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).
Solutions for overcharging batteries and side lamp burnouts on the New Phantom.
| Identifier | ExFiles\Box 26\2\ Scan264 | |
| Date | 23th January 1926 | |
| Contd. -2- EFC2/T23.1.26. As you know, we are now having complaints of side lamps burning out on the New PhantomCodename for PHANTOM I, and this is undoubtedly due to people overcharging their batteries. There are also complaints of high output, which is practically the same thing. For immediate correction on existing chassis there are four possibilities, and as far as I can see at the moment, only these four :- (1) Tell customer not to charge so much, i.e. to run sometimes on the B position of the switch. (2) Suggest owner obtains side lamps of higher rated voltage, if possible. (3) Suggest insertion of resistance in side lamp circuit to restrict side lamp current to a suitable value. (4) Arrange for one of our men to cut the twin control brushes away on their trailing edges so as to run with 2/3 of the present circumferential width, and thus move the centre line of the working surface of the brush in such a direction as to correspond to reduced output. This would now be justifiable in view of the results of our experiments of narrower brushes. It is probable that in most cases, at any rate of the chassis of which we have received complaints, that these chassis are fitted with P & R batteries. We know and have shown and proved it to the P & R Company that their batteries put up a bigger charging E.M.F. than the Exide batteries, and are therefore worse for putting up the P.D. of the system when the battery is fully charged. They have already made an improvement which we have experienced on the latest battery received from them, and it should take effect on the batteries which we are now receiving on production. This has reduced the charging E.M.F. nearly down to that of the Exide, and they are still working to reduce it further. It is a matter of the pasting and to some extent of the separators. Contd. | ||