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 showing the results of a battery discharge test after 8231 miles of use.
| Identifier | WestWitteringFiles\Q\February1927-March1927\ 67 | |
| Date | 21th February 1927 | |
| 21-2-27 159 5X 75 A.Hrs. 103 Lbs .675 AVERAGE AMPERES - 6.34 HOURS - 11.0 AMPERE HOURS - 69.7 1.80 w. AFTER 8231 MILES | ||