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).
Battery discharge test chart for an Ediswan XSB 557-1-2 battery.
| Identifier | ExFiles\Box 52\4\ Scan060 | |
| Date | 20th June 1929 | |
| 20-6-29 221 Ediswan XSB 557-1-2 90ah 92ces. Average amperes 6.44 Hours -10.75 Ampere hours -69.1 75/ 1.80 v. {VIENNA} | ||