Cable length between components

Hi guys, I’m about to embark on my first DIY build.

I need advice on cable length, as in what affects what electronically. If for example I wanted to relocate certain parts to the front, or in a backpack. You get the idea.

My main concerns being resistance and spikes/surges.

So, how much does electric cable length matter between:

  1. Battery and ESC

  2. ESC and Motors

Could I have:

  1. Two ESCs mounted to the front behind the truck, batteries in the middle and motors at the back?

  2. Two ESCs and batteries at the front and motors at the back?

  3. Two ESCs at the front and batteries in a backpack with a breakaway connection on the board?

  4. Two ESCs and batteries in a backpack with a breakaway connection on the board?

Thanks in advance for any advice.

This information is all here for the taking. Search button. Its a fountain of information if you use it. There are so many different iterations of builds on here that everything that you have just asked is readily available for you if you just research. With 6hrs of reading you haven’t imo done enough. Everyone on here has done the hard yards so members can access practically anything at the touch of a button.

Honestly unless you have like 5 feet of wire in your board for some random reason it does not matter at all. Just use 12 gauge wire for a single motor board and 10 for a dual as a general rule of thumb. Or just do what most people on the forum seem to do and use 10ga throughout. Its only a couple bucks extra.

Thanks for pointing that out. Suppose nothing new under the sun.

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Good info, much appreciated.

Typically you want to keep power to VESC’s and phase wires to the motor as short as possible, I’m not saying only use 3cm of wire just keep it short. Other than that you are pretty free.

Also, don’t use 3 feet of wire to a loop key, if your using one, that can be bad (learned the hard way).

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Ignore me I’ve had a bad day :persevere:

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well you weren’t wrong about the search button…

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True but when magic mike shames you you just have to eat humble pie :joy:

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I’m not eating anything offered to me by a half naked man.

probably the wrong analogy.

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Trust me though the man does know his shit. Listen and heed his words. There are a few guys on here that are a level above the rest of us and you have just been lucky enough to hit the radar of one of them.

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  1. I’m frequently half naked, never in public.
  2. Didn’t mean to shame you, just chilling an answering some questions.
  3. Thanks for the kind words, means a lot.
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As far as I know the only length that is critical is from the BATTERY — to the — ESC. Keep that as short as practical. Even if it means longer motor wires.

Under 12 inches should be fine.

If it has to be long then you can use extra capacitors to compensate.

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time to be objective.

most production boards have the battery and esc’s at each end of the board with no issues and so do 2 of my own builds again with no issues. It seems the length of your standard board will not cause problems with cable length but as for the whole back pack scenario then you’ve got me there.
The only issues I’ve read about are the distance between battery and esc’s so keep them within your boards dimensions and there shouldn’t be an issue. If you are connecting components over distance then resistance is something to be avoided and the longer your wiring the greater the resistance so if you are going to be spreading things out then make sure that the cabling used compensates for that. Bigger the better. keep the current flowing man!

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I don’t understand why battery wire is “critical”? as long as you have the correct gauge wire (thick enough to carry your desire amperage), the copper wire resistance is basically insignificant at this length. if anything you shouldn’t have long motor phase wire as it would affect the permutation of the ESC when your motor at high rpm.

http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/wirega.html

I’m on @mmaner side on this one.

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It’s not about resistance, its about inductive load and voltage spikes.

Long DC power wires can become inductors which increase the severity of voltage spikes. The large caps on the esc is to smooth out the voltage spikes.

If your caps are too small or the wires too long the voltage spikes will kill the esc over time.

So if the ESC and batteries are close together, how would distance from the ESC to the motors affect the performance?

Which is irrelevant over the distance he is talking about. Unless we are getting into the backpack scenario and then I will say again why?

What you think would be the right size of capacitors for a usual mtb set up. Batteries in the middle of the deck, esc on the end, cables about 50cm (routed over the binding add some length too). 12s battery and let’s say 5ah. Is there an easy way to calculate?