Depending on where you’re located, I’ve found several sources of 25mm and 30mm strip.
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So i “made” a welder out of a welder. It does great welds but is kinda low duty cycle equipment. I get about 18-20 sets of three welds done before i have to wait and let it cool off. What are y’all using and does it perform better?
This is what ive got ($20 i think ages ago) and i had to fix it before the first weld to make it not self destruct. I was thinking about upgrading to a welding pen but I don’t know how well the rest of it would fair if I didn’t stop as often, fets would probably take a shit if I could go to town with it. I can probably increase the duty cycle with a pen AND heat-sinking the fets better, but I don’t want to spend the same as a better welder upgrading this one.
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Yes you can, make sure to sand the nickel leftovers off the can. This is the positive terminal, it has a “lid” over the actual cell contact.
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I was thinking of pulling the bottom tab off instead of the positive
That is a slightly more risky proposition, if you disturb the bottom there’s a chance of rupturing the cell can and ruining it. Also as Mooch mentioned below, tugging on the bottom has a chance to potentially cause a short or open circuit.
It can and has been done, but I’d personally rather not fuck with it.
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The bottom (negative) is harder to take off without damage. Id recommended hitting the welds with a dremel to thin them up a bit and make them break off without damaging the cell. The positive side is more durable and you can probably rip it off carefully (dont let sharp edges short the cell) without any prep with .2mm. .3 or more and it starts getting harder.
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The seal is at the top and wouldn’t be affected by a damaged bottom but the bottom is directly connected to the (spot-welded) negative tab to the spiral roll inside the can and is very close the active parts of the cell. Damage to the bottom could potentially damage that spot-weld and/or cause an internal short circuit.
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I was more referring to a potential leak if the steel can is ruptured, but I worded it badly.
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Personally, I find it much harder to get nice joints w the nickel floating like that. The less-than-stable nature of the surface makes it tough. Why are u soldering like that?
soldering was done flat before I welded it ontop of the cells, less heat dumped into the cells
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That’s because it depends entirely upon the polarity of the thing plugged into it.
First idea would be to look at the datasheet if it came from a place reputable enough to have one. Second option, I recommend plugging in your charger (or a spare 5.5mm jack) and using a multimeter to check continuity.
The third connection is switched - it will connect to one of the others, but only when a jack is plugged in (Or only when one is not plugged in, one or the other).
(Generally speaking the centermost electrode (the far right lug in your photo) is positive, but don’t trust anything. Check it yourself, ten seconds with a meter might save you a blown BMS or charger.
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Idk why i didnt make sure it was a 2pin charge port when i bought it…
After posting i found this and wired the positive to the one you described, and the negative to the one directly opposite to it.
checking continuity generally confuses me, will it work if the raw charge port is plugged/soldered into nothing? I just finished the build now, pretty tired but will probably reply back with pics to make sure I did it all right before i plug any charger in.
this is the charger i’ll be using for it since it has the same charging connector
Meh… I think the heat transfer is negligible. Just in case though, I fashioned a 3mm thick copper heat sink attached to some fish that I shove under the nickel when soldering. Makes ur life so much easier.
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Is this how most people wire 4wd packs? or is it better the have the battery connections to one esc be short and the other long
Im no expert: but that looks like a dead short battery or an open circuit? Or is it two separate batteries?
On my 4wd hub board I wired a splitter from the single battery output to feed both esc… but hubs are much lower draw than most outboard setups so let someone with more experience guide ya.
Where is the short? i think my drawing is just bad, which is probably confusing. its supposed to represent basiclly 6 p groups (because im too lazy to draw 12)
E: to clarify, green wires are series connections and the orage are the leads going to the vescs
Kind of just wondering if there’s cause for concern here.
12s pack won’t charge to 50.4v and stops at 50v.
End of charge (charging off)
End of Charge (trickle)
Beginning of charge (unused cells)
All cells are unused, just welded and strung them up last night.
What is your charger putting out?