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 from The Chloride Electrical Storage Company detailing the specifications for a 6-XHR11-LL battery.
| Identifier | ExFiles\Box 58\4\ Scan130 | |
| Date | 18th September 1933 guessed | |
| -2- THE CHLORIDE ELECTRICAL STORAGE COMPANY LIMITED Messrs.Rolls-Royce, Ltd. 6-XHR11-LL type with 7/16" plate pitch, so that you will be able to compare this with the data given for the same type with ½" plate pitch in our letter of the 4th instant. Battery type 6-XHR11-LL with 7/16" plate pitch. Assembly - Monobloc ebonite container with or without moulded ebonite cover. Intercell Connections - Lead-coated copper bolted to terminal pillars. Alternatively solid lead connectors burned integral to the terminal pillars could be employed, in which case the fitting of our standard XC13 elements to the container would be facilitated as it would not be necessary to modify the existing cable ends. Separation - Wood and ebonite. Overall Dimensions - 17 9/16" long x 6¾" wide x 9 9/16" high without cover, or 10⅜" high with cover. Weight (without cover) 67 lbs. dry, or 75 lbs. with acid and charged. Weight of cover 3 lbs. Capacity - 72.5 ampere-hours in 20 hours to 1.80 volts per cell. Thickness of positive plates - ⅛". " " negative " - ⅛". Plate pitch - 7/16". Mud space - 1¼". In reply to the third paragraph of your letter, the batteries type 6-XHR9-LL supplied for the Bentley chassis could be fitted with our standard XCM11 elements as emergency replacements, if necessary. It is not possible to allocate a definite working life in proportion to the thickness of the plates, but it is reasonable to assume that a 5/32" thick plate will last very considerably longer than a 3/32" plate, and again longer than a ⅛" plate. Under the conditions described, including the constant voltage vibrator control, we would expect a life of at least 3 years from ⅛" plates. That obtained from plates 3/32" thick might be taken as 2 years minimum, but there would doubtless be many instances where batteries would last much longer than the periods mentioned. Yours faithfully, THE CHLORIDE ELECTRICAL STORAGE COMPANY LTD. E.C. Mckinnon Chief Engineer | ||