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).
Letter discussing a provisional patent for a battery gassing indicator and its operation.
| Identifier | ExFiles\Box 60\3\ Scan012 | |
| Date | 8th April 1927 | |
| X4040 ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. Oy3-E-4827 April 8th, 1927. Mr. E. {Mr Elliott - Chief Engineer} W. Hives, Rolls-Royce, Ltd., Derby, England. (Copy to Mr.E.F.Clark) Dear Sir: Battery Re Gassing Indicator We have received provisional patent specification and note some comments on the gassing indicator for batteries. We are given to understand, by battery makers, that a modern battery takes no harm from ordinary automobile charging rates and consequent gassing. In fact a rough allowance in third-brush systems is an output from a hot generator at average road speeds of one ampere per plate, i.e. 21 amps for our 6 volt, 21 plate batteries. However the battery is harmed by a low water level, and there is a device on the market which indicates when the battery level falls below the critical amount. As far as I recall it this consists of a special filling plug for one cell having two electrodes non-corrosive and of similar metals projecting downwards to touch the liquid at the critical level. Current passes from one to the other through the electrolyte and lights a tell-tale lamp on the dash. When the liquid gets too low it fails to touch the two electrodes, breaks the circuit, and the lamp goes out. If you are at all interested I can get to know more about it, but it seems a simple thing to make and try. Yours very truly, Maurice Olley MO/E | ||