Hey everyone, so I’m a newby in the DIY e-board space. I’ve pressed my own decks in the past, but this is my first electric conversion! I’ve been doing some research/planning and had some questions for you all regarding the design of some electrical subsystems.
Battery pack: I’m planning to make my own 12s10p pack using 21700-40T cells. I’m doing this partially to challenge myself to build a heftier slightly more unique pack than most DIY builds do using 18650’s, and partially cause it seems like it’ll be pretty bad ass (torque and range wise). My questions is, am I out of my league building this thing as a first timer?
BMS & ESC: from everything I’ve read the best way to configure a BMS into your build is to only use it for telemetry (cell voltage, temperature) of the pack, and for controlled charging and balancing. It seems like the consensus is to use your ESC to govern discharging. Assuming what I’ve said is all correct, how does the ESC/BMS do this? WIth a 12s10p pack driving four motors with connected ESC’s there would be a total max continuous current of 350A / 4 motors resulting in ~87.5A max CC per ESC (if my math is good). Is there an intake current rating for ESC’s?
What are the primary characteristics that drive ESC and BMS selection. From what I’ve seen ESC spec’ing is primarily a function of output current (i.e. to the motor), and BMS spec’ing is primarily a function of charging current. Does this mean the intake current for both from the battery does not matter?
Do you all have any recommendations for BMS’s and sensored ESC’s (VESC’s specifically) capable of handling the high current output from 12s10p pack?
before jason jumps in here and tries to sell you my buddy’s unity I think you would be well off with the standard or upcoming budget TRAMPA VESC or cheaper being Torqueboards TB6, Stormcore 60D.
I think for something that big a heavy AWD would be nice then you only really need something that can do ~50A const.
@Fosterqc thanks a bunch for the info! Certainly helpful. I’m aware of the TRAMPA VESC and the Stormcore60D, though I didn’t know there was an upcoming “budget” TRAMPA ESC. Is the one you’re referring to the base model (60V/100A CC)?
As for the Torqueboards TB6 - I see they’re coming out with a new ESC soon: is this the one you are referring to? Or was it one of these two?
Also, I definitely agree that doing AWD makes sense with this big of a battery pack. I get the 50A ESC rating is with reference to the output to the motors, but do you happen to know if there is an intake current rating (i.e. from battery/BMS to ESC) on these controllers? I just want to make sure I understand if there are any constraints on the ESC from the perspective of oversupplying current. Thanks!
@Fosterqc Oh, I see okay. So in this case if the 50A is an input current rating if I had AWD (max 87.5A ) wouldn’t this surpass the capabilities of ESC’s with a 50A rating?
idk what motors you had in mind but 6355 are totally good for awd.
I think you should get 4 motors and 4 TB6 (not released at this moment sign up for the email on torqueboards.com)
That would be a killer setup.
About your BMS questions, just order a 12S smart BMS from esk8life and run it bypassed. Show us your wiring plans before you start cutting wires and melting things.
For simplicity for my first build I decided to go dual drive instead of AWD
These are some of the components I’ll be using:
Battery: 21700-40T 12s5p
BMS: wired for 40A charge and 130A discharge
ESC: dual Trampa VESC MK6 IV
Motors: dual Maytech 6365 170kV (65A)
Drivetrain: belt drive (12T motor / 72T wheel pulley)
Wheels: 8” pneumatic
Charger: 4A
Remote: Flipsky VX1 for VESC 6
Lighting: headlight and taillight wired into via buck converter (36W/light)
