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).
Test chart graphing the performance and detailing the statistics of an S1 battery.
| Identifier | ExFiles\Box 54\1\ Scan186 | |
| Date | 6th July 1926 | |
| 6-7-26 154 SI S1 Battery 102 lbs 80 a.h. Average amperes = 6.48 Hours = 9.0 Ampere hours = 58.3 .571 1.80w RECD TRADE MARK T.M.E.C.C.L. | ||