- #1

t00mas

- 2

- 1

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

- 90% from 320V
- Needed resistance R in ohms
- Maximum current during precharge
- Energy E in joules
- Power P in watts
- Peak power P
_{Peak}in watts

2. R=t/C/S=5s/0.00188/5=531 ohms

3. I=U/R=320/531=0.6 A

4. E=(C*V

^{2})/2=(0.00188*288

^{2})/2=78 Joules

5. P=E

^{2}/T=78

^{2}/5=15,6 W

6. P

_{Peak}=U

^{2}/R=288

^{2}/531=156 W

Is everyithing correct? What is that 5 (S) in 2nd calculation?

Thank you!