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 bench testing and performance analysis of a P & R battery from a 40/50 School Car.
Identifier | ExFiles\Box 38\5\ Scan315 | |
Date | 11th June 1923 | |
X.3398. To Hr. from EFC. EFC2/T11.6.23. X.3398 - P & R BATTERY ON 40/50 SCHOOL CAR. You will recall that recently we changed the battery on this car for one of similar make and type, namely, P&R BDT.11. We have, however, found nothing whatever wrong with the battery taken off, except that it did not appear to be fully charged when removed, as in this condition, put to discharge through an external resistance of .1 ohm, the current given remained over 100 amps., (voltage about 10) for only 4 1/4 minutes. After recharging and taking the low rate discharge through a constant resistance of 1.17 ohms, the battery, discharging at an average ampere rate of 9 1/4 amps., gave 56 3/4 ampere-hours, this figure being approximately the same as when previously discharged on low rate about six months ago. After another charge, another high rate discharge was taken. This time the battery complied readily with our specification (which requires the amperes to remain in excess of 100 for 8 mins); actually discharging through this resistance of .11 ohm, the amperes remained above 100 (volts about 10) for over 12 mins. Is it possible that there was some other feature about the electrical equipment which caused your man to form an apparently erroneous opinion about the condition of the battery ? The battery given you in exchange was only recently initially charged, and its initial performance on the bench test was not so good as the result obtained from the old one. EFC. | ||