Help confirming Pre Charge Technical

Hi,

I am installing a pre charge circuit on my 72v ebike build. Battery is 20s10p of Sony VTC6. So capable of 150amps+. So I want to avoid large sparks on connecting the battery.

Can you please confirm a few things.

Does the resistor come before the switch? Battery>Resistor>Switch>Controller.

What switch is suitable. What specifications should I look for. (I have blown up 1 in the past and am now scared )

What size Awg should I use for pre-charge circuit. Heard that 14awg is suitable, but want to go as thin as possible.

Plan on using a 1000ohm 10watt resistor. Particular one in the link.
https://au.element14.com/arcol/hs10-1k-j/resistor-wirewound-1kohm-5-axial/dp/2478137

bump

hussman said:

Does the resistor come before the switch? Battery>Resistor>Switch>Controller.

Click to expand...

Resistor goes ACROSS the main power switch. You then have a second precharge switch (usually a button) that you push to charge it up.

What switch is suitable. What specifications should I look for. (I have blown up 1 in the past and am now scared )

Click to expand...

I=V/R. So if you have a 10 ohm precharge resistor and a 72 volt battery, you need a 7.2 amp switch. And of course it must be rated for at least 84 volts. (max charge voltage)

What size Awg should I use for pre-charge circuit. Heard that 14awg is suitable, but want to go as thin as possible.

Click to expand...

See above. Figure out what gauge you need for the current you want to handle to be 100% safe. You can definitely go thinner since you WANT extra resistance; as long as the wire does not melt (i.e. don't use 30 gauge) it will still work just fine. If you have some spare 18 gauge for example you should be good.

Plan on using a 1000ohm 10watt resistor. Particular one in the link.

Click to expand...

That might take a long time to charge up. Might want to consider a lower resistance.