any cheap 18650 battery welders?

chillinn

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Here's a recent thread about custom battery packs. DIWdiver knows, can do, and if he sees this thread, he will probably unintentionally talk you out of whatever you have in mind. I am by no means volunteering him, I'm just a fan of his posts. Maybe what you have in mind is simpler than what Rommul was interested in, and thus will be easier and less expensive.

Maybe... you know... describe what it is you have in mind before someone comes along and asks, save a little time. Do you want them welded to the hood of your car? Perhaps welded to your kitchen sink faucet? Maybe you want to weld 18650s to all your door knobs? Just kidding, likely you want some sort of custom battery pack. But there's really way to know for certain unless you share what's going on in that attractive mind of yours.
 

DIWdiver

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Thanks for the kudos, chillinn.

I know you are just having some fun, but undoubtedly the OP just wants a battery tab welder, as anyone who makes battery packs should have.

In the thread you linked, the welding of the batteries was a lesser part of the project. The biggest part of it, at least for me, would be the construction of the physical structure of the pack, which has some pretty unusual requirements. Here it sounds like the tab welding is pretty much the entire project.

The cheapest complete tab welding system I have seen is around 140 USD, and it is REALLY cheap. It's available on USAbanggood, and probably under other names at other vendors. Proper professional ones start at ten times that and go up from there, and that's just the basic unit, without leads, hardware, etc. I expect the chinesium ones would work reasonably well until they don't work at all. I don't know that I'd want to invest that much money in something so questionable. But I'm a cheap ba****d.

I've seen a number of DIY jobs that range from far more cringe-worthy than the $140 chinesium ones to reasonably respectable performance. Some of the reasonable ones look like they cost less than $30-40, but they take a little bit of skill both to build and to operate, and more than a little time to build.

Recently I realized there are a bunch of units on flea bay that are semi-DIY. These are intended to attach to a (VERY) high current (but remarkably small) LiPo cell, or a large and somewhat expensive capacitor bank, or even a good sized lead-acid battery, and otherwise are pretty much complete. They are FET based controllers and are remarkably inexpensive, ranging from $25-40. Theoretically, they should give pretty good results with a little practice. Clearly they are not made for volume production, but for a few packs here and there, they might be perfectly adequate.

Unfortunately, the bulk of the cost is in the power reservoir. The two 3000F supercapacitors recommended by one unit range from $33-95 each in my quick search, depending on what you get and where you get it. You'd need to add a 5V power supply on top of that, but that should be no more than a few bucks. I didn't explore what a 300-500A rated LiPo would cost, or a charger. A lead-acid battery suitable for some can be had for $45, possibly less. Think tractor or motorcycle battery.

A good way to learn about these things is to google 'battery tab welder', go to 'images' and start clicking and reading (or watching).
 

raggie33

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ty everyone for ya input . i think im not going to pursue this project
 

Lynx_Arc

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Same thing happened to me. I was considering a battery welder setup but found it way too expensive for limited hobby use the research was a bit too daunting and safety concerns too risky. I also considered soldering the batteries myself but that was also a bit too risky even though I am very experienced at soldering I don't have a regulated soldering iron which I think is necessary to even consider that option altogether.
My concern was damaging the cells or having a cold solder joint and the wire slipping off and shorting things out somehow. I purchased some cheap 18650 battery holders but have not used them yet. I don't recommend these holders for more than an amp though either the springs are too small or the contact variety is made out of easily meltable plastic that I think could deform under heat and cause issues perhaps.
 

raggie33

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i have the spring 18650 holders they could not due high amps the other ones i bought was better they have no spring but i forgot there name but they could handle around 15 amps
 

Lynx_Arc

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i have the spring 18650 holders they could not due high amps the other ones i bought was better they have no spring but i forgot there name but they could handle around 15 amps
I've not seen ones that I think could handle 15 amps. The contacts of the ones I have may handle that much but the cheap plastic they use could easily heat up and deform or melt and cause shorts or some other hazard. I don't think you can count on cheap battery holders safely doing more than about 5 amps from lithium ion responsibly over any length of time. For most of my projects however 5 amps it plenty enough. My problem is I've been trying to mod work lights to 18650 use like 3AAA and 3AA lights and can't fit an 18650 with a holder in the light and without a tab welder I can't use it without a holder. I do have micro USB charging circuits that if I find room I can make integrated charging work so I don't have to worry about either removing the battery or try a magnet based charger.
 

Sharkydog

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Oct 2, 2020
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18650 batteries

Hi all this may be the wrong part of the forum to post in ?
I have just bought an imax b6 charger and an xtar vc2 charge packs and now
looking to start replacing faulty cells or building battery packs using 18650 batteries.
i am looking for recommendations for cheap battery spot welders .
also where is best to buy welding strips lugs holders etc .

TIA Scott
 

etc

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Re: 18650 batteries

if it takes a single 18650, does not have to be protected. Only multiple cells in a device need to be protected.

the latest greatest is 3500 mAh, not sure if that has been superseded yet.
 
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