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).
Technical discussion on vehicle electrical system voltage, battery charging rates, and lamp longevity on the Phantom generator.
| Identifier | ExFiles\Box 71\2\ scan0015 | |
| Date | 31th December 1925 | |
| Contd. -2- EFC4/T31.12.25. may, and in fact often does, reach 18.5 volts. Insofar as the battery itself can be expected to reach 17 volts, it is clear that it is not altogether a question of the generator output, and that the lamps should be capable of standing 17 volts at least. If they will not do this, and the same lamps must be used, the only possible course is to lower the current through each lamp circuit by the inclusion of a small resistance units. as it is extremely doubtful if the amount of reduction in the output which can be allowed from other considerations will be sufficient to make the difference. It would be impossible for instance to do as suggested - to reduce the maximum charging rate of the Phantom generator to correspond to a maximum voltage not exceeding say 15.5. If we did this we should never be able either to keep the battery up, or to fully charge it, even if it were not over discharged. Presumably it is the side lamps which suffer when head lamps are not on, because this is the condition when the voltage would be highest. The load of the head lamps would cause a reduction in the voltage, and there would not be much trouble with these burning out. This is our experience over here. Contd. | ||