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).
Special 12-volt battery fitted to Mr. Minchin's car.
| Identifier | ExFiles\Box 164\2\ img004 | |
| Date | 10th February 1939 | |
| REPORT ON SPECIAL 12 volt BATTERY FITTED TO MR. MINCHIN'S CAR. When Mr. Minchin took delivery of his present Bentley car it was decided for experimental purposes to fit it with a composite battery. Three of the cells had 9 plate elements with 1/8" thick positive plates and 3/32" thick negative plates, and the remaining three had 11 plate elements with 3/32" thick positive and negative plates. The battery was fitted in May 1935 and was finally taken out of service in December 1938. During the time it was in service the battery was taken off on one occasion and returned to Peto & Radford works for examination. This was in December 1937, when the battery was reported to be in a rather "low" condition. It was then found to be merely in need of extra charging and suitable adjustment were accordingly made in the dynamo output to overcome the trouble. In the following schedule particulars of the ampere-hour capacity and condition of the plates are given for the two types of elements fitted:- BGD. 9-plate GLD11 plate Type and number of plates per cell. Dimensions of positive plates 5 5/16"x4 5/8"x1/8" 5.11/16"x4 5/8"x3/32" " " negative " 3/32" 5.11/16"x4 5/8"x3/32" Actual Capacity at 20 hour rate 65.6 amp.hrs. 70 amp. hrs. when new Condition after 2 years 8 months (December 1937) Capacity at 20 hour rate 67.4 amp.hrs 70.0 amp. hrs. Weight of sediment per cell 1 1/2 ozs. 3/4 oz. Vertical growth of positive 1/32" 1/8" plates Horizontal growth of positive 1/16" 3/16" plates | ||