Welcome Phil.
I plug the charger in if the car is not going to be used for 10 days or more. I use the cigarette lighter socket under the dash which I feel is adequate for trickle charging, but others feel wiring in a direct fused connection is better.

I have a clock and a radio, both of which have a small consumption, as well as the immobiliser (ECU).

On the issue of flat batteries: I run with the headlights on all the time (actually a legal requirement, or at least daytime running lights, outside built up areas in Italy) and even though the headlights go off when the ignition is off the parking lights stay on. I have twice run the battery down so I now have a beeper fitted so that if the lights are on and the key at "Off" the beeper sounds. As the battery is under the parcel shelf I started the car by connecting to the power input to the starter motor.

Peter

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