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 requirements for the vehicle's battery charging system and electrical load calculations.
| Identifier | ExFiles\Box 31\1\ Scan046 | |
| Date | 31th December 1919 | |
| HHS A (100) T: (S.F. 846. 6-8-19) a.{Mr Adams} 2460 Gr{George Ratcliffe} 1K 12/31/19. 2. Contd. (c) The regulation should be capable when the battery is fully charged, of controlling the current input to the battery within a predetermined figure; to eliminate excessive gasing and oxidation at the plates and the attending disintegration of the plates. It is considered of the utmost importance that a low constant charging rate at all speeds be obtained and maintained by the system when the battery is fully charged. I have not as yet been able to make exhaustive tests of the actual current amounts taken from the battery under general service conditions. It is believed that the work which the battery will have to perform will not be heavy. It is estimated a current of around 100 amps. is necessary to turn over the engine for starting, and in view of the perfection of balance, and carburation of the engine, and the usual ideal conditions under which the car is housed and handled, the current taken from the battery should never be excessive. The current used for coil ignition average between one and two amps. which is infinitesimal in view of the fact that it is usual practice to throw the magneto in line after starting. The lighting load should never be more than 10 amps. and in general practice around 8 amps. This and it is desired that the generator should take care of this load, and with the units functioning correctly, the lighting load should generally be taken care of by the generator. The Klaxon horn takes a mean current of around 6 amps for each time it is used. The car is often called upon in this country to do many hours of continued running when charging is continuous, and little or no current will be taken from the battery. In consultation with yourself before you left for England, it was considered the most desirable system would be one capable of controlling both the voltage and current output; comprising a plain shunt wound generator of ample Contd. | ||