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).
Battery discharge test graph comparing P&R cells with Exide cells.
| Identifier | ExFiles\Box 54\1\ Scan335 | |
| Date | 7th July 1925 | |
| 7 S4 8 7-7-25 157 S4 Battery 102 Cells. 80 A.h. The voltage of the P&R cells were much lower than the Exide cells whilst standing discharged. Average amperes: 6.46 Hours = 9.58 Ampere hours = 61.8 .606. 1.80w REGD TRADE MARK "MEGGER" | ||