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).
Arguing against the use of an inferior battery for economy reasons, detailing the technical disadvantages.
| Identifier | ExFiles\Box 58\3\ Scan177 | |
| Date | 1st February 1931 | |
| To WOT. from EFC. {E. Fowler Clarke - Electrical Engineer} c. Dr. c. Hs. {Lord Ernest Hives - Chair} X6107. EFC {E. Fowler Clarke - Electrical Engineer} 5/AD6.2.31. X.6107. JAPAN 3. BATTERY. With reference to Da {Bernard Day - Chassis Design} 3/M23.1.31, we are not in favour of attempting to appreciate an economy through the use of a battery of construction inferior to that of our present 20/25 6TBD7-K. {Mr Kilner} As pointed out in our EFC {E. Fowler Clarke - Electrical Engineer} 4/AD6.2.31, no economy results from the use of the 6 in line arrangement of cells. It is possible that a slightly greater temporary advantage might be realised from the use of a battery of greater rated capacity. It must be remembered, however, that the comparison of rated capacity is based on the 10 hour rate of discharge (even though also given on the 20 hour rate) and it does not follow that a battery of greater capacity on the 10 hour rate will have a greater capacity on a slow rate of discharge as, for instance, on side lamp standing lighting. There are several other reasons why we are of the opinion that, even though the first cost is less, an economy would not in the long run, be effected. These are :- The greater capacity battery in smaller space means more overcrowding of the plates. This results in less acid room and a greater rate of deterioration on starter work owing to the rapid local fall of electrolyte density. It is true that in the case of a starter demanding a very heavy current the smaller internal resistance of such a battery is an advantage. This does not carry much weight with our starter which is not arranged so as to demand a heavy current from the battery. The smaller acid space also necessitates more frequent attention for topping up. This we should regard as a serious item especially as our batteries | ||