My no BMS layout - Please help

Hi guys. I have been loitering an planning for a while now and hopefully the board should arrive today for my build (the Pork Chop Express) anyway. I have been inspired by @whitepony to leave a BMS out of my build (partly for cost but also because I’m looking for a simple rugged build to use for commuting so the less things that could go wrong the better!

Please could someone take a look at my layout below and just advise that I haven’t made any huge mistakes? I am planning on using 40 Samsung 25R batterys in to this 10s4p layout. I will still use balance cables/plug so that the cells can be periodically checked when I take the shell off.

I wanted to make a pack that is a little more compact than laying them flat. I have thought about doubling up the cells as below. Would this also work? (dashed line on the top diagram is where the “fold” would be.

Finally I have some questions about the gauge of the balance and main power cables? What should I use for each? Plan is to stay with single drive. I am planning on doubling up the Nickel (0.25mm) on the series connector. Would this be sufficient or would wire reinforcement be better?

Thanks for any advice you can give!


what is round button-like symbol between B6 and B10 ?

Charger plug in possibly

Sorry - I should have labeled that - yes charger port probably a 5.5mm socket.

ok so you will use Antispark plug as ON/OFF switch correct?

Yes that is the plan - I want to print a loop to hold/support the loop of wire as it comes out and goes back in - then I will use a spare XT90 half attached to my keys to make sure I don’t lose it.

I should also ask what I should look out for when buying a charger. I know that the Evolve one used by Whitepony cuts off at 41v is this usual? Will any 36v charger have a 41 or 42v cutoff?

Something like this for example?

Mine is wired the same way , i have the second half of the Anti spark attached to the enclosure by a strong nylon string . So i just plug in and out for my ON/OFF.

…in pucture it is not inserted all the way

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I like that. Really tidy with the mesh from enclosure to motor.

Most 36V chargers will stop at 42V, I got a charger from “MODIARY” like whitepony’s , I emailed them and asked if they could change end charge to 41V and they did without charge !

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I wouldn’t have even thought to do that. I think I’ll drop my charger order with the EU group buy and try the same.

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the only difference in my wiring is the Voltmeter, mine is a very small one from “DROK” it has 3 wires,… 2 for powering it, which are tapped onto the wires powering the “Reciever”… and 1 wire reads the Battery Pack V on the POS side

maybe add some protection between cells so they dont have abrasion between them and short and add protective donuts to the positive terminal

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Yes I was planning on positive terminal rings and hot gluing the packs together. My deck should be very low flex so hopefully this will be enough to stop rubbing.

I am hoping to ABS heat form an enclosure which I will do once I I have properly planned the battery / vesc etc layout. Having seen how low @Randyc1 rides with one layer I may have to follow suit. (otherwise Ill be top mounthing on a drop thru)

I actually think I might have one of those from my drone building. Was a voltmeter rather than a battery % but maybe that would be a way to go. That is 3 wires so would be wired same will have to check it is a 5v to power it.

yes the Drok voltmeter can be powered from 5-30V i think,… then the other wire is good to read up to 100V

I rather V reading rather than %, this way you know excactly the Voltage

Perfect. Looks like I might be on to a winner with this layout then. Just found your build - great work!

Thank you.

What guage wire did you use for the main leads and balance leads? I am thinking 10awg? for main leads?

Yes main leads 10g

Balance 20g

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