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).
Examination and review of a 'Davenset Battery Charger' submitted by the makers, Partridge and Wilson and Co. Ltd.
| Identifier | ExFiles\Box 164\3\ img100 | |
| Date | 3rd January 1938 | |
| To Hn.{F. C. Honeyman - Retail orders} c. to Hd.{Mr Hayward/Mr Huddy} c. to W/P - Sr. c. to W/K 60211 Rm{William Robotham - Chief Engineer}/RC.{R. Childs}14/JH.3.1.38. Davenset Battery Charger. Apparatus of the above type was submitted by the makers, Messrs. Partridge and Wilson and Co. Ltd., for our examination, as a preliminary to their seeking permission to indicate in their advertisements, that the apparatus was approved by Rolls-Royce. The apparatus consisted of a transformer and rectifier, the rectifier being of the valve type, with what appeared to be a double anode and cathode, giving a full wave rectification characteristic. In addition there were two lamp type resistance units. Generally the construction was good although we prefer the metal type rectifier. The whole is designed to charge a 12 volt battery. A well descharged battery was connected to it, when the charging current was 4.5 amperes. As charging progressed the current fell until with the battery charged to just gassing gently the current was more or less constant at 2.9 amperes, the terminal volts 13.25 and the density of the acid 1.265. The charging current observed would have probably been higher if the mains supply had been up to the full 200 volts, but even so, the charger appears to have been designed on the safe side, and is quite suitable for charging our batteries. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} | ||