Hello! I’ve currently got 2 5S lipo batteries in series and I’m charging each one separately with an external charger. But I’m tired of disassembling my skateboard so I’ll be using a BMS. I checked out some tutorials on wiring but my BMS doesn’t have enough discharge current to handle my needs.
So I tried to bypass the BMS charging port and came up with this diagram. Can someone give me a clue as to whether this could work?
This is the link to the BMS I will be buying: Link to BMS
Well would you not rather loop Beyond the BMS?
also I after reviewing your ESC cannot confirm that it does in fact balance the cells (i.e monitor and charge/discharge outliers)
I think the key difference of bypass charging is quite simple rather than take from P- in your diagram you just Parallel from B- (if that’s understandable)
the physics of that situation make perfect sense only issue is you could unknowingly run your battery to dangerously low voltages so you need to install some sort of system to prevent that (some speed controllers have this cutoff functionality like “vesc’s” but also it’s wise to have in addition an alarm or other protection device onboard)
You need a diffrent BMS
and your wiring in this diagram is as such that when you are charging the board it will be powered on meaning you could take the remote and rev the wheels when it’s charging. (I’d say not ideal)
The VESC is pretty reliable, used by a lot of DIY ESK8 builds. I set the cutoff voltage as such that I don’t have to worry about over-discharging the batteries. You are right about the loop key issue, I moved it so I can pull it out while charging, disabling the ESC.
Thank you for reminding me that I need a different BMS, it seems I didn’t check the description well enough.
Do you think this one would be okay(the balance version, 3rd): Link to BMS2
Also, this is the new design.
Did you forget to type your reply?
Diagram looks nice now.
My last piece of advice Is maybe get an extender cable for the balance wires of the Lipos so in the future you could maybe disconnect them from bms and plug them into your hobby charger. (you can find these on hobby king)
and well the BMS seems to describe the desired functionality but I haven’t seen much of them in the wild.
This is deferential popular bypass balance option you may have seen.
No, he modified the loop key positioning for you
and spore the repetition of words I’ve already given you.
I bought the extender cable so I can combine 2 5pin connectors into one 10pin. Thank you for your help with this.
This is deferential popular bypass balance option you may have seen.
The one thing I don’t understand is this. What did you mean by this?
In other words: “Here is an alternative”
But my method would work just fine, right? Sorry for all the questions 
You method/Diagram is Good, You found a decent looking BMS.
So yes the design in theory/Math is Fine!
Hope the putting it together part goes well for you chao for now.
