Queen batt also has an aliexpress store so that’s probably one of the few im aware of that can he trusted.
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I need like 70 cells @Fosterqc , Fogstar won’t ship outside EU.
Local pricing are over 20usd/cell
@A13XR3 that’s good to know, thanks!
I’ll try them
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I love stickers so much, it makes everything look better
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You have some options. If you’re in the US, you can create an LLC (Limited Liability Company), which distances liability from suits and debt to the company and not you personally. Ease of creating such an entity depends on the state, and so that’s worth looking into if you want to sell things of questionable safety to other people.
Also, if you want to just build batteries for friends, then that’s a slightly different matter. That becomes one of those difficult questions to ask yourself, like loaning a friend money. How close are you? How much do you trust each other? Do they have family that wouldn’t be understanding if your battery pack failed and property was damaged or someone got hurt?
The actual liability and the result may be hard to anticipate, but the simple occurence of someone coming to you and blaming you for damage or injury and trying to seek compensation is itself a pretty crappy thing.
Selling t-shirts is one thing. If it breaks or the stitching sucks, you can just give them a new one. But if a pack fails, there’s a whole area of things to consider.
I started building batteries also, mainly for myself, but I’ll be selling some power banks to people I know personally. I’m staying way from selling internally used main batteries, just so I can trim away an area of concern with failure or risk. A low amperage power bank, even if all the fuses go or don’t work, probably wouldn’t lead to a crash.
A person I know asked me to build a Onewheel battery from Tesla cells he was trying to buy on eBay since they aren’t available through regular sellers. I declined, because I’m not taking on the risk of playing around with unkown cells.
Anyway, it’s all a lot to think about. Good luck.
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Ok sanity check please.
The plan is to build a 10S5P 30Q battery, can I do it like in the picture below or do you see any issues?
The pack is going in a 12S4P vanguard enclosure and does not need to flex
Now, is it better to do the series connection with copper braid or can I go with double stacked nickel?
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If you have enough width space, I’d go with two 14AWG wires instead
It’s a tight fit but might be doable. I could do it with the copper braid.
I like the idea of just having nickel strips to make the pack more compact, but not sure how well they will hold up to the vibrations.
So uh
Not sure how many people will care, but I finally sorted out my charging situation… Turns out I just needed a new bms. I either got a dud the first time or I broke it somehow between when I got it and soldered it…
I believe I read on another thread your B- pad (and maybe c-?) should be soldered first before inserting the balance cables. Not sure if its the case, but my shit is indeed charging now after soldering the c- and b- pads then inserting the balance cables
Thanks to everyone that helped me sort this out 
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A rule of thumb for the future:
First plug in your power connections, then plug in low-current circuit.
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Has anyone tried to spot weld copper (0.6mm) to copper with k-weld. Or is that a completely different beast.
Found something on youtube
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Do BMSes balance passively without the charger plugged in once the whole pack is full or do we leave it plugged in until the pack is fully balanced?
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depends on the BMS
so
what BMS
also
probably not
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yeah
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I’m so confused 
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if it could do that I’m sure they would have put it in the product description.
You should buy a smart BMS!
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Says nothing about it balancing when not being fully charged, in fact that first part seemly is saying at fully charged state it will enable the balance function. That is how those cheaper BMS work.
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I vote for copper of some type for the series connection. Either braid or single/doubled/tripled wires.