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).
Price list for P & R Standard and Exide batteries for 40/50 and 20 HP models.
| Identifier | ExFiles\Box 54\2\ Scan051 | |
| Date | 10th December 1924 | |
| X4617 10.12.24. RE BATTERIES. X4617 X4642 The price of the 40/50 P & R Standard battery is £6.12.6. " " " Exide " " £6.14.6. " " " 20 HP.P & R Standard battery is £4.7.6. " " " Exide " " £4.8.6. EFC. {E. Fowler Clarke - Electrical Engineer} | ||