@tijmen, The way I did it was to simply not hook up the battery negative to the P- terminal. Instead simply wire the VESC (or switch) negative directly to the battery negative. Hope this helps.
I just want to add, even if the max rating of the motor is higher, i doubt you will ever use this much. I would recommend trying it out, before bypassing the BMS.
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So what you’re saying is that when using the system, the batteries would be hooked up directly to the ESC or switch, but when charging the power would go from the BMS, back through the ESC and then into the batteries? And good idea about the max amp draw. The motor I’d be getting (not sure on which one), will most likely only be 5 amps more than the max draw limit of the BMS
@ flatspot is absolutely right, you probably won’t pull that many most of the time. I bought a very cheap bms for now which is only rated at 15amps discharge. So I went ahead and bypassed it. I updated @oriol360’s original post showing how he wired to illustrate how you would bypass the discharging function but still allow for charging of the batteries. No electrons pass through the vesc when charging on the way to the battery. I hope this helps. Forgive my crude MS paint editing methods. 
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Could anyone please advice with the following setup?
I have a 12S setup with 3 lipo’s of 4S. I have this BMS I use a simple 50,4V charger
I only want to use my BMS for charging. Not for discharging.
Is this the correct setup? Will it work correctly?
Also I have a question about the balance leads.
I have a 4S lipo, with a 5-Pin balance connector. The first is red and is off course positioned before the first cell. The last is black and is positioned behind the last cell. The other three are between each cell.
That’s 15 balance wires in total for the Lipo’s
The BMS has 12 balance wires. And 2 negative connectors on board. B- and P-.
The charge port connects to the P-, and the + of battery 3.
I assume that’s why I can discard the red wire from the balance cable from te lipo (the first pin) and use pin 2,3,4,5 from Lipo Nr3 for the first 4 balance wires from the BMS.
As pin 5 from lipo 3 is the same as pin 1 from lipo 2 I can again discard the red wire (pin 1) from lipo nr2’ balance connector en connect pin 2,3,4,5 with the BMS balance cables 5,6,7 and 8.
For the last lipo (lipo one) I can again discard the red balance wire (pin one). Pin 2,3,4 will connect to wire 9,10 and 11 from the BMS.
What should I do with pin 5 from Lipo 1?
- Should I connect this to cable 12 from the balance wires?
- Or to B- of the BMS? If I choose option one, do I need to connect B- to the black main cable of Lipo 1, or could I just ignore that connection?
A 4s Lipo has 5 balance wires: Black = ground color= cell 1 color= cell 2 color= cell 3 Red= cell 4 This is the standard for all Lipos. Black is always ground and Red is always the Last cell in the pack. A hobby charger uses the ground wire from the pack your bms does not use the black balance wire but uses the main ground instead, that is why it only has 12 pins for 12s. Here is a diagram of how I connected five 2s Lipos in series to a 10s bms: It’s not the same setup your doing but the principle is the same.
As you can see, you don’t omit any of the red balance wires and you omit all of the black balance wires.
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Your bms is rated for 60a and can handle discharge as well as charge. You really should use it for both. Your Lipos will have more protection that way. if you do charge only, you will need to connect the pack ground wire to B- because the bms uses that as ground for the balance wires.
So instead of discarding the first pin of the lipo balance (the red wire), I shouldn’t connect the last pin (black) to the balance wires and use the red one.
Really think it ain’t necessary to use the BMS for discharge as the VESC is set to a safely cut off at low voltage.
@Namasaki Just to make sure, if I alter your scheme to this, it should work fine charging the lipo’s with the BMS and discharging them without.
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@oriol360 Bro! Thanks so much for this post 
You and @Namasaki have the most straight forward explanations for the BMS. Bookmarked 
I have never bypassed the BMS on discharge myself but I think it will work the way you have it. I was mainly showing how to connect the balance wires. Note: Some BMS’s have a ground port in the balance plug in which case you would use the the black balance wire from pack number one. Note: I’m not sure about port N- never seen that before. Just make sure that is for charge neg. if not, I think you’ll need to connect charge neg to B- Then again I’m not positive about bypassing. Frankly I don’t recommend bypassing but rather spend the money for a BMS that will handle discharge. You’ll be glad you did. My advice is, never skimp on batteries or electronics.
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The red wire is always the balance wire for the last cell in pack. The black wire is always ground, not a balance wire. Most BMS’s use main ground for balance. That’s why they don’t have the extra pin. Although the red and black wires are connected between packs in series, use the red wire for balance and omit the black wire for a more direct route to the cell being balanced. It’s better to discharge through the BMS because the Vesc only monitors total pack voltage so you could possibly have one cell drop bellow safe voltage before the Vesc would shut down. A BMS monitors the voltage of each cell or parallel cell group providing better over discharge protection. Not only that, it will also protect against over charging by regen braking. I’m not sure that’s the case when you bypass. Also the BMS will protect against shorts if use for discharge. I did actually short my battery once wile the BMS was on and it’s short protection tripped and shut the system down in an instant so nothing was damaged. Not the BMS, not the Vescs, not even the battery. This is why I say, don’t skimp, buy a quality BMS with high amp capability and wire it for charge/discharge. In the long run you’ll be glad you did. Or, you can buy a cheap BMS like this guy.
This is what I’ve been using since last summer and I have had no problems at all with them. http://bestechpower.com/37v10spcmbmspcbforli-ionli-polymerbatterypack/PCM-D223V1.html
how to order on bestechpower ?
Send an email to [email protected] Requesting to purchase the BMS by model number. They will complete the transaction by email. They accept Paypal and their minimum order requirement is 2. Total cost for 2 of the bms’s I use with shipping to USA was about $136 It’s really a good deal considering that they have a built in HV e-switch saving up to $60 on your build And they easily handle 80a continuous and up to 240a peak current discharge and 20a charge. Note: I’m pretty sure they ship to EU as well.
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@Namasaki
Thanks for the advice, only too late for me 
My BMS is already broken.
I have the BMS from battersupports.com (12S 60A) which is used a lot here with positive feedback. I already have a high voltage switch. If I new about this BMS with build in switch before, I would have definitely gone for that.
I use my BMS now with three 4S lipo’s. I wired my cables and connectors and tested the BMS with a volt meter. Black on B- and than I’ve tested the balance wires one by one.
At the sixt pin (in the middle of the connector for battery two) it didn’t measure any current. All further pins no current either. I’ve tested my wiring and those are good for 100% sure. Really think it came in broken, never even used it. I will open a dispute at AliExpress and I will ask them to send me a new one. Right now I will use my Turnigy balance charger (1S to 6S) to charge the battery’s balanced in parallel till I receive my new BMS.
The balance current on the Bestech is only 126ma I’d imaging that’s it’s similar on the battery supports. Possibly your meter isn’t set for that low of a reading. Therefore showing zero Also balancing happens at the end of charge cycle so there may be nothing wrong with your BMS
Note: I just checked and the Battery Supports BMS balances at 60ma
What was ur quoted price
$136.50 for 2 with shipping and PayPal fee.
Hmm alright thanks man!