Good point, I completely forgot to add battery pics, I have photos of the build process (which was done by @tinp123.
@That_Jamie_S_Guy I’m travelling with work for the next 24hrs so might be slow to reply but I’ll see if I have the photos on my phone!
Thx, I’ll wire some light on my next battery build. For the BMS switch, is that a rocker switch or a momentary switch…does it matter?
I thought I it would save space, but after looking at it again. I can arrange the mid group the same as the top group and and still keep the relatively triangle shape.
Not directly a battery question, or at least it isn’t yet, but does anyone have any tips on how to use a solder gun? My soldering iron is a bit under powered at only 60 40 watts and it can’t fully melt solder on 10 awg wire unless the wire is cut short, but my landlord has a 75 watt gun I can use. It’ll only be for those larger connections but I have no idea what the best practices are when using a gun.
I’m already using the largest made tip size that is available for my iron which is a 4.2mm wide flat tip. So the issue shouldn’t be the tip size but instead the output heat available. I do see that there are some cheap 80w and 100w units on Amazon but they all come with small tips which seem like they’d cause issues too.
Edit: Correction made to soldering iron wattage since apparently mine is only 40 watts oops.
I do 10awg with a 45w soldering iron just fine. Are you using a conical tip?
If it’s a temperature controlled iron, it might work if the heat is turned way up to like 420C+
If it’s not maybe let it sit 10 min to get really hot?
I can do 10awg with a 60w, but I can’t remember if I’ve tried on a 40w.
There is a great thread on soldering that might have some tips too
I’m using a 4.2 mm flat / screwdriver tip. Largest conical tip I have is 0.2mm and I don’t remember seeing any larger conical tips available for my iron.
It looks to be getting up to around 360 c but that is being measured with a temp gun and might be off since the metal tip is slightly reflective.
I know how to solder with an iron but I just usually solder very small parts for the most part. 1 mm wide small for some stuff. My issue is that I was going to run 10 awg wire through my deck for the battery connection which will act like a giant heat sink.
I don’t know the best way to use the solder gun though since they’re horrible for precision so I never bothered with them before
Hoping someone can help me diagnose an issue.
The other day my VESC (ubox v1) turned off while I was throttling up a hill. I’m pretty banged up but mostly ok. First inclination was a bad connection on the battery, but everything looks good here, right?
What else can cause a VESC to just turn off? Any ideas/tips are appreciated, I’m not the most familar with the ins and outs of batteries
Does the VESC work now? Was it a fault or a full power off and you were able to power it back on?
The series connections look good, but maybe check the welds and the voltage at the end of the pack while moving the battery around to see if it fluctuates
Do you run the discharge through the BMS?
Yeah, the VESC seems to work just fine and powered right up afterwards…I believe discharge is run through the BMS but tbh I don’t really know what I’m doing. Which connection would that be? My previous build bypassed discharge and I never had an issue like this. Pic below
I caved in and bought a ts100 iron after realizing that it took 20+ minutes just to remove the remnants of solder and 10 awg wire from my VESC. Now if only I did that last night after it took too many hours to remove the other 5.
I’m blaming you all for making me spend $90 on one tiny soldering iron and a replacement tip though. 
This might be the cause. Running fast up a hill uses a lot of battery amps, and may have triggered the BMS’s overcurrent protection cutting off power to the VESC.
There are a few threads on how to wire it up as bypassed
Sorry, better image here:
Can I just sever this connection and tape it off?
Edit: after looking at the diagram again I think I understand, going to have to resolder a bit
That second B- does not look well soldered.
There should be 3 connections to a BMS. B-, C- and P-
B- goes to the battery negative.
C- goes to the charge port negative
P- goes to the ESC negative.
P- is what you want to change. Disconnect it and connect the battery to the ESC directly.
No it can’t just be cut. It has to be changed.
Change from drawing “A” to drawing “B”. Note that the drawing shows a BMS where P- and C- are the same port.
Jeeeesus that’s some average soldering. I hope that’s not mine 
No, you have to disconnect your ESC from the C- port (On the right side on this photo) and connect it to the B- port (the one you have the arrow pointed to).
You want a straight path from the battery negative to the ESC with no BMS in between.
The only thing that should go to your C- port is your charge port, and any accessories (lights, USB ports, horn, heated seats).
Not always. His BMS looks like a combined-type BMS, with only B- and C- (C- and P- effectively combined). He needs to move his ESC from C- to B-.
Thank you for the concise explanation, was wondering why I didn’t see a P connection
You’re welcome! The different varieties of BMS connections (and labeling schemes) can be confusing at times.
(Edit - Whoops, sorry ApproachCautiously, meant that reply to go to havenever instead!)
It looks like I have 2 separate negative connections going into the B- ports from the battery negative… does it matter which one I disconnect? One is enough right?
