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 recorder graph showing results from a battery discharge test.
| Identifier | ExFiles\Box 54\1\ Scan176 | |
| Date | 5th July 1930 | |
| 5-7-30 182 P+R RRII-3 75 a.h. 87 lbs. Average amperes = 6.43 Hours = 13.7 Ampere Hours = 88.1 .008 1.80w TRADE MARK | ||