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 Exide battery from chassis GYK-40.
| Identifier | ExFiles\Box 57\2\ Scan006 | |
| Date | 6th January 1927 guessed | |
| XJ5789 Exide battery from chassis GYK-40 (20HP) REGD TRADE MARK "MEGGER" Average amperes = 4.82 Hours = 9.7 Ampere hours = 46.7 | ||