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).
'Megger' chart recording results from a test on two multiple storage units in series.
| Identifier | ExFiles\Box 41\2\ Scan156 | |
| Date | 13th February 1922 | |
| 26 2 MULTIPLE STORAGE IN SERIES Amps per div = .293 Average amperes = 9.9 Ampere hours = 127.9 | ||