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 recording an Exide battery performance test.
| Identifier | ExFiles\Box 54\2\ Scan192 | |
| Date | 18th July 1924 | |
| 51 18-7-24 146 Exide 6RR5/1/2 103 lbs 80 a.h. Average amperes = 6.63 Hours = 12.16 Ampere hours = 80.6 .783 1.80v CHART by MEGGER | ||