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 log on graph paper recording amperage, hours, and weight.
| Identifier | ExFiles\Box 54\1\ Scan236 | |
| Date | 17th January 1927 | |
| SV 7 17-1-27 177 SV 75ah 103 lbs Average amperes = 6.30 Hours = 4.2 Ampere hours = 26.4 256 1.80w | ||