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).
Technical letter discussing battery cell removal, moulded materials, and impurities in Dagenite.
| Identifier | ExFiles\Box 38\5\ Scan305 | |
| Date | 27th February 1923 guessed | |
| -2- Contd. With regard to your point about removing a faulty cell, now that six cell batteries have the connections burnt together this is no more serious with a moulded 6 compartment box than with 6 separate cells. In either case the battery cannot be used until the fault is put right. Actually, however, the removal of a section and refitting would be easier in the case of the 6 compartment box. It is true that one cannot replace a cells, but we cannot see how circumstances could arise to make this necessary. If anything happened to damage a cell in such a substantial structure as the six compartment moulding, similar treatment to a battery made of 6 ebonite cells in a wood box would surely wreck the whole battery utterly. With regard to your question about metallic impurities in moulded material, your informant may be under the misapprehension that metallic impurities and mineral matters are one and the same thing. Dagenite is free from metallic impurities but contains a proportion of mineral matter which is incorporated to impart mechanical strength and other desirable features. Exhaustive tests have shown that the mineral matter used in Dagenite mouldings have no deleterious action which is further demonstrated by experience of batteries in use for long periods. You are right, therefore, when you say we shall answer by saying that our tests have shown that the presence of such ingredients is of negligible effect so far as Dagenite is concerned. With regard to making tests, we have no objection at all to your chemist examining the material and we have instructed our Works to send you a box. We shall be interested to hear further from you regarding your chemist's examination and to answer any questions he may care to make ask. Moulded boxes for train lighting are used all over the world and have been for many years and we have never heard of trouble arising from metallic impurities. With regard to Dagenite in particular, we have used this mixture for twelve years and there are in service Dagenite mouldings subjected to sulphuric acid to the number of over half a million. We have never heard of any trouble arising from mineral impurities in Dagenite. Dagenite is in use on most of the leading railway companies in the world and has been for 12 years. Contd. | ||