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).
Dynamo output, increased electrical load from features, and battery charging methods.
| Identifier | ExFiles\Box 32\5\ Scan028 | |
| Date | 23th December 1929 | |
| X1589 EFC. c. R.{Sir Henry Royce} c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} c. PN.{Mr Northey} EPL3/H23.12.29. X.294 X.8780 X1589. RE - DYNAMO OUTPUT. With reference to the recent correspondence on the above, the following are points for your consideration :- (1) The current taken by the necessary features, such as head, side and tail lamps, ignition etc. on present new cars very much exceeds the dynamo maximum output. This used not to be the case. We have not reduced our dynamo output but increased the current required, much bigger C.P. bulbs now being used. We used to specify size of bulbs required, i.e. 50 watt for head lamps. These now take 6 and 7 amperes each. Should we not recommend limits on the size of bulbs to be used (as we do the side lamps, in the Instruction Book)? (2) My experience has been that the most successful scheme is a half charge switch, used by Lucas. A dynamo of the "mjaor output" - full charge for winter and night use, and half charge summer time or touring. Months of careful observation show that the batteries are kept well within the limits of over charging or under charging. (3) Charging the battery from an external source I find is not now difficult to get the customers to do. Most of them are wireless enthusiasts and have battery chargers which are now easily obtainable. One of the most successful scheme I have used myself is to have the valve (rectifying) capable of being fixed inside the bonnet. Besides charging the batteries, it also prevents freezing up at a time when both features require attention. The scheme should appeal to efficient motorists, in fact encourage external battery charging. A battery charger of this type should be readily made up if the suggestion were put to the manufacturers. EP.{G. Eric Platford - Chief Quality Engineer} | ||