This is not your typical buy new parts and make a shiny spaceship build thread. This is the trash that begs to be trashed again build thread. I call this board “Schrödinger’s Phoenix”. The goal is to learn how to build something that actually moves me and not to worry about it breaking. I hope this may inspire others that it is possible to build a deck on a budget and to just try small, fail small.
That being said, here’s what’s going into it (see image, there is really not much to say about it).
Final cost breakdown (neglecting shipping costs and tools- real cost is 50-100% more)
beaten up used Chinese kit - trucks, mounts, motors, pulleys, ESC, remote and some crappy new wheels ($50 local pickup)
used Evolve enclosure ($25 forum, with other stuff)
35A 10S BMS (discharge bypassed) ($20 Amazon)
Deck ($30 local pickup with other stuff)
20 Samsung 25R ($40 forum, bought in lot)
X-brackets ($4 dickyho)
connectors, cables, nickel, shrink wrap, solder, hot glue, jbweld, thermal glue, screws, double sided tape, neoprene gasket, riser pads, and wrong parts are not accounted for
That looks like a bentley compared to my first build. Dc motor, rc car speed controller, and remote was the size of house brick. Tons of epoxy and lunchbox
Be carful with 18650 holders they are only rated at a few amps not the 45amp you pack will put out. Reinforced the the terminals with copper wire, rod or thick 10mm desoldering wick. If you dont plastic will melt.
Thanks for the warning about the cell holders. These are made with some really solid leads though. The ESC will limit the current anyways to either 18A ~ 30A. It’s also a temporary solution until I can borrow a spot welder.
Here’s some progress:
Decided to ditch the enclosure and just build my own so I could arrange the cell holders nicer.
Soldered most connections for a 10s3p pack.
I agree, NESE is the way to go. But I got these holders already (for making 12v packs for lights, no longer needed). So I might as well use them. Also, I will be using cells that cost me just short of $2/piece (thanks @BigZwatt) - NESE premade costs even more than the cells. Even if I could 3D print it for free, the hardware would still be more than $1/cell pre-shipping.
But in the future, for nice packs with nice batteries, I am looking forward to use NESE
It definitely is the weak point. The tabs are really thick though - about double or triple that of nickel strip. Think of it as cell level fusing .
Joke aside, I would not do it like this again.
However, I feel confident enough that it will support 5-10A.
One issue I am facing: I did not get those nice round discs for the outer side of bolts connecting wheel to pulley. The screws are too long like this. Either I just cut them shorter and call it a day or I buy some or CNC some. Do people have issues without the round outer discs?
The first time i used 18650 i used same holders during a long ride i lost power and one of the battery clips had melted the plastic and poped out. I had done over 100km already so may have been a faulty cell. I had copper braid running throught the battery clips and soldered. The soldering also weaked the plastic. After that faulure I boulht a chinese spot welder big mistake, but I wont go into it now.
10S3P 60AMP constant capable - battery 20R I think it was years ago. Max at vesc was 40. Its rebuilt with spotwelds in a 32" traditional skateboard. Single motor.
Got to borrow a cheap spotwelder and decided to scratch the cellholder approach. Boy, the spotwelder is hard to use, had a lot to learn, and still do. I see this as an exercise, rather than a masterpiece.
I appreciate feedback on how I can improve my battery build for the next time!
So, here are the spotwelded cells (10s2p) (I added some fishpaper later under the positive terminals where I forgot to add it):
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