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 car battery specifications, potential overcharging, and modifications to increase capacity.
| Identifier | ExFiles\Box 51\1\ Scan179 | |
| Date | 19th July 1923 guessed | |
| PETO & RADFORD. CONTINUATION 1. Messrs. Rolls Royce Ltd., We think the battery we have supplied is big enough for the car if you were to reduce the charging current, but it appears to be rather overcharged at the present time and you may not get the life out of it that you should do. We quite appreciate your difficulty as to increasing its size and realise that the only dimensions that you could possibly vary to increase the size is the height. By re-designing the box and getting a thinner lid {A. J. Lidsey} and a thinner base and allowing the lid {A. J. Lidsey} to come up a little bit higher and the base to be a little lower, you might possibly get 1 1/4" extra height, but this however, is a matter for you to say whether it is possible or not. No maker that we know of makes a plate suitable for such a dimension, but there is no reason why it should not be made quite successfully and we would be prepared to make it for you. This would give you an increase in capacity of 25% (with about 15% to 20% increase in weight) thus bringing the capacity of our T.B.D.7 from about 52 ampere hours to nearly 65 ampere hours. The charging current shown on your curve would then probably be just all right for such a battery, but we cannot help feeling that in practice more current goes into the battery than is shown in your curve and we wish you could assure us that this is not so. Yours faithfully, PETO & RADFORD. G.R.N. Minchin. | ||