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).
Exide and De Martis batteries, detailing their construction and performance claims.
| Identifier | WestWitteringFiles\F\March1921\ Scan33 | |
| Date | 7th March 1921 | |
| Contd. -4- EFC3/T7.3.21. We think that both this battery and the new Exide battery should give very good results in service. eliminating entirely, we anticipate, the short circuit failures due to buckling which we have experienced. We already have good results reported from the Test Dept. of one of the experimental batteries fitted with perforated ebonite sheets. X4206 U.S.A. Exide 6-LXR-91- We have received a U.S.A. Exide battery which has burnt up connections, but otherwise is very similar to the British Exide. The other points of difference are in the dimensions and in the fact that all cells are sealed into the case in one mass. The method of fixing the lugs through the cell lid{A. J. Lidsey} and the vents are the same as the British Exide. X3629 De Martis. We have received from the De Martis Accumulator Co. one of their 12 volt 70 ampere-hour batteries. Extraordinary claims are made for these batteries as follows :- 1. It can be charged and discharged at very high rates without buckling plates. 2. Can be discharged down to 0 volts without any harm to plates. 3. Can be left discharged for any length of time without damaging the accumulator. 4. Whatever the conditions may be, whether through prolonged discharge or through carelessness, the De Martis accumulator will not sulphate. 5. At equal weight and according to the rate of discharge the De Martis accumulator has a capacity of 40 to 100 percent greater than any other accumulator. 6. It possesses very low internal resistance, constant voltage during discharge, and high current output. 7. It is fool proof and solves the problem of electric traction on Lorries, Railways and Tramways etc., Starting and Lighting on Petrol Cars. 8. It can be normally completely charged in two hours - 60 per cent of the actual capacity can be put in in only 15 minutes. 9. For the same capacity they cost less than any other cell 10. They are the lightest, most practical and efficient on the market, non-sulphating, high capacity, rapid charges, and discharges and having a long life and are now in practical use by many Continental Firms. | ||