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).
Modifications to Exide and Tudor batteries to prevent corrosion on terminal lugs.
| Identifier | WestWitteringFiles\G\June1921\ Scan108 | |
| Date | 23th June 1921 | |
| To R & E from EFC. c. to CJ. c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} X.607 - RE EXIDE AND TUDOR BATTERIES X.4053 X.4283. X.979 X.4288 We are sending you under separate cover four cell lids with stoppers, terminal lugs, terminal nuts, etc. No.1 shows the arrangement on the original 6 EXE5 Exide batteries used on the 40/50 chassis previous to any modifications. This as you will see is fitted with lead coated brass washers under the nuts, the space unde-r the washers round the lug being filled with grease. A certain amount of corrosion was experienced from these brass washers, the corrosive mess spreading radially from the brass washers on the positive lugs in the form of sheaves. We pointed this out to the Chloride Company and got them to replace these brass washers with hard antimonial lead washers as seen on sample No.2. No.2. shows the type of terminal lug provided on batteries to which the modifications of flexible connecting links, central stay bolt and perforated ebonite separator sheets had been added. This modification eliminated the corrosion to which we refer. It has not appeared that there is any appreciable tendency for corrosion to start from the nuts or the screwed lug, as it did from the brass washers under the nuts. We therefore think this arrangement No.2 is good. The connection to the flat cell to cell connecting strip or to the cable terminal is made between two of the hexagon nuts. At the same time the nut above the strip is being tightened, the lower nut cannot turn and therefore the electrical connection is made particularly between these two nuts -and the screwed lug, without at the same time putting excessive compression on the cell lid{A. J. Lidsey} and rubber washer. Finally the top lock nut is put on. Our experience has shown that this electrical connection is satisfactory. No3. In the latest lot of batteries that the Chloride Company have supplied to us they have made what the consider to be a further improvement which is represented by sample No. 3. It will be seen that in this case the lug passing through the cell is heavier, and the joint at the cell lid{A. J. Lidsey} is made by screwing the hard antimonial lead nut on to a coarse antimonial & lead thread of larger diameter than the thread on the brass. Then they put on a brass washer Contd. | ||