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).
Graphical log from an electrical test showing ampere discharge over time.
| Identifier | ExFiles\Box 54\1\ Scan175 | |
| Date | 27th September 1929 | |
| 27-9-29 182 P&R RRII-3 97lbs. 75a.h. Average amperes = 6.35 Hours = 13.5 Ampere hours = 85.7 .885 1.80w | ||