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).
Graph chart recording data from a battery discharge test.
| Identifier | ExFiles\Box 54\1\ Scan253 | |
| Date | 2nd June 1927 | |
| 2-6-27 154 S1 75 a.h. 103 lbs. Average amperes = 6.32 Hours = 9.5 Ampere Hours = 60.0 .582 1.80w. | ||