Wire size

[brainfarth]

I have a 9" run from my battery to a plug and was wondering if 18ga wire would fit the bill. I ran a few online calculators with mixed results. The BMS has a max 35amp output @ 60v. This is one corner that I dont want to cut.
Thanks for any info on my newb question.
-Mike

 

[Ykick]

I dunno the charts too well but if it were my setup I'd use 12ga. What's the worst that can happen using thicker gauge than you may need?

 

[brainfarth]

My only concern with using thicker wire is ease of connection. I have a limited amount of room for the connection to be made, and if the wire is too rigid, I will have issues plugging things in.

 

[bowlofsalad]

My only concern with using thicker wire is ease of connection. I have a limited amount of room for the connection to be made, and if the wire is too rigid, I will have issues plugging things in.

http://www.powerstream.com/Wire_Size.htm Play around with the calculator at the bottom of this page. The thicker the wire the less resistance the wire will have. I'd probably use thicker stranded wire if you can. Less resistance meas more power gets to where you are trying to get it to and less of that power is converted into heat. Using wire that is too thin for the application almost defeats the purpose. If it were me, I'd use some very thick wire right up until you have no other choice (usually when wires go into a motor).

http://hobbyking.com/hobbyking/store/index.asp This place sells some very flexible stranded wire that would circumvent any issues you may have with wires being too rigid.

 

[Ykick]

My only concern with using thicker wire is ease of connection. I have a limited amount of room for the connection to be made, and if the wire is too rigid, I will have issues plugging things in.

That floppy Silicone 12ga stuff is what I have in mind. Dress easy, fits all my connector terminals, good for high temp. Only downside is it doesn't handle sharp edges very well.

 

[dnmun]

yep, 12 AW would be the minimum to use for 35A. 14 would get warm a little bit i expect.

 

[ricklearned]

I thought wire was sized by current, regardless of the voltage. Around my house 12AWG is used for 20Amps, so 10 or 8 unless you have a very short run.
Note: I reread the OP and 12 Ga should handle a 9 inch run. I had a 30 amp EVSE that used 14 ga inside for some very short connections.

 

[brainfarth]

I found some wire laying around that measured .071" and figured that was close enough. So I took it up and down a steep grade a few times and checked the wire, which was cold to the touch.

And here is what I've been up to:

I found 20 rocker switches with LED's built in for $9.79 http://goo.gl/HftMra
And 20 water proof covers for $4.50 http://goo.gl/jOJeV7
They are for turning on my DC/DC buck converters, one set at 5V for USB stuff and the other is at 12.5v for my heated hand grips and other things that might use that voltage. I bought two different kinds because I was unsure which would work better.. The small one has been running non-stop for months now without any issues. They can be found here http://goo.gl/92LoVw and here http://goo.gl/HBWf6u The little one is quite a bit cheaper now at $1.76 so I might have to buy a few more of them.
The third switch is for future upgrades. And I kept 5 leads for the USB connection for possible data transfer in the future.

And some pics:



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