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).
Comparison of Edison and Exide accumulators, detailing weight per amp hour and voltage variation during discharge.
| Identifier | ExFiles\Box 1\7\ B001_X15 20 46 50 59-page228 | |
| Date | 17th July 1913 | |
| Mr Wormald Mr Royce HR.6/c2 July 17/13 X50 Reply to Memo. June 25/13 7.H.R.6/@25613 Re Accumulators:- Weight. per Amp Hour (Actual) Edisons 12 Volts. Discharging rate 8 amps = .81 lbs " " " " " "4.8 cell" sanction by "1" " = .55 lbs Exides 4 " " " 28.5 " " = .38 lbs " " " " " 3 " " = .33 lbs The weight of a 12 Volt Exides will be 3 times the weight of the 4 Volts. We have no Exides for heavy discharge on but Mr Nadur states that there is a set on order for lighting work. Variation of Voltage on Discharge Edisons 12 Volts. 12.2 Volts at the commencement of discharge after fully charged. 10.8. volts at which the cell must be recharged. 1.4 volts variation on 12.2V = 11.4% Exides 4 Volts. 4.2 Volts. at the commencement of discharge after fully charging. 3.6 volts. at which the cells must be recharged. .6 volts. variation on 4.2V = 14.3% Continued | ||