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).
Battery charging and discharging performance tests.
| Identifier | WestWitteringFiles\E\August1920\ Scan11 | |
| Date | 20th August 1920 | |
| Contd. -2- EFC1/T20.8.20. and densities adjusted, and again discharged at the same rate to the same terminal voltage when it gave 110 ampere-hours. Thirdly, it was suitably recharged with about 200 ampere-hours and then discharged at 20 amperes to 10.0 terminal volts, during which discharge 96.6 ampere-hours were realised. The ampere-hours per pound in the two latter cases are .587 and .525, which are not good compared with our standard Chloride battery, which generally gives about .8 ampere-hour per pound (for the same number of cells). After again charging the battery, it was subjected to a continuous high rate discharge test through a resistance of .0763 ohm. The battery started off by giving 137 amperes, the current gradually falling to 120 amperes in a period of 24 3/4 mins. and to 100 amperes in a period of 27 1/2 mins. It is not, however, easy to draw a comparison between this high rate discharge performance and that of the standard battery, as the rate of discharge per square inch of plate is considerably less, which increases the prolongation of the discharge. It was not considered necessary to give this battery an intermittent high rate discharge so it was finally recharged and discharged on a recording voltmeter. At the start the current was about 10.4 amperes and the discharge was allowed to continue until the slope of the curve made a sudden change in the downward direction, this point corresponding to about 10.7 volts on the terminals at 9.2 amperes Contd. | ||