Disconnecting the battery is a common occurrence on Judith as I do it for storage and as a safety measure when working on anything that doesn’t require the electrical system (which, on a 2CV is most things).
As connecting and disconnecting the negative terminal requires a 10mm spanner and puts stress on the wires I wanted a better and more convenient solution: a battery isolator. Looking around there are various options but, as the secondary earth wire is cast into the negative terminal connector I didn’t really want to use an isolator that required replacing the connector. The one I’ve settled on has both male and female connectors so sits inline with no modifications required.
It consists of two metal plates separated by an isolator and a brass screw. When screwed down the bottom of the nut contacts the top plate and the thread contacts the lower plate completing the circuit.
Fitting to the car was as simple as it looks but I might try and replace the pinch bolt, whilst it shouldn’t need removing very often it does seem to be made of soft steel and the nut sits somewhere between my 12mm and 13mm spanners – the price of a decent replacement is worth the piece of mind.