I am laying out my board before making my enclosure, I thought up 3 compartments. 2 seperate battery compartments and 1 for the electronics. I have not seen this on the forum yet and am wondering if I’m overlooking something. 
What batteries should I get for my dual motor build.
Should I go with two of these:
But I think they need a higher c rating.
Or these batteries in the video at 2:35.
Does anyone know what those batteries are?
Thanks.
You need to use the search button, and your resources.
The youtube videos description has an amazon link for the batteries
Those lipos are plenty fine if youre a normal rider, but instead of the available ~190A(per lipo), use less to preserve the batteries health. Two will get you amazing discharge and great range. I doubt you’ll ever experience voltage sag
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Dude you asked basically the same question about the deck used in a YouTube video this morning and I showed you it was already answered in the comments too.
Do yourself and everyone here a favor and please search before asking. I understand it’s a large and confusing new field but there is a plethora of information just a search away.
But the batteries in the description of the video is some other batteries than in the video.
Freewheeling makes energy that lights up Vesc and possibly much worse if go too fast w no battery
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Alright, freewheeling regenerates practically zero energy. You will not charge your battery from freewheeling.
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Is there any danger associated with freewheeling a powered board that is dead? (after the 3.0V cell cutoff from the BMS)
Coasting with a dead battery is fine as far as I know as long as it’s there. I have to get a blue tooth logger again but does coasting at low or high speed not charge at all? If ur in danger of blowing up ur stuff even coasting around without a battery it makes sense it must be charging a little. Damn gotta get one them loggers for iPhone going.
Finally, not possible, as the shaft it too short for my need !
I have to make custom one ^^ but it will be the same thing > I will ask to a workshop 
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Could an electrical engineer or BMS guru please check my wiring diagram?
Its 12s1p Lipo pack made from 6 2s packs. The BMS can do 14s but will also work at 12s. I am only using it for charging.
The 3 wires coming out of the batteries is the balance plug that comes on them.
Thanks.
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Looks good to me.
That looks like a smart bms, right? They have some pins not used on the jst plug, but as there no cables coming out you can’t make anything wrong in this place.
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Yes. 20A 14s version.
My cheapo 12s 4amp charger took a crap and I don’t want to use my 8amp all the time.
I’m looking for feedback from those who own this charger:
US $38.22 32%OFF | 50.4V 4A Charger 50.4V 4A Li-ion Charger for 44.4V 12S Electric Bike lithium Battery Aluminum shell With fan
Yes, I agree with @Andy87 it looks good. Leave B13 and B14 unhooked.
These are good fuses if you don’t charge over 4A
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What’s bad about the 8A charger?
The charge jacks people typically use (5.5mm x 2.1mm barrel plugs) are only rated to 5A, and charging faster slightly reduces battery lifetime.
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Are the effects of 8a noticeable on 4p 30Q?