smaller amount of deposit in the 11 plate cells is due to the fact that the same charging rate has a larger surface area of plate to work upon, and the density of gas evolution is therefore less than in the 9 plate cells. This feature would have been more marked if the charging rate had been higher. The negative plates were in excellent condition at the end of 3 years and 8 months service, as also were the separators and container. The results obtained with this composite battery are of considerable interest in view of the gradual changeover to thinner plates in Rolls Royce batteries, and to carry the matter a stage further Mr. Minchin has arranged to fit his car with another composite battery, this time using the latest .078" thick positive and negative plates in three of the cells, and for the remainder of the cells using the 3/32" thick plates. Both elements will be of the 11 plate size, because instead of increasing the number of plates per cell the height of the thin plates has been increased to compensate for the reduction in thickness, and also to give increased starting ability. AH. | ||