simulate this circuit – Schematic created using CircuitLab
- V1 is a beefy battery - it will happily provide 1000A or more;
- RLY1 is a beefy contactor, the LEV200 series, rated for 500+A, 12-900VDC;
- C1 is the capacitor in question.
When closing the contactor, the inrush current to energise C1 is capable of welding the main contacts. Of course if C1's capacitance is small enough the issue subsides to manageable levels. This amount of capacitance is what I want to compute, if possible. A crude/conservative figure is reasonable given that the datasheet does not mention anything about (non-precharged) capacitive loads.
Ideally there are many methods to avoid the welding even if C1 is large (precharging, adding series inductor and/or NTC resistor), but my question pertains to the above model only, I want to know when these measures are needed.
EDIT: As per Macrus Müller's comment, the source impedance of V1 is very important, it is approx. less than 0.1 ohms.