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 on testing the condition of a battery's charge using a 'Battery Indicator' or a syringe hydrometer.
| Identifier | ExFiles\Box 26\2\ Scan161 | |
| Date | 1st August 1919 guessed | |
| -11- TESTING FOR CONDITION OF CHARGE. No voltmeter is provided on the electrical system as this is not considered necessary. A small "Battery Indicator" is obtainable from Messrs. Lucas complete with short length of flex and plug for insertion in Lucas switchbox inspection lamp socket. This is a useful little instrument and indicates directly the state of charge of the battery, but these indications must only be taken when head lamps are lit from the battery, with the charging switch off. The reading of such an instrument or voltmeter when the battery is on open circuit is quite a fallacious indication of the condition 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 1280, as already described, the state of the battery will be very well indicated by density readings taken with the syringehydrometer. If the readings are 1200 to 1225 the battery may be considered to be half discharged. If the readings are down to 1150, the battery must be considered in a completely discharged condition. | ||