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).
Lead-acid battery plate chemistry, construction, and maintenance.
| Identifier | ExFiles\Box 54\1\ Scan074 | |
| Date | 9th December 1925 guessed | |
| -2- Contd. amount of active material to keep up the capacity, and I do think there may be something to be gained by experimenting on means by which the positive active material can definitely be kept in position, and at the same time in effective electrical contact - and that of course is important. I know from an experiment I have recently made of reversing small test tube Plante positives to negatives and vice versa, that a good deal of chocolate oxide will remain mechanically as scale on the negative plates for a considerable period and yet not be in electrical contact with the plate, the core of which is definitely negative. From my experience it is very easy to form up positive elements into an active electrical condition, but very much more difficult to get a correct negative, and I am not sure, even if you get the positives to last indefinitely (by retaining their paste), that the negatives would, though I think they would, i.e. if properly treated. They certainly will not, if the battery is not properly treated, and that is very important for the negatives, and I think, bar overcharging, of very little importance for the positives. Active negative plates, by hook or crook, will get oxygen from somewhere, in my opinion, and that is why I say it is so desirable as to be almost necessary, to give batteries freshening charges periodically (to reduce any oxide). Of course this is not so important when you have low discharge rate thick block plates, like the WH 24-volt Exide H.T. battery, because the proportion of surface to volume is very much less, and proportionately less oxidation takes place in a given time. So if at the same time as keeping all the positive paste in position we could by some means keep oxygen (except the fixed oxygen in the electrolyte), from the negatives,(it is fairly certain that there must be free oxygen from the atmosphere in the solution) that would keep the battery in very good condition. The six-volt Exide battery which I have at home and of which I spoke, has a good deal of deposit - about as much as you would expect in six years correct use, at any rate in a battery with paste of ordinary hardness. Contd. | ||