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).
Test report on a faulty P & R battery from chassis 36-HC.
| Identifier | ExFiles\Box 70\3\ scan0049 | |
| Date | 15th April 1926 | |
| EFC. JC.20. 15.4.26. P & R BATTERY FROM CHASSIS 36-HC This battery was returned to us from chassis 36-HC in a dry condition, it had been reported faulty. The battery was first of all filled with distilled water and charged at 4 amperes for 40 hours, all the cells were gassing normally and the density had risen to 1180 showing that some sulphate had come out of the plates. The electrolyte was then emptied away and the battery was filled up with acid of correct density and charged again. All the cell densities and voltages were quite normal. remained The battery was then given a low rate discharge through an invariable external resistance of 1.80 Ohms and gave 64.0 ampere hours. Cadmium readings showed both the positives and negatives to be O.K. on every cell. The battery was again charged up and given a high rate discharge through an invariable external resistance of .100 ohm. Initial amperes = 105 Time to 104 " = 3.1 mins. " " 100 " = 8.0 " " " 90 " = 14.6 " " " 80 " = 16.2 " Cadmium readings in this case showed negative weakness. Both of the above results are good and show that there is now nothing wrong with the battery. If the battery was shorting at the time it was reported, the emptying out of the acid may have dislodged the material which was causing it to short. A sample of acid was sent with the battery and the density of this was much too high being 1300 besides what had gone into the plates in sulphate. The maximum density should be 1250. An analysis of this acid showed no impurities only in very small quantities which were negligible. EFC/G.Johnson. | ||