Inspection and comparison of a salvaged German 'Varta' battery from a Heinkel bomber.
| Identifier | ExFiles\Box 164\2\ img025 | |
| Date | 29th February 1940 | |
| Rm {William Robotham - Chief Engineer} / Childs 6021 To: [Struck through] Copies to: Sg. {Arthur F. Sidgreaves - MD} Lpr Hsv Derv Lr. {Mr Ellor} Rm. {William Robotham - Chief Engineer} En. LP {Mr Lappin} /Lox Details of German battery removed from Heinkel aircraft. At the invitation of Messrs.Pato & Radfors I visited their Works on the 27th instant to inspect a German 'Varta' battery salvaged from a 'Heinkel' bomber. Whilst there, our development with extra thin plate aircraft batteries was also discussed. A full description of the battery is attached herewith. Interesting points are :- (a) The ampere-hour weight ratio is slightly better than the existing Air Ministry batteries. (b) The internal resistance is less by approximately 30%. This is achieved by the use of .050" thick plates as compared with .062" on the Air Ministry type and by the use of copper cored cell pillars. (c) The plates are apparently stamped out of sheet Antimonial Lead and pasted all by machinery. Whilst this process gives much less life than the British method of die casting the plates and hand pasting them, the rate of production is increased and the cost reduced. As a wartime measure this would be justifiable assuming the average life of the battery to be 6 months. (d) The specific gravity of the Electrolyte is 1.307 as compared with 1.270 on the Air Ministry type. This again will reduce the internal resistance and improve high rate discharge but at the expense of battery life. With regard to (b) our new thin plate batteries using .045" plates will be much better than the Heinkel battery and the ampere-hour capacity will be higher. | ||
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).