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).
Dynamo charging systems, battery overcharging, and advocating for a three-rate charge scheme.
| Identifier | ExFiles\Box 47\3\ Scan116 | |
| Date | 7th March 1931 | |
| HS{Lord Ernest Hives - Chair}/Pgt2/ADS.7.3.31 contd. -2- If, after a complete examination, the dynamo still appears to be at fault, we should very much like to have the machine here for investigation on the bench. There is no necessity for warning customers to switch off the charging current when the battery is fully charged, in order to prevent the dynamo from overheating, or the field fuse being blown. Generally, the dynamo and its charging circuit are so arranged that when functioning properly, the dynamo is capable of running indefinitely at maximum output on a fully charged battery without any damage being done beyond what is done to the battery itself through overcharging at a high rate. From the point of view of reducing disintegration of the battery and so prolonging its life, and the annoyance to customers arising from the frequent topping up of the battery, the customer is advised in the Instruction Book to use the charging switch with discretion, and is given some information and suggestions for guidance. We agree that it is difficult in so far as no definite instruction on this point can be given to the customer, and it is for this reason that we favour a three-rate charge scheme similar to that adopted by Lucas. This, we think, is the simplest compromise and more likely to give satisfaction to all the various types of driver under all the possible conditions of driving. A driver could then be instructed to run normally on the lower charging rate (say 7 to 8 amperes) and only use the higher rate (say 12 to 13 amperes) when he found that his battery was going down. The full output would, as at present, come on with the side and tail lights. Hs{Lord Ernest Hives - Chair}/C. A.{Mr Adams} Pignatt. | ||