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 order of two different 6-volt batteries for a direct comparison test.
| Identifier | ExFiles\Box 168b\3\ img089 | |
| Date | 26th September 1929 | |
| X 7535 E Roy.{Sir Henry Royce} from EFC. EFCA/AD26.9.29. X 7535P Will you please order from Messrs. Peto & Radford, one P & R 6-volt unit RRN11 battery in ebonite container. During the recent visit of their Messrs. Minchin and Pritchett certain minor modifications of internal design were arranged, and a new type of vent was shown to us which type we strongly approve. We are anxious that this battery now ordered should incorporate these items and also to include the fitting of full size ebonite separators. Will you please also order one Exide 6-volt unit in similar container type 3RR5-1KL again incorporating all the improvements mutally agreed as desirable with their Mr. Deen during his recent visit to our premises viz. greater distance between tops of positive plates and negative straps to avoid short circuiting due to stretching of positive plates, this has been in the past a common cause of first failure, also stronger grid to prevent growth. These two units will be run together as one battery throughout their life with a view to direct comparison of P & R and Exide batteries of an entirely up-to-date design. These two batteries to be delivered to us in fully initial charged condition. EFC. | ||