I'm designing a system to power up my vehicle with 12vDC and I have 8 motors each draws 25A at max and they are not expected to work always at the same time, meaning that in the maximum case 6 of them working 70% and 2 of them works 100%, so my question is that what power supply should I choose to be enough to power the vehicle up like what power rating should it be ? 1kw or 2kw ? And why ? I mean if there is any equation or calculation method to use ? Please help me with that.
Power equals voltage times current. One motor therefore has maximum power of 12V * 25A = 300W
6 x 0.7 x 300W = 1260W (1.26kW)
2 x 1.0 x 300W = 600W (0.6kW)
Total: 1860W (1.86kW)
So the maximum power is equal to 1.86kW meaning you need to have a supply power being able to output at least that much (though in reality, at least a bit more).