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).
Instructions on charging procedures, acid changes, and acid density for celluloid and ebonite accumulators.
| Identifier | Morton\M2.3\ img013 | |
| Date | 10th March 1920 | |
| Contd. -2- Ck{Mr Clark}1/T10.3.20. Further, the first charge need not necessarily be continuous but may be given in cycles of not less than a given number of hours charge (usually 12); alternating with not more than the same number of hours rest. In any case the first portion of the charge should be continuous for 12 hours, after which the charge may be completed intermittently provided the intervals of rest do not exceed the periods of charge. Again, the first charge need not be at as high a rate as specified, but the charging rate may be lowered and the time extended accordingly. The first charge must always be a very full charge. It is absolutely necessary that all plates shall gas freely. (2) CHANGE OF ACID. In celluloid accumulators, the acid should be changed at the end of the first charge to get rid of impurities derived from the celluloid, and the accumulator should subsequently be put on charge again for a short period. In ebonite accumulators it is considered unnecessary to change the acid as no impurities are derived from the ebonite, and the plates are already devoid of impurities owing to the careful manner in which the materials are selected and tested. New acid should be put in celluloid accumulators only, every twelve months. (3) DENSITY OF ACID. Ebonite accumulators are best worked with a higher density than celluloid, namely, 1280 for ebonite and 1250 for celluloid, when fully charged. A density higher than 1300 appears to be bad on account of chemically attacking. Contd. N.R. 235 A (100) T (S.) F 846 6.8.19. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2460 | ||