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 charging performance test chart recorded on 'Megger' graph paper.
| Identifier | ExFiles\Box 54\2\ Scan135 | |
| Date | 3rd July 1926 | |
| 3-7-26 175 P&R RR11-2 75 a.h. 97 lbs. Charged on a fixed PD of 17 volts with .25w resistance in series. Average amperes = 6.34 Hours = 10.3 Ampere hours = 65.3 673 1.80w REG'D TRADE MARK 'MEGGER' | ||