During my first trip I tried to charge my devices directly from the T4s’ main battery. Over usage would have resulted in a dead battery causing the car not to start at all, which is why I needed some kind of indicator, if the battery is capable of charging my stuff: a voltmeter.
This is why this afternoon I added one into the main console, nothing really special, but as the first adjustment worth mentioning.
Also if the power consumption of the measurement devices is minimal, I added a switch to the setup as the 12V cigarette lighter seems to hot wired to the battery which would cause the battery to discharge while the measurements would be taken. Furthermore measurements during driving wouldn’t be really helpful as the tend to fluctuate depending on enabled consuming devices like headlights or windscreen wipers. It’s a simple setup, but I like switches that increase the feeling of sitting in a cockpit 🙂