The remarkable mystery of the elusive dry-cell

Some years ago we were road-testing a 3-litre six-cylinder Rover and in the course of our report mentioned that one of its several refinements was a separate little battery, or dry-cell, to energise its electric clock. The idea appeared to be that if the car’s main battery had to be disconnected the clock would not stop and require re-setting after the battery had been reconnected. When writing-up Kienzle car clocks at a later date we mentioned this apparently sensible Rover feature and were immediately taken to task by Kienzle’s representatives, who were incensed that we should have inferred that their clocks required a separate battery to re-start them if for any reason they were stopped, although this, they advised us, was the purpose of such a battery if used with inferior clocks. Furthermore, they informed us that the Managing Director of the Rover Company had told them that at no time had a Rover car used a separate battery, whether for electrically-wound or all-electric clocks. So we were obliged to publish their admonishment by way of an apology.

But the matter remained niggling in our mind. Admittedly, more recent Rovers were the first British cars to he fitted with the now well-known Kienzle clocks, which we are willing to agree are self-starting, even if they can become useless from congealed lubricant if left idle for an unreasonably long period. But we were sure we remembered the handbook of the 1966 Rover 3-litre telling us that the electric clock was run off its own battery, charged from the main battery, although we never located the mysterious little cell. But there is no smoke without a fire and a weekly contemporary had also referred to this separate cell when road-test-reporting on a Mk. III Rover 3-litre.

Alas, no readers came to our support, so there the matter had to be left. Perhaps, we thought, Rover were about to adopt this separate-cell idea when they changed over to the self-starting Kienzle clock and the paragraph concerned was never eradicated from their handbook or catalogue? Moreover, we reflected that however self-starting a Kienzle clock may be, if it has stopped because the car’s main battery has been disconnected or has run down, the car owner will have to re-set it after it has obligingly got going of its own accord. A minor chore, of course, but one which luxury-car owners might object to—how have Rolls-Royce viewed this, one wonders, since clockwork car clocks have gone out of use?

We had so hoped to be able to vindicate the sagacity of Rover in this field by confirming as correct our reference to their separate-battery-driven timepiece. Alas, no go! Yet, in this life, if you wait long enough many things tend to resolve themselves and untidy ends to fall into place. Three years elapsed, and we happened to be glancing through a weekly motor paper. And there, in its correspondence columns, was a letter about clocks on old cars which may appear to be worn out but which only require a new dry battery to bring them back to life. The writer was referring to his 1968 Sunbeam Rapier, which had a small Mallory RM dry battery beneath the facia to energise its clock, the life of the cell being some 2 1/2-years. We mention this because it may help those who buy a used Rapier to get the clock going and because, if any reader of Motor Sport can tell us of a Rover (or any other cars) with a similar arrangement, the Editorial cup-of-happiness will overflow.—W. B.