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).
Investigation into an Exide battery's acid overflow during gassing and a proposed modification.
| Identifier | ExFiles\Box 47\4\ Scan030 | |
| Date | 2nd July 1924 | |
| EFC. JB.49. RE INVESTIGATION OF 56.S.3. EXIDE BATTERY. When received this battery was put in our E.M.S. battery circuit and when fully charged the S.G. was found to be only 1210 and so had to be adjusted before any investigation could be made. After this had been done the acid just reached the top of the separators and it was found that it only required 25 cc's of water to reach the bottom of the vent hole. With the stoppers removed, the acid at this level when gassing came up and overflowed, but when the ring in the vent hole was given a quarter turn the acid went down again because the gases could get free through two holes provided in the sides of the vent hole. When the stoppers are put in and given a quarter turn it appears O.K. but if turned back a little the acid comes out over the top. Probably the stoppers were not turned fully by the client when it was on his car, in which case if filled to the bottom of the vent hole it would overflow when gassing, because there is no other way for the gasses to get free. Another point which is rather misleading and worth pointing out, is that the separators project about 1/4" above the plates and this makes people think that if these show above the acid, it wants topping up when it does not require it. I think the idea is to keep the separators down in position, but so as not to be so misleading and still keep to this idea, could not part of the separators be cut away (level with the top of the plates) in the centre (as per sketch):- Plate connecting bar. Separator. Acid level Plate. it would not then require so much topping up and also a better hydrometer reading could be obtained. EFC/GJ. | ||