Judging by the applied ESA logo on the top half of this Swisselectric watch, this is probably an ESA demonstrator, much the same as the other watches with ESA on the dial.

The movement is a standard Landeron 4750 — Landeron was an ESA owned brand — but what makes the watch particularly interesting is the fact that it has an accumulator i.e. a re-chargeable battery; the Lechanché 80 mA re-chargeable cell. The cell was charged via a socket on the left hand side of the case; this socket is covered by a dummy crown when not being used and, when the watch was first sold, it would have been supplied with a spare crown.

Originally, the Lechanché 80 mA re-chargeable cell needed charging every six month but after 50 years, many of these cells only hold a charge for a few weeks. I am fortunate that this one seems to last at least 6 weeks before needing a re-charge. See the Landeron Accumulator page for more information on the device and method to charge these watches.

The watch dates from the early 1960s and although many watches used these Landeron movements, nearly all are powered by conventional WD-4 or WD-5 batteries. The accumulator version of these Landeron-based electric watches did not last very long and, as a result, these watches are very hard to find.

I have a second example of these Landeron Accumulator watches; it is shown on the Landeron Accumulator page.