Hello, there is an indicator in the car that lights up when the battery is discharged. In the quad I do not have such an indicator – but on the ordered digital-tacho a corresponding warning light (only LED and symbol, no technology). Now I wanted to build the circuit behind it myself, but am not quite sure how I can do this most skillfully. It is clear that the LED with the ignition is switched on and then has to be switched off when the LIMA the Battery e load – so far quite simple. But how do I notice that the LIMA load the battery? 1. Possibility: the board voltage exceeds 13,5V (shows that the LIMA works). Ok, that should be feasible — however: should the consumers pull more power on the quad (illumination etc.) than the LIMA supplies, then the battery would discharge but the display would remain dark. 2. Possibility: a diode between LIMA and charging controller, so that no power comes from the battery to the + pole of the battery and d then at the LIMA directly the contact to turn off the display on — problems: the diode would have to have real eggs and also the problem with the too large consumption as at 1. 3. An ampere meter, which can show both positive and negative current. Analogly, there is the yes. Digitally, I have never seen it, but if there is such a circuit, then you only have to pick up the switching contact at the place where the current between LIMA and battery is 0 or just vo n Battery direction LIMA flows… But does anyone know such a (simplified) circuit? 4. ??? Is it even easier?