Chris:
Good advice.
Some vehicles (Land Rover Discovery II) apparently have ultrasensitive electronics. LR even suggests removing the battery completely for charging to then jump start the truck!. Years ago I jumped the battery in my bmw and a few hundred miles later I was buying a remanufactured ECU (BMW speak for DME). On BMWs you have to use the hot " +" post on the firewall and ground to the engine (hook near manifold used to hoist engine) as the battery is in trunk. Obviously, I did not do this.
However, when I alter replaced the chip in the ECU with a performance one (requires removal of unit) I had a static free matt and workstation at work and everything went smoothly.
Live and learn.
Jase