Hello! I found how to calculate here: http://liionbms.com/php/precharge.php But the problem is, that when I used online calculator, it gives me that with resistance 531, my charging time to 288V will be about 2.3 seconds instead 5 seconds, that I need. Online calculator here: http://mustcalculate.com/electronic...p?vfrom=0&vto=288&vs=320&c=1880u&r=531&time=5 We have: Capacity that we need to charge in controller: C=1880uF or 0.00188F Battery nominal voltage: U=320V Time, that is needed to charge controller capacitors to 90% of the nominal battery voltage: t=5s We need: 90% from 320V Needed resistance R in ohms Maximum current during precharge Energy E in joules Power P in watts Peak power PPeak in watts 1. U1=(320V/100)*90%=288 V 2. R=t/C/S=5s/0.00188/5=531 ohms 3. I=U/R=320/531=0.6 A 4. E=(C*V2)/2=(0.00188*2882)/2=78 Joules 5. P=E2/T=782/5=15,6 W 6. PPeak=U2/R=2882/531=156 W Is everyithing correct? What is that 5 (S) in 2nd calculation? Thank you!