Dear conversion friends,
When the engine is running, we operate the MultiPlus-1600VA directly from the generator (buffered by starter battery). As soon as the engine is switched off, we switch to the body-battery with a high-power changeover contact (relay). How fast must the switchover take place so that the voltage drop on the AC side of the MultiPlus-1600VA is a maximum of -10%? Assume that the AC side is loaded with 80%.
What do you mean by "maximum -10% voltage drop"? Because the AC voltage is always changing. The AC voltage is measured using rms, over a period of time.
FYI - A UPS can transfer within 2ms - 16ms. How long the inverter can operate without a battery depends upon the point in the AC cycle. Near either peak? Or near the zero-cross? A big difference. Victron might tell you the total input capacitance value or not?
I would not have any dead-time in my switching design. I would put a 200 amp Ideal Diode across the contacts used to connect the house battery = glitch free!
In most EU camper vans, the starterbattery and leisure battery (body-battery) are connected with a 12V cut-off relay when the alternator is running. This ensures that both the starter battery and the leisure battery are charged while driving. When the leisure battery is LFP, you must use a DC-DC charger booster instead of a cut-off relay, in order to properly charge the LFP battery.
On the leisure battery the inverter is connected. So when the alternator would stop running, the inverter will continue to work on the leisure battery, without any interruption on the DC side.
