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).
Letter detailing improvements to the 'Bull Dog' battery and recommending its use for the 40/50 HP car.
| Identifier | WestWitteringFiles\G\October1921\ Scan14 | |
| Date | 8th October 1921 | |
| R.R. 235A (100 T) (S.H. 798, 10-12-20) G 2947 October 8th 1921. -3- Contd. Mr. Birkitt took one or two samples of these new grids. 3. The plates have small feet for resting on the bottom of the cell and this secures the independent support of the positive and negative plates and greatly reduces the chance of short circuiting at these points. 4. The separators have ribs on each side thus giving better circulation of acid and increasing by 50% the amount of free acid. We consider there is not sufficient acid in the American type (we have to produce it because of the replacement business where dimensions have to be kept to). 5. The separators are now cut so as to ensure having a solid rib at each end. If the edge of the separator happens to be the thin web it makes it easier for a curling plate to short circuit on to its neighbour. 6. The cell containers are now made of material which will not crack or split and leakage is almost impossible. is The H.D.E. type of battery with the above improvements/now called by us "The Bull Dog" battery and we believe it represents the best battery at present on the market. For the 40/50 H.P. car we recommend "The Bull Dog" type B.D.11 which has a capacity of about 65 to 70 ampere hours. If you are satisfied with the report on the H.D.E.13, we are quite safe in saying the improved "Bull Dog" type is in every way better. Hoping the above information will be of use to you, We are, Yours faithfully, PETO & RADFORD, (Sgd) G.R.N. Minchin. | ||