Help with new build electronics

Hello, I am a new builder and I have been researching and gathering information on what components I should get. After much investigation, I have determined, for the most part, what parts to get. These include: Motor Kit: Single drive motor kit with 83 mm wheels products/single-motor-mechanical-kit

Motor: Sk3 6374 192kv Brushless Outrunner- 80A

Battery: 2x 5s1p 8000mAh 30c Batteries ( in series. I already know that I need to buy a series adapter

VESC: products/torque-esc-vesc-bldc-electronic-speed-controller

Board: I’m using the board that I currently use to get around.

In spite of my many hours of searching, I have a few questions that I would love answered: ----I know that I need to get a BMS. The problem is that I don’t really know why you need one. I know you need it to balance charge your higher felled batteries but I don’t know what specs to look for. ----After getting the BMS, I need the charger. In one thread, someone mentioned a bulk charger but I am unsure of what that is exactly. ---- For the VESC, i know that the current max is around 50A, but I know that people use motors rated beyond that current. I am aware that there are two different curcuits at play and that the battery can be pulled at 50% voltage but still produce enough current for the motor. Regardless of this, will my motor be bottlenecked? ----Does a loop key basically count as a on/off switch so you don’t have to continually plug and unplug the batteries? ----Did I miss anything major or any other connectors that I may need?

Sorry for the long post, I just wanted it to be thorough so I can get some clear answers.

Thank you

Be sure to learn to solder and buy some xt90 connectors, bullets and an xt90 anti-spark, you’re going to need it

Also, a balance charger, or else you won’t be able to even charge your batteries, unless you’re going to use a bms which is going to be just a tad more complicated and also requires soldering.

A loopkey completes the circuit, you don’t unplug and plug in your batteries, and make sure its an anti-spark loopkey

(I really do not recommend getting a bms at this point, use a balance charger first and understand the basics of the electronics then move onto a bms)

I would say a BMS requires some skills and understanding to be wired properly. If you’re still not sure about all this, a balance charger is an easy option. That’s what I’m using right now.

Do you think going the bms route would be more advantageous for future projects and builds or would you just recommend sticking to the balance charger?

it will since you jsut have to plug in a power supply to your board and not remove the batterys every time you want to recharge

My biggest question a out bms’s is how to determine which currencts to pick for the continuous discharge. Also, someone mentiomed that if I get a bms, I need to get something called a bulk charger. I don’t really know what that is.

Depending on 2 things mainly… Are you going to use bms for both charge and discharge and how many amps will you draw from the whole pack ; ie what cells and how many in parallel?

If only for charging, a lower rated bms will be fine as long as you pay attention to it being matched up regarding number of batteries in series and type of cells.

If using for discharge as well it depends on your battery and how many amps you will draw. For example a 10s4p battery would usually require a bms rated at 60 or 80 amps.

I use 10s4p with 30q cells with a 60a bms for discharge.

The charger is usually a laptop style charger. Match according to batteries in series and type of cells and choose how fast you want to charge ; output charging amps.

You do know that diy skate sells 6374 motors right?518bed8205949e153446537f696eeac29c24887d_1_374x500

If you get their 218mm truck upgrade option, later on down the road u can upgrade to dual rear motors

@Holyman92 That is a good recommendation, to go for the 218 trucks to future proof it. Also, the reason I will go through hobby king for my motor is that it is ~$40 less expensive. @Sebike the batteries that I am planning on getting are 2 5s1p batteries. Does this mean it would be a 10s2p battery? Also, if I go for a bms for both charge and discharge, won’t it be significantly more expensive then a low rated bms for charging only?

Sk3, don’t have hall sensors and 30$ for a sensors motor really isn’t that bad

Because I know that’s you got the VESC from diy, any chance you know the answer to my VESC question regarding motor bottlenecking with the low max current in the vesc?

I don’t, I haven’t set my board up yet… I have to get the trucks, mounts and drive kits still

I’ve heard mention of that. What exactly is a sensored motor? And in another thread, someone mentioned that the vesc is able to make up for a sensor less motor

The vesc can but sensors help the vesc understand the orientation of the motors stator, helps to keep the motors in sync

So if I end up going to a dual mount at some point, it will be alot more beneficial to sensored motors? My only hang up I’d that the hobby king motor has about 1000 more power capability than the diy motor. @Holyman92

If wired in series 2x 5s1p will double cells in series ; 10s1p. If wired in parallel this will double cells in parallel ; 5s2p.

A higher amp rated bms will cost more than a lower rated bms if going with same quality range bms.

The charger you need could be cheap though. Without bms your cells won’t be balance charged unless you solve balance charging some other way.

Plenty to read on these topics in other threads…

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Ya definitely. The question that I keep trying to figure out though, that I can’t find on other threads, is whether or not the motor will be bottlenecked with the max 50A on the vesc, considering the motor is rated at 80A max.

Vesc rating is regarding drawn amps from battery. That’s more related to your battery output and not as much with the motor. Motor amps are what the vesc feeds it with, which can be limited in the vesc software.

@Sebike he could always do what I’m doing, get a BM12 cell logger (or any other cell logger) and a balance charger, u will have total control and monitoring of your cells at all times with the added feature of the cell logger alerting you if your cell gets too low or too far outta balance… with a BMS u have to trust that it’s working and hope it doesn’t break… If it does break u won’t know (usually) until u have caused permanent damage to ur cells

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