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).
Report page discussing the reversibility of lead accumulators, temperature effects on batteries, and comparisons with nickel-iron batteries.
Identifier | ExFiles\Box 38\5\ Scan198 | |
Date | 2nd February 1922 guessed | |
-2- Contd. been originally assembled in a partially discharged condition. On charge this sulphate is driven from the plates into the electrolyte, a consequent rise of density resulting. Reversibility of a lead accumulator. We informed Mr. Preston of our experiment of reversing a cell, i.e. charging it the wrong way round, and the result was that we obtained as much capacity one way or the other. He says that this is quite in order and a cell can be reversed in this way and an equal ampere-hour capacity obtained. He pointed out that to reverse a cell and come back to the original condition would be a far more difficult matter, as to do this the negative plates would have to be taken out, washed and dried, before the reversal could be effected. Temperature effect. Mr. Preston laid great stress upon the effect of temperature upon the ampere-hour and watt-hour capacity of a battery. He thinks a temperature should be specified for all battery tests carried out with a view to comparison. He also pointed out to us that the efficiency of the nickel iron battery is very low as compared with that of the lead acid accumulator, this also varying greatly with the temperature of the electrolyte. He pointed out to us that P & R batteries do not come up to their full capacity until about the tenth charge and discharge, this being due to the hardness of the plates which goes to produce longevity of the battery. His theory of the frothing of the celluloid cell is that it is due to camphoric acid being librated by the | ||