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).
The testing and evaluation of a Multiple Storage Type C.A.618 battery, detailing its condition, design flaws, and performance results.
| Identifier | WestWitteringFiles\E\August1920\ Scan10 | |
| Date | 20th August 1920 | |
| To Bn.{W.O. Bentley / Mr Barrington} from EFC. c. to R.{Sir Henry Royce} c. to CS. c. to EWT. for U.S.A. ORIGINAL. X.3711 - MULTIPLE STORAGE TYPE C.A.618 BATTERY. This battery was received on 31st. Dec. last as two separate 6 volt sets, each rated at 180 ampere-hours. The cell to cell connections are good but no terminals were supplied with the battery; there were only conical lugs projecting at either end. We accordingly had to make some suitable terminals. The battery is provided with good filling holes, but the vents are poor inasmuch as they allow much acid to get on to the top of the battery during charge. There is difficulty in taking density readings on account of the design of the battery. Three cells of each set are completely sealed together over their tops. We considered that the battery was rated too high and set the rating at 120 ampere-hours, a rating which was suitably confirmed by the actual experimental results. The two batteries together weigh 167 1/4 lbs. The battery was first of all charged nearly continuously at a relatively slow rate with a total ampere-hourage of 468. It was then discharged at 12.0 amperes to 10.5 volts in two periods, separated by a night interval, and gave 117 ampere hours. It was then suitably recharged with 295 ampere-hours, the acid changed and levels Contd. | ||