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).
The inspection of an 8-cell battery, detailing issues from excessive charging and advising on future use.
| Identifier | ExFiles\Box 61\1\ scan0029 | |
| Date | 31th March 1926 | |
| X2065 PRITCHETT & GOLD AND E.P.S. COMPANY, LIMITED. 50, GROSVENOR GARDENS, LONDON, S.W.1. WORKS: DAGENHAM DOCK, ROMFORD, ESSEX. Date of Report: 31st March, 1926. REPORT ON INSPECTION OF BATTERY installed at Messrs. Rolls-Royce, Nightingale Road, Derby consisting of 8 cells F.A. 11 type Date supplied Feb. 1924. Reference No 9569 Owner's Name Messrs. Rolls-Royce Ltd. Date of Inspection 29th inst. Messrs. Rolls-Royce Ltd., Nightingale Road, Osmaston Road, Derby. Dear Sirs, We beg to report following inspection visit on above date to your request that this battery is suffering at present to a rather marked extent as a result of excessive charging. The negative plates are in good order in all cells but are coated with sponge growth formation, while the positives possess an extremely well charged appearance; are more worn and buckled for the service obtained than should be expected in the circumstances. We advise that the buckled positives be straightened, all cells requiring this attention and if the work is carried out in a careful manner we consider that the plates will straighten satisfactorily. We advise for the best results in future that over-charging should be carefully avoided, the battery under present conditions of operation being brought to a fully charged condition only once weekly and that at such times as the cells are used for buffer purposes it should be arranged that these are discharging slightly and not being subjected to a charging current at very low rates. The possibilities of overcharging are more pronounced when low rates of charge are employed as owing to the reduced gassing arising from the lower rate of charge it is difficult to determine fully charged condition and we consider in the circumstances of operation it would be advisable to err on the side of insufficient charging, particularly where low rates of charge are employed. Our usual directions as regards charging involve the employment of a rate as near as possible to the normal and continuation until free gassing has been noted for approximately fifteen to twenty minutes. We advise that straightening of the buckled plates should receive your early attention as otherwise there are possibilities of short circuiting and we shall be pleased, if you so desire, to quote you for carrying out these repairs. Trusting this report gives you all the information you require, We remain, Yours faithfully, FOR PRITCHETT & GOLD and E.P.S. CO LD ENG/B/4 | ||