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).
Cross-reference note regarding the 40/50 battery in two 6-volt units.
| Identifier | ExFiles\Box 168b\3\ img314 | |
| Date | 31th December 1930 | |
| X.7535. 31.12.30. For further matter relating to 40/50 battery in two 6-volt units see X.6054. X.6054.E. Exide X.6054.N. National | ||