Hello to all professional and experienced battery builders,
I was reading for several hours the thread in order to build my own (I guess spot welded) battery pack. But honestly there are so many options and techniques that I wanted to ask what is the:
Best and most reliable DIY spot-welded battery pack system I could go for? My target speed is something around 38km/h (24mph) and distance around 45km (min. 25km).
And which battery management system would you recommend me?
Thanks guys
The top speed depends on your gearing, wheel size and motor kV.
You find a calculator for that on the top of the forum side.
You can reach your desired speed with a 10s or 12s battery, that’s totally up to you.
To get you some p group count we need to know if your board is an urethane wheel street board or an all terrain/mtb with pneumatics.
Thank you for your super quick answer Andy.
Okay so it will be a 10s or 12s then.
I was thinking about the 85mm orangatang wheels. (I also really like all terrain wheels, but seem to be hard to get, more expensive etc.)
Thank you for the calculator information.
If you go urethane than you can calculate about 16Wh per km (this number can vary depending on how aggressive you ride, how heavy you are etc.)
So if you want a range of 45km, your pack need to be 16Wh x 45 = 720Wh
A 10s7p pack of 30q cells would be
10x3.6Vx3Ah x 7 = 756Wh
Keep in mind that one 18650 cell is around 50g so that pack would be around 3.5kg.
What is the most common set up here? 10s4p? Or what would be the overall best solution, for weight-distance-carriability? Maybe a 10s4p?
And could you recommend me a spot welder that is of good quality and reliable for years to come?
20-30Wh/km. Depends on the terrain and which pressure you pump up your wheels to.
malectrics or even better kweld.
I would have never expected them to be more. I thought Urethane needed more energy… Great news 
@moon Thanks I will have a look at them both. Hopefully they are in my pricerange. Which page would be best to order them ?
Its a lot easier and usually cheaper just to pay someone to make you a battery, trust me.
It looks interesting and fun to make one on your own but its not that easy, especially the first one, it wont go perfect and the way you image it for sure and you will probably have doubts that it will fall apart sometime in the future and set itself on fire.
If you pay someone experienced you will feel a lot safer with the pack for sure
At least that was my case with my first battery 
Yeah unless you plan on making multiple batterys you’re better off paying someone that already has the equipment and experience
I disagree. I built my first battery and it was cheaper to buy a spot welder($150) and all the materials to make the battery. It was a 12s5p so maybe if it was a smaller pack I would agree.
Both my batterys I only paid 100-150 for labor…
If you count in the time you did learning reading etc it came out to probably a 1000$
You don’t calculate the time you research and learn something for yourself in your free time.
If I would I could probably buy already 25 trampa prebuilts for this money
This is just wrong lmao. I am assuming you are a battery builder from your comments here and since you said you ordered from nkon every month for 3 years. So what would you charge for a 30q 12s5p flex pack with a charge only bms?
From who? If that’s the case I would have maybe bought it. So a 12s5p for $400? I would gladly pay that. I have seen 12s4p for close to $600 when I was looking and that’s what I based my decision on. Im glad I did though since I have built 3 packs so far.
Psychotiller and hyperion lol
*I might have gotten a good deal 
I’ve got a spot welder now.
Just gotta convince the wife I can do it safely in the apartment… not going well.