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).
Instructions for battery testing, charge level assessment using a hydrometer, and charging procedures.
| Identifier | ExFiles\Box 26\2\ Scan094 | |
| Date | 6th August 1919 | |
| R.R. 255 a (100 T) (S.F. 846 6.8.19) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2460 -7- Contd. If this is noticeable it indicates an abnormal drop in voltage which may also be observed by using a pocket voltmeter before and after switching on the lights. Each cell should then be tested with the voltmeter separately (the lights still being on) to ascertain whether any of them is faulty. No cell should indicate less than 1.8 volts. As a bolted up connection is used between the cells it will always be possible to have a new cell to replace a cell of the battery which is faulty for any reason, although it is not considered likely that any one cell should become faulty more quickly than the rest if proper care be taken of the battery. If the battery is in ordinarily good working order and care is taken to keep the densities, when in a fully charged condition, round about 1.225, as already described, the state of the charge of the battery will be very well indicated by density readings taken with the syringe type hydrometer. If the readings are 1.175, the battery may be considered in a half discharged condition. If the readings are down to 1.125 the battery must be considered in a discharged condition. Charging in Garage. A direct current supply is necessary for charging purposes. An alternating current may be used but only with the interposition of special apparatus to render the flow unidirectional. If a direct current supply is | ||