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).
Battery charging rates and internal resistance issues on the 'New Phantom' model.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan167 | |
| Date | 23th November 1925 | |
| To R.{Sir Henry Royce} from EFC. c. CJ. c. BY.{R.W. Bailey - Chief Engineer} ORIGINAL EFC2/T23.11.25. x8730 x8660 x I think you probably know that Mr. Minchin of Messrs. Peto & Radford is displeased with our switch positions on the "New PhantomCodename for PHANTOM I", and is uneasy about batteries because he feels sure that whatever we tell owners about the sufficiency of the firing characteristics of the battery ignition, they will nearly all run on magneto, battery and charge practically the whole of the time. He is very anxious that we should reduce the charging rate of the dynamo. It is, however, a fact that variations which occur from chassis to chassis are largely due to the variations in the internal charging resistance of the battery, and this happens to be a good deal higher in the case of the P & R than the Exide batteries. We on our part are therefore asking Messrs. P & R what they can do to reduce this quantity. As an instance, on one observation on a chassis with a fully charged and charging sandwich battery, we found P.D's of 2.5 volts on each Exide cell and P.D's of 3.0 volts on each P&R cell. This variation is purely a charging phenomenon - the internal resistances of the two batteries on high rate discharge are approximately equal. We are suitably investigating the whole matter | ||