JoeyZ5's Battery Building Adventure

[JoeyZ5]

November 11th marks my one year into ESK8, so I figured maybe its time to get into some custom batteries. I have used NESE for my eMTB build (which turned out great, if you are interested, check them out here) and lipos on my cheap urethane build.

I have yet to use a custom welded pack, so I figured why not learn to build them. I knew from past experience in this hobby, buy cheap or buy twice (or many more than twice) so I decided to just go all in and get a KWeld.

It came super fast and looks great, nice work @tatus1969. I wanted to make sure I was getting the best performance possible so the whole time while assembling I was cleaning all contacting surfaces with isopropyl alcohol incase of any dirt or residue that might increase the resistance.

Soldering the XT150 connectors to the 8 AWG cable wasn’t too hard with my 60W iron. Though it might be helpful to get a more powerful one in the future.

I tested it by powering it on with my smartcharger at 12v. Resistance was 2.32 mO, under the manuals 2.5-3.0 mO typical resistance.

Next was to make a case, which I printed in PETG with red PLA letters glued on. Turned out very nice.

Here is the KWeld letters I cut out from the original case file.

KWELD Logo.stl (132.5 KB)

For the battery, I chose a Turnigy Graphene Panther 6000mAh 3S 75C Battery Pack

Stuck to the side is a 3s charge only 3a BMS for easy charging with either a regular 3s 1A wall adapter or 3A through my smartcharger. In calibration on a full charge, I got 1774A. Literally perfect for my cable cable length of 1.2m which has a max safe current of 1800A.

For nickel, I went with a kilo of some 30 x 0.2 mm strip from Aliexpress.

Took around 25 days to arrive and did not rust after it was scratched up and put in salt water for 48 hours. Came in a coffee scale box? Confusing but works well to protect the nickel.

Now lets get to some welding!

I started on a knife blade at 10 J and increased by 5 J on every consecutive weld. I ended up going to 45 J after I took the first picture.

40 J looks nice here but on an actual cell 30-35 J seems more reasonable.

This ends the setup of my welding gear. I will continue to update this thread with work I have done. Hopefully in the future I can make a few packs for some of you here and there. I honestly love tinkering with this kind of stuff. When I’m working on my Esk8 stuff I just put on some Spotify and jam while getting the feeling of building legos again like I’m a little kid again.

[magharees]

nice choice of components, case, write-up & assembly, enjoy!

[Agniusm]

Counter intuitive having no solder/weld modules but i got it as well for odd job

[JoeyZ5]

So my first official welded pack is not going to be an ESK8 pack sadly, it will be a hoverboard pack. I got a hoverboard on facebook marketplace for $40 and I plan on restoring it (As a little gift). One of the main things to do is build a new battery. The old battery was made horribly. 8 x 0.1mm nickel and no P group insulation.

I dismantled the pack and am recycling the cells, I plan to reuse the BMS as it doesn’t look too bad and it makes fitting the same form factor easy.

I cut all the nickel shown from my roll of 30 x 0.2 mm, turned out nice and should fit with all the BMS tabs right if my measurements are right.

[tatus1969]

@JoeyZ5

40 J looks nice here but on an actual cell 30-35 J seems more reasonable.

Awesome build log
Your blade tests look strange to me, as I would expect a stronger gradient. Maybe you can make a test weld with 0.1J, this should result in a near zero pulse duration and little effect on the nickle strip. If you don’t get that then your calibration is probably off, in that case check/faster all screws (also the electrode set screws, but be careful there as they thread into copper), clean the tips, and make sure to press the tips together hard during the SHORT test. Make sure that you don’t get any sparks, otherwise repeat.

[JoeyZ5]

I redid calibration, no sparks, and just to make sure I checked all fasteners and probes. Here’s the results

Here is the test on knife blade at 0.1 J

Nothing really happened. I’m hoping that’s good?

[magharees]

@JoeyZ5

0.1 J

Not enough joules to knock the froth off your frappuccino

[JoeyZ5]

Finished my first pack! Went petty smoothly.

Here’s the build:

I used the black HMA that ZachTetra uses and it turned out pretty well. By the end I was getting nice smooth lines of glue between the cells. Either way it was getting covered with fish paper.

Also I have a question, how do you all get the fish paper perfectly aligned? On many I had to trim off some excess as it was at the slightest angle at the end of the wrap.

Welding begins:

First weld of my first real pack! Real history for me right here

I think I got the hang of this pretty quick.

Here is all the P groups for the hoverboard pack:

The fishpaper added some extra thickness to the width which made assembling the cells to the BMS PCB a little tough.

The build was pretty easy. It took a few hours but I was going at a snails pace to make sure everything was perfect.

Here is the finished results:

(My shrink wrap calculations were a little too big but its mostly tight.)

(I know the name isn’t very creative I’ll think off something soon)

[JoeyZ5]

Just some pics I took while building a 10s3p brick for a portable board charger.

I’ll add more once I finish.

[JoeyZ5]

Moving my 12s8p P42A progress over here.

Here’s the previous pictures I posted:

The battery builders club

Rushed through my physics homework and got a little bit started [image] [image] [image] [image]

And here is the progress I made on day two.

Welding is 75% done, I need to cut/weld balance tabs and then mount the two last p groups on the top perpendicular to the rest of the pack.

[ARZ]

Looking fantastic! Hopefully it all goes well

[JoeyZ5]

Here’s the last bit of the build:

Went pretty smooth, just waiting on XT150s for the main connections.

The welded 12s8p P42A is actually smaller than my old NESE 12s8p 18650.

[Fosterqc]

This is one attractive battery.

Sent that shit to Elon ASAP you’re hired.

[JoeyZ5]

@Fosterqc

Sent that shit to Elon ASAP you’re hired.

My mom keeps telling me that I need to show this stuff to colleges when I start applying

[ZachTetra]

Seriously dude it’s worth it, saying you make high power li-ion batteries with smart sensors for personal electric vehicles looks spectacular

[JoeyZ5]

Hey guys, I just recently finished my 8th (I think) battery build and now I’m out of them to build! If anyone wants me to build them one for them, I would be estatic to do so for a low cost.

I’m a high school student (don’t let this discourage you) so right now I’m doing a lot sitting around at home with school being mostly online. I’m not trying to do this make a ton of money, but its something I love to do (It brings me back to building Legos like when I was a kid) and a little bit of extra cash here and there wouldn’t hurt to fund my esk8 expenses. (belts and tires start to add up quick ) There’s just something about putting on some Spotify and building a pack that is just so satisfying.

Quality and safety are my #1 priority, and I’m willing to put in as much time and work as possible to make my batteries the best. When I’m bored on a car ride or even on the ski lift, I’m usually reading the battery builders club thread. I’ve picked up many tips and techniques along the way and so far I’ve gotten several compliments on my work. The builds will be posted here too so kind I know there are many eyes on me.

For my first few builds, I plan to start with costs low to encourage sales, as right now my priority is to build my portfolio and gain more experience. Maybe somewhere around a $50 start cost and $2-3 a cell plus BMS and any extra costs, but this is subject to change. I feel like this is a very reasonable and affordable starting point.

For warranty, there is not much I can offer but I will fix the battery if it is DOA for free as long as the buyer pays shipping back to me. For a limited time I can also try my best to make things right within 35 days of you receiving the battery. If the battery is tampered with or mistreated in any way or used outside its ratings, the warranty is voided.

Feel free to send me a PM if you have any questions or are interested in a battery.

Thanks for all the compliments and advice so far!

Edit: Forgot to mention this is only within the CONUS and through PayPal.

[frame]

@JoeyZ5

only within the CONUS

sad noise

[Movation]

You do super tidy work, I am impressed…

[JoeyZ5]

Cute little 4s4p pack for my friends dad. It’s going to power a fishfinder, designed to last around 10 hours.

Hopefully the 30mm wide nickel will be able to handle the 1A max load

Just waiting on the BMS from bezos now

[Fosterqc]

So cute