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).
Page discussing acid density, frothing, and the proportion of acid to plates in celluloid and ebonite batteries.
| Identifier | Morton\M2.3\ img014 | |
| Date | 10th March 1920 | |
| Contd. -3- Ckl/T10.3.20. the plates themselves. Acid of higher density than 1250 cannot be used in celluloid batteries for good results, because such acid attacks the celluloid and produces acetic acid which latter acid, when the sulphuric acid becomes of low density due to discharge, is enabled to attack the positive plate produc-ing substances which cause frothing during charge. This frothing there is no suitable means of preventing. (4) PROPORTION OF ACID TO PLATES. The proportion of acid in cells in relation to plate volume should be above a certain figure, otherwise the capacity of the cell is too much limited by the dwnsity of the acid becoming low, whereasmit is desirable for the capacity to be limited by the plates only. Therefore, except for practical limitations, the larger the quantity of acid, the better. Another reason being that the density with the larger quantity of acid cannot become so low for the same amount of discharge and therefore cannot so readily allow sul-phating to take place due to discharge. Further, since it is undesirable to have the acid density too low in celluloid accumulators, owing to the fact that any acetic acid present is thereby enabled more readily to attack the positive plate, it is desirable to permit a rather greater ratio of acid volume to plate volume in celluloid batteries than in ebonite. Contd. H H B 332 W (100 L) (T.B.) RVC 8-8-19 C 2460 | ||