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 discussing experimental battery comparisons and specifications for separators and electrolyte levels.
| Identifier | ExFiles\Box 54\1\ Scan098 | |
| Date | 16th April 1926 | |
| X4617P EFCl/T. 16th April, 1926. Mr. C.R.N. Minchin, 50, Grosvenor Gardens, London, S.W.1. X4655 Dear Mr. Minchin, Thank you for your three letters of yesterday's date. It is quite true, as you say, that it is difficult to base reliable conclusions on the experimental comparison of the whole Exide and the whole P & R battery, report of which we sent to you. We have not heard anything here about the sandwich battery on Commander Briggs' car, but I understand this car is returning very shortly when we shall probably hear all about it, and I will let you know about this in due course. With reference to the question of separators. We are definitely agreed to the ribbing of the separators on both sides. Also we think it is a good thing to allow the ebonite separators to extend a little bit over the edges of the plates, but I think it is doubtful whether it is the right thing to carry them sufficiently above the tops of the plates as to form a guide as to the level of the electrolyte. Instead of using this as a guide for the level of the electrolyte, i.e. instead of saying that the level of electrolyte should be up to the tops of these separators, I think we should say, having arranged for the ebonite to stand a little bit above the plates, that the electrolyte must always at least cover the tops of the separators, and in general be maintained to a depth of 1/4" above them. If we only say "keep the acid up to the level of the separators" it appears to me that the tendency will be to think that they have got a bit in hand and it doesn't matter if it falls a bit, in which case it may reach the condition of not covering the plates. Contd. | ||