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).
The condition and testing of an Exide battery from a 20 HP car, chassis GYK.40.
| Identifier | ExFiles\Box 57\2\ Scan007 | |
| Date | 6th January 1927 | |
| EFC. {E. Fowler Clarke - Electrical Engineer} 6.1.27. RE 20 HP. EXIDE BATTERY EX CHASSIS GYK.40. Battery when received was discharged, No.1 cell being lowest and shewing positive weakness on the cadmium. The acid density was also lower. The battery was then fully charged. Density of No.1 cell 1255, others 1275. On discharge it gave 46.7 ampere-hours, No.1 cell discharging first and shewing positive weakness on the cadmium. Battery charged again and high rate discharged. Initial amperes = 105 Time to 100 amps.= 3.0 mins. " " 90 " = 10.0 " " " 80 " = 11.0 " All cells shewed positive weakness on the cadmium. By this it seems that the cells have been overcharged, deteriorating the positive plates and causing positive weakness, but something internally must be wrong with cell No.1 for this to be worse than the others, or it may possibly be due to the density being low in this particular cell. EFC {E. Fowler Clarke - Electrical Engineer} /G.J. | ||