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).
Chart recording of an electrical test, showing amperage over time with calculated values.
| Identifier | ExFiles\Box 54\1\ Scan333 | |
| Date | 5th March 1928 | |
| 7 8 9 10 11 12 5-3-28 171 SZ 103LBS 75 AH Average Amperes = 6.15 Hours = 4.5 Ampere hours = 27.6 .268 281-180w 5 4 3 2 1 0 | ||