This article on Zundapp Bella Regulators was written care of Bert and Zundapp Club UK The Bella holds a mechanical regulator from factory. It truly is a little mechanical wonder created by the firm Bosch. It holds an electromagnet in the form of a small coil that allows the regulator to charge from a certain voltage to prevent the battery from emptying out as the regulator is connected to ground. This coil is calibrated to close the charging contact just above the maximum charge of the battery at rest. Another set of points can be calibrated to set a minimum voltage when the regulator will send through current to the matter and a maximum at which point the charging stops. These units should last at least 60.000 miles, but over time the two sets of contact points can wear out or the metal springs used to calibrate the electromagnet can get metal fatigue or vibrate loose. When this happens, you will usually find that the red charging light may come on [...]