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 failure analysis and condition of a P & R TBD7/7 battery.
| Identifier | WestWitteringFiles\L\July1924-September1924\ Scan106 | |
| Date | 16th July 1924 | |
| EFC. JB.50. X.4414P. RE TESTS ON P & R TBD7/7 BATTERY. No.2 cell has apparently failed in this battery by short circuit as no voltage shows when on charge, and is very sulphated. Before it was put in the E.M.S. it had completed 7,595 miles on the road and has been in the E.M.S. for a period of 8 months, broken by one low rate discharge which was taken on 10.3.24. and gave 41.8 ampere hours. Is this battery now to be opened up for examination and report? JB.52. Re Failure of P & R TBD7/7 (103) During the dismantling of this battery notes were taken on its condition and are as follows. General. The wood box was rotted right through by the acid but no sign of a leak could be found. The sealing compound was cracked and it appears that acid had run through this and between the cells and consequently rotted the box, there being no way in which the acid could get free. The cell to cell connections were good and sound, no sign of corrosion could be found. No.2 Cell. All the plates were sulphated and had also shed a good amount of active material. The paste was fairly soft in all the plates but was firm and intact. The plate grids were also sound and showed no signs of buckling at all. The separators were mainly in a good condition, but were easily broken if roughly handled. The plates had sunk into the supporting ribs about 1/8" possibly due to softening with heat. A large amount of sediment had collected in the bottom which reached up to the plates and therefore caused short circuit. It must be understood that this battery has been subject to a large amount of overcharging. The cell cases are very strong and durable and are a more substantial job than the C.A.V. Willard or the Exide. The life of this battery would have been much longer if more sediment room had been allowed in the cell case. The age of this battery is 21 months. GJ. | ||