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).
Letter from Peto & Radford discussing battery performance, cell gravity readings, and charging current observations.
| Identifier | ExFiles\Box 59\1\ Scan135 | |
| Date | 22th April 1927 | |
| X4008 1726 Works, Dagenham Dock, Essex TELEPHONE VICTORIA 3667. 5 LINES PRIVATE BRANCH EXCHANGE. [LOGO: MOTOR TRADE ASSOCIATION] [LOGO: INCORPORATED IN THE YEAR 1905] [LOGO: THE SOCIETY OF MOTOR MANUFACTURERS & TRADERS LTD.] TELEGRAMS CONCENTRATION, SOWEST, LONDON. Manufacturers of P & R Accumulators. Established 1889 PETO & RADFORD Proprietors - Pritchett & Gold and E.P.S. Company Ltd. 50 GROSVENOR GARDENS, LONDON S.W.I DIRECTORS: SIR ARCHIBALD C. GOLD F.C. GRAHAM MENZIES O.R.N. MINCHIN WILLIAM PETO C.R.D. PRITCHETT T.W. PRITCHETT. YOUR REF._________ OUR REF.____M/5. 22nd April 1927. E.{Mr Elliott - Chief Engineer} Fowler Clark Esq., Messrs. Rolls Royce Ltd., DERBY. Dear Fowler Clark, X8660 X4008 Thanks for your letter of the 18th inst. with copy of your further report on your automatic device. In that report I see you refer to the letter I wrote you some time ago and I have just recently had the gravities of my cells read, which confirms my impression that the battery has been kept up fully charged. They are as follows:- Positive end cell 1235, 1235, 1245, 1250, 1245. Negative end cell 1255. The charging current has been less, I think, than you intended it to be. I do not think I have ever seen it above 7 amps and its normal running is certainly under 5, that is with the battery ignition working. This shows, I think, in a very striking manner how small a current will keep a battery up, which is what we have been contending for a long time past. It has also been noticeable that the battery has not required anything like so frequent topping up with water since this reduced output dynamo has been on the chassis. With regard to the report in general, I think that what you have done is extremely satisfactory as far as you have gone, and I should think it is a thing that does not need a very prolonged test, that it would either work properly straight off or not at all. | ||