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 operation, battery charging methods, and their effects on component wear and battery life.
| Identifier | ExFiles\Box 59\1\ Scan207 | |
| Date | 9th December 1927 guessed | |
| Contd. -6- (132) If, as is practically the case, the dynamo runs alternately at full output and then at no output, the total wear on the brushes is less in this way than if that machine were running all the time at its time average of output. The flux distortion at half rate of charge might be such as to make the wear on the brushes nearly as much as if it were running on full charge. (133) In avoiding vibrator regulator action, the duty of the points is so much reduced. (134) Speaking of the low frequency vibration, although this does no serious harm it is just as well to overcome the slight flickering in normal running which would result from it by avoiding such vibration, and to save the life of the contact points of both the auto switch and the cutout. GENERAL. We are of the opinion that the fact of being able to go over from full charge to no charge and back again to full charge is probably better than the half way scheme of going from full charge to half charge and back again, not only from the point of view of saving the wear on the dynamo brushes as explained, but also from the point of view of the battery generally, viz. that there can be little serious gassing, and when the battery is charged, no continued gassing at half rate. In the circumstances in which a battery is used on a car with frequently recurrent charging, it is doubtful whether it is ever necessary to give the battery a special overcharge. Though it is impossible to arrive at a quite definite conclusion on this point, our feeling is that in these the circumstances of the case are that the battery can, be in them, be looked upon very largely as a tank which, with the proposed type of Contd. | ||