oh I feel like I made a thread or post where I wanted people to show what pins were shorted standard for all the Smart BMS variant. Wish they just used normal JST pins without skipping.
This info needs its own thread.
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Agreed (hopefully). But that’s quite a balancing act, keeping away from both the center and the ring. 
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I like that more and more people are using wire loom tape. I really think its superior in many many cases.
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It didn’t work, so I assume the voltage regulators don’t have enough juice to turn on at that voltage. I guess I just had to go plan B:
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Hihi so I’ve been trying to read all the advice possible before doing anything stupid and the prevailing trend has been “post pics in the builder club as you go”
Prep:
I have my P groups glued and fish paper-ed, and my nickel cut. I’ve also added solder blobs and half of them have the wires already soldered so I only need to make one join on the batteries after welding but it’s still easy to get the probes in. (The fish paper is adhesive backed but I used polyimide tape to double up on the adhesive, and I need to do 4 more strips of nickel)
Welding:
I’ve got a Sequre SQ-SW1 welder, a 5.5Ah “140C” 3S LiPo, and 0.2mm nickel. I’ll add pics of my practice welds on a dead cell in a bit, but I’m having trouble finding the right settings based off others’ reference images. I was always able to tear the nickel off with pliers and not a completely unreasonable amount of force, but it usually rips the nickel in the process so I assume that’s as good as it gets? My strongest welds were ~14ms on a full charge of the LiPo
Questions:
- Anything obvious I forgot?
- Are there go-to settings for the SW1?
- Any overall guides I should read? I’ve gone through a few builds here and this DRI/duck focused thread Esk8 Battery Building for Dummies
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That would be my concern. I cant say much on your welder but I do know that with a Maletrics and two 3s lipos in parallel, I was never able to properly weld .2mm. Even when cranking my settings upwards 60.
However, after switching to a truck battery, I was able to properly weld with .2mm. I can run my welder @ around 25-30 and welds are perfect. Just something to think about.
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I made this thread to try to assemble a few guides for Pgroup prep like that
Pgroup inc. Detail your recipe for those sweet Amps.
Been too lazy to write up mine, also My guide would not be the greatest.
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im using 2 3s graphenes in parallel and i get awesome welds on 0.2 with around 45 joules
never had any issues of weld strength
Thanks yeah that is helpful, I’ll look into car batteries near me. I had hoped because it’s advertised as a 2P with lower capacity and crazy C rating that it’d be ok, but it’s still running through one set of 12awg
Is that 25-30 ms or joules btw?
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Does this look reasonable?
I did some other tests to rip off the nickel and it pulled some chunks out of the nickel
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Only 12AWG? Seems pretty thin. I used to weld 13-17ms with 2 graphene lipos and even they got hot (I was able to get good welds with just 1 lipo on the same timings but the 10awg wires got really hot after a few welds)
Because the probes are much smaller than the kweld ones, your welds will tear earlier, but if the nickel is being left on the cell, those forces are way higher than the battery will see sitting in your board.
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10damons
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Yeah I went for the biggest thing I could find with reasonable shipping and got one of these lads, 12awg seemed small but I couldn’t find much bigger https://hobbyking.com/en_us/turnigy-rapid-5500mah-3s2p-140c-hardcase-lipo-battery-pack-w-xt60-connector-roar-approved.html
Ok great thanks that’s what I had thought and the logic makes sense so I think I’ll just work slowly and charge the battery often. Just take lots of coffee breaks
Are those series wires facing the wrong way? Or is it just me.
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Goddamnit someone realised before I could fix it 
Yes half of them are in the wrong direction, I was using a desk vice and listening to podcasts at the same time so I’ve got some re-soldering to do in the morning
It clicked for me when I was trying to line up the tabs for welding and couldn’t work out what was going on. Only welded the correct orientation ones
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So I’m having a bit of a weird issue with my new (5 cycles) NESE 12s7p p42a pack.
For some reason, group 3 sags about .15 volts below all of the rest when under heavy load. It also is typically about .04v below the rest of the groups. I watched it charge yesterday after turning the balancing off, and it charged a bit faster than the rest. The group eventually caught up and stayed with the rest of the pack for the rest of the charge which I found a bit odd. I opened up the module and everything looks good, nothing got hot enough to melt the petg and there are no weird marks so I think everything is making good contact. I checked the voltages of all 7 cells and they were the exact same.
So at this point, my options would be to clean the connections and just monitor them to see what it does, or just replace the 7 cells since it is so new.
Sounds like on of the cells has a higher IR than the rest. If you can, measure the IR of all cells in that group, If not, try swapping them one by one.
Wouldn’t capital M be mega seconds? I wouldn’t want my welder on that long 
Unless it’s just a joke that went way over my head
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So it looks like 5 of the cells have a resistance of 36 milliohms, but one has a resistance of 41 milliohms and the other has a resistance of 47 milliohms.
Would that signify that those cells are bad?
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