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 from a Megger instrument showing the results of a battery discharge test.
| Identifier | ExFiles\Box 54\1\ Scan198 | |
| Date | 23th March 1926 | |
| 9 7 SV 8 9 10 11 12 23-3-26 177 Sandwich SV 103 lbs 75 a.h. REGD TRADE MARK 'MEGGER' Average amperes = 6.25 Hours = 6.55 Ampere hours = 41.1 .400 1.80w | ||