IFR 26650 Powerbank

Thanks for the inputguys :D

So i triedthe 300W unit 5 sec on-of and 5 sec on again and after another 5 sec the solder starts to flow.. but the cell is super hot.. I tried to measure it with my infrared temperature unit but it's not working well on metal surfaces



The iron is about 300 celsius depending on the "black" spot i measure .



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no way to touch the cell..
the cell's maximum operation temperature is 55 celsius according to the spec sheet.. :p
But I don't believe the measurement.. :s the infrared doesn't works on shiny metal surface so it might be much higher...


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When I tryto solder the negative side the small seal melted and the life liquid comes out .. No good...


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messy ugly soldering with the 300W thing

So I have 9 packs 8x8 cellsready but no stable way toconnect them for now :dodgy:



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Sounds like they wont work with soldering. Sounds like the heat is transferred faster than you can add it. If so, spot welding is the way to go or holders with springs or such. Note that you need beefier spot welder than the normal ones out there as well. (Or atleast might need) Depending on thickness of the cells casing.
 
Slap a piece of masking tape on the cell to get a better reading. Also, put the gun much closer to the cell so there is less for the sensor to average our. I put my gun directly on the cell and move it slightly both directions to get the highest reading.
 
if you only got the cell to 55c in one spot from soldering, i doubt you hurt it. Now if insides are oozing out, thats a dif story.

use a solder that has a lower melting point.
 
The iron is about 300 celsius depending on the "black" spot i measure .

Ok 340-370c would be better iron temp

And make sure your using low temp solder.
Sn63Pb37
Sn60Pb40
 
Thanks for all the help guys.
So I tried some more soldering ... I'm not happy with the result and (over)heating of the cells.
The 300W iron is crazy but these 26650 cells don't like to be soldered.
After watching Daniels movie:
I figured that spot welding for the fuse wire and negative side is the way to go. The 300W iron wil be great for soldering the buss bars.

So I'm waiting for the spot-welder to arrive and I'm figuring out the buss bar design for a 36 8x8 pack.

Next thing will be a BMS that can charge and discharge at the same time for the RV powerpack.
I will make a packs 4Sx 36P cells to create a 12V pack of 100+ A
This packs is for RV lights waterpump and operating the heating system.
I have small 30Wp roof mounted PV with build in charge controller giving 13,8V to charge.
When the engine is running I want to have the "12V" (14,5V) 120A alternator to charge the pack.

Any tips on a existing BMS that can charge and discharge at the same time with a 13.8 V input?
 
It's possible you may need to do a slight abrasion where you want to solder to. Take a dremel tool with the drum stone and lightly rough up the spot you want to solder. Then see if you can solder to it. You could also just use a piece of high-grit sandpaper, but the dremel is more accurate to get to a small spot. You don't want to over do it other wise you will expose the underlying metal and it could rust. (I found this out on a few cells I had left alone after using the dremel on them and hadn't gotten them soldered. A couple days later, there were rust spots starting to show)
 
I tried wire brushing and grinding. it helps a bit but still overheating and bad flowing of the solder.
 
Hmm, maybe it's too hot and that keeps it from sticking?? What solder/flux are you using?
 
They should all be made from steel with nickel coating (hince being careful not to over scratch them). They aren't SS, as that's a poor conductor. Not sure what to tell ya. Could you possibly make a video recording of ya trying to solder to them so we can see what's going on?
 
Cheers guys, Just came back from a short holiday in Sweden. (Sorry Daniel, next time I will drop by ;) )


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To find some new toys at m6 parents:D


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Spot welder will be tested next week.

And another 20 meters of heat shrink....


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whoopee cutting time (#feellikeamachine)..
Around75mm a pieceso 266 cels to get a new orange coat :D

I can try to make a solder video next week when I have some more time.
 
Dind't make time to film any soldering sorry..

Instead I tried my new spot welder. aka fuse blower :dodgy: ...


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When the fuse is not blowing it works great :p..

unfortunately my automatic fuses popones every 2 welds..
When I'm luck it's the automatic fuse next to thewelder..
When Unlucky I have to go tothe main fusebox to switch them back in place..

I made my first busbar design 3wire's twisted and soldered with the "BigGun"(Chinese300W iron )


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The wire's are going through the pack to prevent any stress on the busbar during transport/ installation.
The wire's are recycled from the "old packs".


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And after a lot of fuse frustration one side is finished the "BigGun" isnice for the busbar soldering :)


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Note: This is the Negative side! So these ar not Fuse wire's!

I recyclethe heat-absorption padsfor isolation and protection that come from the "oldpacks".
It's some weard gummy stuff with a pink plastic film on the topside. Really funny when you place it on your hand it feels "cold" so I guess it works :D.


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Now I have to find a way to use the spot welder..
Find a place with "industrial power" or change the fuse's at my parents place to "slow old schoolglas fuses"
 
Ok, so are they fuses that are popping, or breakers that are tripping? A lil confused on that one

* If fuses, then you probably should run a dedicated line from the fuse panel for your welder.
* If breakers, either run a separate line as above, or, depending on the age of the breakers, it's possible the breakers are weak and tripping prematurely.

In both cases you are going to take your wire size and breaker/fuses and go up a size so it can handle more current safely.

If you don't want to run a separate line, there is a trick/hack you could do.
*CAUTION* Find another circuit that is on the same hot leg as your shop circuit. Then, run an extension cord from there to your shop. And finally, wire in the hots, neutrals and ground together into a new power receptacle. This will effectively allow the load to be shared between different breakers/fuses. But it is absolutely imperative you make sure they are on the same hot leg coming out of the breaker/fuse panel. Otherwise, you could end up with a smoldering bits.
 
Sorry I'm not clear.. Well I'm not a native speaker/writer :D.

I had to use google to find the difference :D.

They are "breakers that trip".
My parents house is a old house with upgraded circuit breakers (We still say it's" the Fusebox").
The main fuse (yes actual fuse) before the circuit breaker-board is 30A so I don't want to exceed this by combining 2 16A breakers.

So I'm going to get a new breaker that is"slower" and see what happens. Or go for some 20A..
 
Ahhh, gotcha. that makes sense. What you could do is put an amp meter/probe to see how much current the welder is really pulling. That way you could see if the breaker is weak (tripping before 16amps), or if the welder is just over the breakers limit.
If the welder is going over, you do not, repeat, do NOT, install a larger breaker in the box on the same wiring. That reason that breaker is in there of that size is because the wiring can't handle a larger load. If you put a 20A breaker on 14 awg wire (1.6mm) you will over heat the wire and possibly start a fire.
However, if you check the wiring and it's 12 awg (2mm), then you can safely use a 20Amp breaker.


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Thanks for the advise. I'm going to take a look what wiring we have. I suspect its al 1.3mm.
I might end up placing an thick wire with a 25A breaker just for the spot welder.

Edit: the wire's at home are 1.7mm thick..
 
So the 14 gauge wire. Max amp draw is 16. So the breakers are sized correctly for the house wiring. (didn't notice till just now that the image of the amps/gauge didn't have 14; but u can see it's less than 20amps)
So you'd have to run a second line for the welder.

Altho, here's a theory. If you are plugging into the shop/rooms wiring, what else is also on the circuit? If you have lights/fans/etc, that could be what's putting you over the limit. If you just connected to another circuit that didn't have anything turned on, then you might be able to get away with the installed wiring. Though, old houses did tend to wire a lot on one circuit. Maybe the bathroom circuit is on it's own line and you could come from there (if it's close enough).
 
still working on a proper electrical installation to get the spot welder working in good order.
In the mean time I installed my "battery assembly line" :cool:

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15 packs of 36 (6x6) Cells ready now for welding/soldering.


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