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).
Specifications for car battery construction, components, and maintenance considerations.
| Identifier | WestWitteringFiles\M\2October1924-December1924\ Scan57 | |
| Date | 8th March 1924 | |
| -5- (14) SEPARATORS. The material and thickness of the separators should be such as absolutely to prevent any possibility of short circuits from plate to plate during the life of the battery. Ribbed wood separators must not be used alone, but with such it will be necessary to insert, in addition, perforated ebonite sheets between the wood separators and the positive plate surfaces. The percentage area of cross section of the perforations must, however, not be so small as to put up the internal resistance of a cell so much as to prevent the battery complying with items (2) and (3). (15) SPACE AT BOTTOM AND ABOVE PLATES. Ample space must be provided at the bottom of the cells underneath the plates to allow for the accumulation of all the matter that is likely to be lost by the plates during the life of the battery, without such matter piling up so as to reach the plates and cause short circuit. A considerable space must also be allowed above the top of the plates, to prevent the necessity of too frequent topping up, and to allow of the vents being sufficiently clear of the electrolyte so as to minimise the efflux of acid from the vents during charge. (16) OVER-FLOW OF ELECTROLYTE. The location of the filler holes and the design of the vents shall be such as to minimise the possibility of the electrolyte coming or spraying out on to the top of the battery during charging, or due to the swerving motion of the car. At the same time the filler holes should be large enough and so placed as to make the process of filling easily performed without spilling acid on the top of the battery. Also care should be taken that it is possible to insert the rubber tube of a syringe type hydrometer with sufficient depth of acid available above the plates to draw upon for a density reading. The filler holes should also be such that it is easy to inspect the level of the acid above the plates through them. (17) VIBRATION. The battery shall be so constructed as to withstand, without deterioration, what little vibration it would be subjected to on an R.R. car. The chafing of the plates against the separators due to inertia effects on bad roads should be considered. (18) NEGLECT. Consideration should be given to the fact that a car lighting and starting battery is almost certain to be | ||