MD2020 - voltage regulator, battery and charge test

In some of my videos I had a charging alarm when starting up the engine, it is due to no charging at idle so in this video I look into the problem and try to find out why it doesn't charge. To check the health of the 12V battery the voltage must not go under 10V. when the starter is engaged, in my case the volt is around 11 Volts so the battery is good.