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 risks and benefits of using a two-battery system in parallel.
| Identifier | ExFiles\Box 70\3\ scan0085 | |
| Date | 22th January 1929 | |
| X8783 BY/Cgh.{W Clough} from EFC. EFC3/T22.1.29. Our remarks on Mr. McCarthy's final paragraph are as follows :- We do not approve the suggestion of inserting a switch of any kind in the main battery lead, because this increases the risk of a broken battery circuit, which is a dangerous condition of the electrical system generally. The only feasible way of using two batteries on a system, the voltage of which is not automatically controlled irrespective of the battery, is to put them permanently in parallel. There is, in certain circumstances, an advantage in the use of two batteries when the size of the generator is not increased. Obviously the storage capacity is greater and the risk of deterioration through overcharging considerably less. The advantage occurs when a considerable amount of daylight running is followed by a considerable amount of night running. It is obvious, however, that in circumstances in which the generator can only just keep pace with the demand, the extra battery is of no advantage whatever, unless the output of the dynamo be also increased. We return herewith your papers. EFC. | ||