Determining Wire Gauge

Hey,

I'm running a 48V battery to my ME0909 motor and KDZ48401 controller. Continious current draw is 100A and peak draw is 300A for 30 seconds. My longest wire length is approximately 1.5m (from battery+ to one motor connection). I also have a 400A fuse. It's for an electric go-kart

Initially, I was thinking of using 2/0 AWG wiring. However, would 4AWG be fine for this? My main concerns are that - will it be able to cope with 300A for 30 seconds and will the wire not melt before breaking the fuse at 400A?
I'd also like to know your train of thought in determining suitable wire gauge, there seems to be so many different tables, methods online.

Extra Info:
4 AWG seems fine from what I've seen on most sites like this

My only concern is that, it's stated for 100A. How do I deal with the fact that there is a 300A peak for 30 seconds.

I would use the #4AWG, fine stranded copper with good temperature rated insulation, like welding cable. But fuse for the wire capacity, not the controller. Use a regular, not fast blow, fuse. A quality fuse will have a amp/time chart. Check it out. Also consider battery capacity and C-rate. It's likely the Kelly is over rated and could not abuse #4 cable anyway.

Regards,

major

The length are pretty short so not talking a huge weight and cost saving by going smaller... Split the difference and go 2ga?

The longest single wire piece is 1.5m and thats connecting battery + to motor (its not a full loop length - just one segment of wire).
Alright, so 2 AWG vs 4 AWG? Which one?

I'm using this fuse:
http://kellycontroller.com/ane-400a-fuse-p-199.html

Would the 400A fuse be okay? The wiring won't melt or anything right before the fuse blows?

Always go for the fattest wire your setup can handle, you're only limited by the size of the terminals on your hardware.

0 and 2 awg are awesome for flowing loads of current but if you can't get the right connector or ring terminal to fit then, and only then step down a gauge.

2WheelsMovesTheSoul said:

Always go for the fattest wire your setup can handle, you're only limited by the size of the terminals on your hardware.

0 and 2 awg are awesome for flowing loads of current but if you can't get the right connector or ring terminal to fit then, and only then step down a gauge.

Click to expand...

The hardware has no lugs on it. I'll be buying lugs depending on what wire gauge I buy.
There's a big price difference between 2/0 and 4. I'd prefer to buy 4 AWG but I need to know if it's capable of handling that 300A for 30 seconds and if it won't melt before my fuse trips at 400A. I can't seem to find answers to these.

#4 AWG copper will rise 35°C in 31.65 seconds at 300 amperes. Should be well within insulation rating for a good quality cable. Details here. http://nepsi.com/resources/calculators/short-time-current-rating-of-conductor.htm

major said:

#4 AWG copper will rise 35°C in 31.65 seconds at 300 amperes. Should be well within insulation rating for a good quality cable. Details here. http://nepsi.com/resources/calculators/short-time-current-rating-of-conductor.htm

Click to expand...

https://www.ebay.co.uk/itm/25mm2-Black-Red-110-A-Amps-Flexible-PVC-Battery-Welding-Cable-FREE-LUG-PER-METRE/192371086353
Do these seem okay?

Is operating at a higher voltage an option?

wturber said:

Is operating at a higher voltage an option?

Click to expand...

Not really.

This page suggests that 4 gauge may be OK. Me thinks we need someone with practical experience at these power levels. And that sure ain't me.

https://www.evdrives.com/category_s/4021.htm

n1866878 said:

major said:

#4 AWG copper will rise 35°C in 31.65 seconds at 300 amperes. Should be well within insulation rating for a good quality cable. Details here. http://nepsi.com/resources/calculators/short-time-current-rating-of-conductor.htm

Click to expand...

https://www.ebay.co.uk/itm/25mm2-Black-Red-110-A-Amps-Flexible-PVC-Battery-Welding-Cable-FREE-LUG-PER-METRE/192371086353
Do these seem okay?

Click to expand...

Get the specs. Temperature, low and high. Voltage.

Helps if you put your location on user profile.

2 awg is awesome for flowing loads of current but if you can't get the right connector or ring terminal to fit...

Click to expand...

Depending on a variety of issues, sometimes you can split the copper strand bundle and use two slightly smaller connector sets. It may not be ideal, but it can be a handy option. For these motorcycle-level high currents, crimped connectors are preferred due to hot spots melting solder on occasion.

If you decide to make your own lugs from copper rod, specify C14500 tellurium copper. Onlinemetals.com has it, among others...