Actually before soldering I think you should first sand the end of the cell,2 clean the end of the cell, 3 apply flux, and then apply a bit of solder on the end of the cell. That way it would take less time for the tin to stick to the cell and you would not get a cold solder
Hydrochloric acid soldering flux....It doesnt need to be warm to touch before it bonds beyond perfection. All these machines but bro doesnt even know how to solder. Only reason why welding is preferred is because it can be fully automated while soldering requires skill and slightly more knowledge Just need to clean the battery pack afterwards or else it will oxidize because the cell casings are made out of cheap nickel plated A3 steel
Been soldering 50 years. Batteries in freezer, massive 120W soldering iron (big weight of copper tip) Just before soldering light rub with 800 grit on cell end, wipe isopropol apply liquid/paste flux, always wipe soldering iron on damp cloth then tin then move directly to cell and feed in solder. Thats the fastest way. but you wont beat spot weld. Interesting test....... Run a soldered cell next to a welded cell under thermal camera with high load see which joint has the lowest resistance.
For best results when using the soldering iron(40w)... use 200 grit sandpaper to gently rough up the surface of the battery terminals, use at least 91% isopropyl alcohol to thoroughly clean the surfaces, apply a thin coat of paste flux to the battery terminals, then solder, the process should last less then 3sec for maximum affectiveness.
Yeaaahh... reeeeally good idea showing both methods on thermal camera!!! As a professional battery maker, I normally spot weld everything but when I have to solder (discharge/charge and balancing wires) I quickly use a "freezing spray" to cool the soldered area down, instantly stopping the heat from spreading. I also use some spot welding techniques that makes the final soldering step a lot easier and with a lot less heat transferred to the cells. When soldering, to avoid these big solder blobs, leave the soldering iron on until you see the solder spreading and sticking to the surface. This is when a powerful soldering iron makes a difference transferring the heat a lot faster, making the surface hot enough to melt the solder but fast enough to minimise the heat spreading along and inside the cell. *for those people looking for a cheap but reasonably good and flexible spot welder, I highly recommend the Sunkko 709a or above. There are some DIY Arduino ones but it's more complicated requiring a bit more experience. Enough blablabla... I absolutely LOOOOVED this video mate, well done!!!
Just one question: If I follow this method I would be heating the cell quickly and then cooling quickly. Wouldn't this thermal excursion affect the battery chemistry as well?
wouldnt a "profesional battery maker" know you dont have to solder balance leads because you can just solder to a nickel tab then spot weld that tab on to the battery.
@dbright yep. obviously some kid who thinks he knows what he is doing but has no clue. the real shame is 41 people liked it. thats 41 people that have beeen lied to and dont know it and are now dumber because of this kids BS
I'm very happy with my Vruzend kit. I'm skilled at soldering, but didn't want to damage the already cheap cells I'm using. They go together easily, and hold securely. For high vibration areas, like my bike, they have screw-together rods, to keep everything snug, and in contact. Definitely worth the price! Thanks for introducing me to this kit!
After prepping your surface you don't even have to touch the cell with the iron. You use the solder to transfer the heat. To do this you put your iron near the battery and allow the solder to "pool up" between the iron and the battery. This method not only keeps the heat minimal it is also very quick and strong enough to hold together through the extreme vibration and shock that you can expect to endure in EV applications.
@@DieselRamcharger Most of guys working in electronics doesn't have welder unless he works very often with batteries, but almost everyone has proper soldering iron. I've been soldering batteries for few years now and not single one failed. I usually do capacity test of whole pack (i don't do huge packs) and there i 0 degradation to capacity. None of the packs failed so far. So i would say unless you are really bad at soldering, it's not that bad. Welding is obviously much better but it requires huge upfront costs (unless you get one of those cheap welders that won't weld properly and can actually damage battery more than you would with soldering iron).
Spot welding is better, nobody will argue. But if you do not have access to a spot welder, and you must solder, all I'm saying that some rubbing with sanding paper and some proper flux, makes hell of a difference.
Excellent experiment ! I'm so glad I found the Vruzend kit before proceeding with my project. Use of liquid rosin flux might promote wetting. It looks like your tip was around 330C / 630F which is actually about 50C/100F lower than I've seen recommended. And 3 seconds would also be at the lower end of contact for videos I've seen. So I think your results are best case. That said, the thermal conductivity of A3 steel would be around 40-50 W/mC versus the stuff inside the cell at probably in the 0.1 W/mC range, So, as you said, the case temperature doesn't tell us exactly how much the temperature of the contents is elevated versus heat dissipation to the surrounding air. (Maybe tabs could be soldered on individual cells using an aluminum or copper heat sink ring around the case near the electrode (with the upper surface insulated) to draw heat out of the case more effectively.) At the anode, however, it is far less clear where the heat is going or what the effects may be. But my take away is clearly that spot welding is preferable to soldering and that Vruzend is preferable to both when geometric considerations in the pack are not a determining factor. Nice work!
What worked for me really well is using ice from fridge to quickly cool batteries down. Also, as was already mentioned here, make sure to prepare the surface using sand paper. I doubt there will be any damage to the battery if following those tips.
I recall a presentation by Mr Carlson’s Lab, where he demonstrates some good practices of soldering connections. The things I remember are all for shortening the heating time. Start with cleaning the ends of the battery, use some fairly aggressive flux and a high temperature iron tip to prepare the pre-solder. Immediately after cool the cell end with a wet sponge or rag. The heat time can be down to barely more than 1 second. He used wires rather than ribbon in the next step, ends pre-soldered and again the heat time was just about 1 second. With a quick wet sponge coolin the total heat exposure was maybe 4 seconds. I am all in favor of spot welding, but must recognize that the soldering can be acceptable, when done properly.
Can you do a re test by first testing the capacities before and after the soldering vs spot welding to compare the capacity loss? Also hit the solder cells with a Dremel tool, use flux, also a temp controlled soldering iron (Hako or equivalent) will reduce the time necessary for a good joint. Great videos Thanks
For soldering I developed a habit of using a circular motion while making contact. I think it helps with getting the wet look instead of a bead. This work if you're not using a monster tip like Daniel. Something in between. Thanks for another Great video.
It would be interesting to see a thermal camera view of cells connected by each of these three methods when they are discharged at the maximum permissible continuous rate. I did a test with two Samsung 30Q cells discharged at 15 amps, and by the time they were down to 3 volts the soldered cell was about 10 degrees cooler. The soldered cell gave a voltage 0.2 volt higher during the discharge, the reason being that the nickel tabs on the spot-welded cell had so much resistance that they were dropping 0.1 volt each. At 15 amps this is 3 watts of extra heat transmitted into the cell, and 3W x 12 minutes = 0.6 watt-hours of the cell's approx 10 watt-hours (that is 6% of its capacity) not delivered to the load. At lower currents the difference will not be as large; at higher currents that some cells can give, the difference will be larger. I agree with the comments below about sandpapering the cell before soldering: the solder wets the surface much faster if you do. You can get solder made of 62% tin, 36% lead and 2% silver, that melts at 177 degrees C instead of 183 degrees for 60/40 solder.
I really liked the Video, well done and informative. I'm a motorized bike builder. It should be called engineized because mine run on gasoline. I do make all the lighting and charging components from discarded electronics. I tried to solder some li-ion cells together, but the heat made me nervous. I'm now collecting components to build a spot welder just for the purpose of building multi cell battery packs. I wish I would have had some of the NO solder/weld pieces. What a GREAT idea. I'll have to check into those. Thanks for the video, I know I'll wait until I finish my spot welder. Thanks again, Daniel.
I like to keep my soldering iron at around 420c. I also make it a point to use thin solder wire. That makes it easier to control. Typically i aim for 3 seconds, but it normally solders in 2. Keeping the heat this high helps with the heat distribution on the battery. Great Video and one of my all time favorites!!!
Even a corrosion resistant metal grows an oxide layer over time, so I figure it's better to sand that off first with a hard abrasive, then add flux, etc.
Cool that you did this scientifically. For soldering, the proper way to do this is roughen the surface with fine sandpaper, lots of solder paste using an SMD stencil with a large ground pad rather than wire solder, preheat the bus wire, 1 second or less heat time on very high followed by spraying with isopropyl alcohol to cool and remove flux residue.
I wonder if the heat observed traveling "into" the cell was heat traveling along the exterior metal case of the cell? Especially when you consider how quickly the heat dissipates.
It really true that most DIY lithium ion battery makers use soldering systems because of costs of the spot welders and there are heating damages to the batteries in one way or the other. The cheaper hand spot welders are of not much use as the nickel strips peel off as soon as the welding are done thereby leading to repeated spot welding of the same batteries with defaced ends.I have tried both on a number of occasions and end up unable to determine which method is more effective ! I think the spot welding companies, if they are watching, should find a better means of producing highly effective and yet cheap enough portable hand spot welders for the international markets.Reflective metals generally interfare with infrared camera ability to monitor and detect heat radiations but all the same, your teaching/demonstration is very good in reiterating the importance of not imparting too much of heat into the lithium ion batteries if damages and accidents are to be avoided in the future. Once again, thank you Micah…..(Joseph Oshagbemi ).
5:40 the word you are looking for is filet. A proper solder joint has a clearly observable filet. From some one who took Avionics Soldering at a college that specializes in it.
I use flux paste directly on the solder site and also scrape the surface where the solder is to meet. A big tip is not necessary, as the main thing is to have a high temp (400 C) to start the wetting quick. once wetting starts it carries along quite easily. I personally prefer a needle tip, as you can get a small area to start wetting within 1 second with ease and then use the broad side of the needle tip to quickly spread it out while feeding solder to the join. But the main point here is the flux paste and high temp really makes a big difference, as It can cut multiple seconds off the time it takes to wet the surface, even if you have flux core. In the wise words of Louis Rossmann, the bigger the gob, the better the job.
Great video As an Electrical engineer, I do not recommend soldering batteries. What I would like to see is a comparison of resistance in milli-ohms of each method of connection and the voltage drop on the same size battery packs. Can you weld copper bus bars ?
Since you claim to be an electrical engineer why do recommend not soldering? Are you saying this from reading comment? Rumors? Personal experience? The reason I ask is I have been soldering on these cells for years. I have done extreme testing with welding vs soldering and I cant seem to create any damage to the IR. I have not seen any capacity difference or long time effect. Please explain why you do NOT recommend.
The components inside never got above 70C even though the camera showed 200C for the solder blob sat on the outside of the case. You know this by how quickly the surface temperature dropped, back below 50C in 5 seconds. 70C would have no affect on the reliability or capacity of the cells. And if this guy had done it properly, sand, flux, powerful iron turned to max, it would have taken less than a second to get a perfect patch of solder limiting internal temperatures more. Yes a welder is better than solder but if you're only doing a few cells occasionally it's a total waste of money.
I am addicted to watching your videos. Thanks for the information. I'm also working on a "solar" ebike charger. it is more complicated than i anticipated and the "locals" really don't know anything about MPPT Boost/Charge controllers to make it happen.. Then they wonder why I shop outside the USA.. (little sarcasm)
Seems he should add some flux ontop of the cell first it tends to help getting the solder to bond with the cells when i do it even doh my solder got flux inside of it.
Thanks I had gone to a few sites. Using the camera to see heat transferring into the cell convinced me to do spot weld. I already bought your book on amazon. On the batterys. But not the bike one.
I liked you video and the idea behind it. While watching a though came into my mind. I understand with whatever method of cell to cell attachment is used effort should be make to not expose the cells to too much heat and heat retention. I was wondering if you in a controlled slow manner dropped the temperature of the cells down around 60 or 50 degrees Fahrenheit would the attachment still achieve the same strength bond while not subjecting the lithium cell to a high a temperature. I do not know if starting with a lower temperature cell would cause any difficulties with the internal chemistry. Have you ever heard of anyone doing this type of starting temperature experiment link you did in this video. Would you consider doing a follow up experiment with this idea? This was great I really appreciated how you went back in post production and added the high temps.
Good to see those temps. I am using a 4s2p on my Vintage Racing Motorcycle to power the ignition and I wanted to make a couple more batteries to have on hand at the track.
Would using tin-bismuth solder work better as its melting point is 138C'. My concern is that in my application of an e-bike running at 50V and 20amps so 1kW this may be dangerously close and may start to effect the mechanical properties of the solder.
Great and clear visual battery experiment! As we talk in the sphere there is no doubt that spot welding is one of the best welding method , just don't completely discard iron soldering 18650 cells. The chemistry harming when permanent loss of capacity is involved depends of an equation between temperature and time. So even if the cell surface shows >200°C, the greater inner cell volume reaches much less temperature and during a insignificant duration. When the soldering involves a very high temperature and a very short time (a little more powerful iron and slightly greater tip mass), the harming will be negligible. The thermal imagine image makes it looks very dramatic indeed!, but total volume reaching high temperature is less than it looks. If I have the time I will make a energy test comparison between a spot welded battery vs iron soldering battery with the similar standard iron, 18650 science! :D
According to one of the gentleman whose name appears on the patent you should not under any circumstances solder these cells.... straight from the horses mouth outranks anyone else's opinion as far as I'm concerned, he convinced me very quickly!
I'm agree, is not a professional way to do it. The most vulnerable elements are both current interrupt device and positive temperature coeficient membrane near the anode lead, both are vulnerable to rise the cell IR permanently under high temperatures, but those are luckily enough separated to the anode disc, making soldering the anode relatively safe. For other considerations, 18650 cells are elements designed to work on high temperatures, if you know how to solder them, using high quality cells, the consideration could be not more than a slightly loss of capacity. I never solder cells, and I think is the worst way to connect them (not worse than contact systems) but I couldn't deny is a way to do it if you know what are you doing
Hi, very late for a comment about your very interesting video! 👍👍 I agree , spot-welding is the best for all common uses ...except for high amps drain (motorcycle etc...). In this case bus-bars are the best but not always possible, so I use copper wire and solder with minimum 80/100w iron for a shortest soldering time : maximal contact , and it's the best solution to drain 100A or more in a few seconds. Be simply sure that all weldings have the same quality to avoid hot points and quick issues on the cells. For the beginners : don't do that if you don't know amps issues.
I agree with the other comments to clean the battery tips with a low grit sandpaper, or steel wool, and the nickel strip and to use a flux for the solder approach. The solderless caps seem novel so I am going to put a like on this vid. Good job!
What about pre-cooling the cells in a fridge for a couple of hours before soldering ? That way the core of the battery will be cooled to about a temp of 40F, preventing the core from rising above normal even with the excess soldering heat.
Neeraj नीरज Tulsian तुलसियान nono no. Bad idea. You will create high temperature differe ce that leads to sudden expansion that increase the risk of explosion, or just triggered one.
@@stanleymichelim4326 Has an explosion actually happened to you? I doubt it. We already have a very high temperature differential ! Chilling the cell does not increase the temperate differential very much, but does COOL the cell.
Combat engineer also has a good video about soldering the Cells with Solder iron. But you also need to place Flux on top of the cells surface for a good clean solder. And of course use Low Temp solder tin-lead like you did. That solder melts at about 180C-190C. No need to place the Solder iron at 300. Nice video.
I can see why you don't like soldering the batteries. I also know several methods to make soldering better and faster. Sand the top, apply solder to the iron, not the battery, add additional flux. Also there is a soldering wire that is Sn/Bi that melts at 140C rather than the 183C of leaded solder. A soldering tip at 160 will let a lot less heat into the cell than 200 of Sn/Pb. I have also seen fuse wire being welded to batteries. Combined with copper buss bars, I think you can get the safety of the fuses and the lower resistance of copper to increase the efficiency of your system. Plus its going to be easier than welding strip over strip of nickel wire. Is there going to be a follow up on the capacity / cycle life of both welded and soldered batteries in reference to your mechanical solution? Just finished reading your book, it is a good general overview of what all that you need to build battery banks.
On some of the 18650 soldering videos I've seen, they rough up the battery ends like you would if you were soldering a coupler on a copper pipe. It makes sense because it takes the solder much faster.
If you are going to weld batteries make sure it's the kind of spot welder where both tips can come from the same direction - some of the sheet metal spot welders come from top and bottom of the weld not like what you see him doing! If you use a sheet metal spot welder (top/bottom) you can easily BLOW UP and 18650 or any small battery for that matter. because the welding current is induced through the battery to make the weld which will destroy the cell and probably rupture it. just a word of caution! :)
Great to see this comparison. Would you be willing to do one more test? I use recycled laptop cells that I keep in their pairs. So I'm only applying heat to the nickel strip between the pairs. I'd love to see how much effect that has on the amount of heat transferred compared to the two methods you tested here. Within the DIY Powerwall community (not your core audience I understand) we're wanting to attach "Tesla style" fuses to each cell. Are you able to do that with your spot welder? And lastly - soldering is a skill that takes a while to get good at. Watching you solder was a wee bit like watching Jehu test the Vruzend system without any practice. :/
Great Video, But A 100-watt soldering iron from what I can tell is better than the 50-75w when soldering cells(bigger tip and more heat). I have built a few battery tab welders with an MOT. Would be interesting to see how hot those get. Just curious, not sure if i missed it in the video, what you had the soldering set at? Also what settings you had the tab welder set at? I had no clue the differences in the heat, great to see you guys do a video on it! Very educational!👍👍👍 Edit-Just seen the iron at 330C with the thermal camera.
Hi, I like you video for many reasons. You video is the only one, so far that I've seen, that actually illustrates what is happening to the battery cell, and how far heat penetrates. I also like the video overlay you do with the thermal video. My question is: What video software are you using to produce this video? I love how you overlaid the thermal video and then enlarged. Thanks!
One way to keep things cool I've used is to wrap the cells in wet wipes. I also spot weld first, then solder to the nickel strip in-between the cells. See this for details: ua-cam.com/video/JM3Sqll5n00/v-deo.html Cheers
Try using a straw to blow cool air onto the battery whilst soldering, preferably in a cool environment. And as others have mentioned, prep the area first with fine grit sandpaper then flux.
Sorry, have tried to use both methods, solder and spot welding. The soldered batteries don’t show immediate damage but after repeated usage then do not seem to last very long. Only difference between the two methods of joining is heat. The heat does indeed cause battery damage. The spot welded batteries last far longer because the spot weld does not transfer very much heat into the battery. Over time concentrated heat joints just kill 18650 Li-ion batteries. Case closed.
hi maiky. will you please give us an idea about the mid drive kit? and maybe comparison with hub motors from your point of view.. i would really appreciated..
It is really hard to solder to the negative terminal, due to the size of it and it spreads the heat out the length of the terminal and that goes the length of the battery. I had too many break off and I had to open the pack up to fix it. Once I purchased a spot welder I have never had an issue again. Spot welding is the way to go.
A further experiment would be to measure the capacitance of a couple of cells (record them) and then use both methods and see if the capacity of the cell changes.
Ok it heats up but what are the consequences? Does the capacity of the cell decrease? Could you do a before and after capacity test to see what's the difference ?
Thank you very much for doing this! I was wondering myself: I have read and watched different videos on this and the best way to see the truth is to experiment! :)
Wondering about the current capacity of tabbed cells with a single pair of welds, or even two pairs? The conductivity of soldered VS welded? With the FLIR, would be interested to see if a tab welded with a single pair of welds would heat up under a heavy current draw.
I discovered by accident that covering the area you want to solder with a black Sharpie marker helps the solder wet out a bit better, it might be that the solvent in the pen cleans the area.
If you sanded the battery with some emery paper then used some good flux, the solder would definitely adhere much better and quicker. But, spot welding is definitely the choice when connecting 18650's or any battery.
I really like your videos, but while soldering carries more risk, you are using a medium sized tip, with a not very big iron, and you didn't sand the contacts beforehand. Using a bigger tip, a bigger more powerful soldering iron while using sanding the contact and spreading flux on it, I can easily solder within a max of 2 seconds after some practice on completely dead cells. You probably could do it in 1.5 seconds with much more practice. Your method is basic and could use some refinement, especially as cells don't like excessive heat as you might know :D
@@neutronpcxt372 it doesnt matter what prep work you do the item you are soldering still has to get to the melting temp of the solder or you wont have a good joint and that goes for all forms of soldering not just electrical soldering
@@bjorn1583 Yes, but with a massive iron that has a large tip with a lot of surface area, the solder can liquefy extremely quickly, and stick extremely well.
I am so glad there are youtubers who know the term "Wetting" when it comes to Solder. I've seen so many youtubers soldering and I nearly laugh or cry or vomit at how awful their idea of soldering really is. Thank you for being educated in proper soldering terms and practices.
There are two main reasons why the manufacture uses a spot welder. First its the fastest/most efficient way to make a battery pack. Second is very high drain current produces heat that can melt the tin on the tab and diconnect the wire/nickel plate. Any electronic devices with high current consumption or current path use mechanical contact and not soldered.
Cool video thx for sharing . I thinking Flux would of helped you think ? maybe light scuffing of the cell metal that is to be tinned? Love the spot welding machine what metal strip was that you spot welded with ? Thx
you are right. But the spot also does a high temperature. If you look at the video at slow speed, you will see that the temperature repeatedly reaches 184 degrees Celsius.
Yes that was a good demo - and making your own eBike is a great project. I'd still prefer my www.flx.bike though. I'm using the cell welding for a different project - Thanks for the video.
I think everyone knows that spot welding is better. The major concern is how soldering affects the capacity and at what temperature&second it will be dangerous
Spot welding is NOT better. Maybe a little safer? Yes, but deff not better. The spot welds are trash, you could never trust them on a critical project. They hold just enough. When using these cells for high current applications then the nickel strips just can't hold up compared to a heavy gauge wire that has been soldered directly. Yes, i know your comment is from 3 years ago but nothing has changed.
When soldering those kind of thing you want a soldering iron of atleas 100W and apply some flux paste on where you want to solder sins chrome or what there those terminal are made out of don't like solder sticking to it very well. BTW what thermal camera is it and where did you buy it from?
NeutronPCXT doesnt look like the smartphone flir and the next step would also look bad and cost around 2000$ but this one looks good enough for what I need so I was just wondering
I think its proven that soldering doesnt really hurt the cell if you do high heat for 4 or less seconds. My question would be how the voltage transfer is different between a spot welld and a solder joint. seems like the solder would be better. SPot welds seem to break off more often?
very interesting, i was sort of trying to decide if i could get away with not having a spot welder... maybe reviews of spot welders would be helpful? i see them on amazon for ~150
Even if it’s not a perfect test (let say in real condition) set up you made your point and that’s what I like about your video. Keep it simple KIS. You must be a teacher or have the talent for ... :-)
Is spot welding safe for your eyes? Do you look at it directly? Ordinary arc welding requires a full face shield for safety. Isn't this the same principle, just on a smaller scale?
Hi, would be good to see how hot it gets using the smaller soldering iron. Also, when you show the thermal image and it get's hot, how do you correlate that to potential damage. The heat may only be locally affecting the battery but may not hurt the perfomance later. Would be good to show some performance check.
We must know what is inside the battery cells (solid, liquid, chemistry, etc.) and think about their reaction when being heated on that temp. Personally, I believe applying that heat will shorten the lifetime of the battery cells, PCMIIW. Maybe that's one of the reasons the manufacturers using spot welding instead of soldering?
Clean where you want to soldier first then put some soldier pasta on it to help. Then the more power your soldering iron has the faster you can solder it and the less time the heat has to move down. They make tools to use when soldering,, one has a small steal brush to clean and ruff up where you soldier. This helps the heat move to the place you want to soldier.
Bottom line that solder melts at 188C. So it's above that. If soldering, you might use copper ribbon. Nickel has no advantage for solder and copper has less resistance.
The 60/40 solder melts at over 180C, and both the solder and the surface underneath must get at least that hot to get a good joint. So nobody should be surprised to see a very hot spot in the camera after removing the soldering tip. The important question is how much of that heat energy manages to move into the guts of the cell where the plastic seals and sensitive chemicals are, and the camera cannot show that. If you want to reduce the chance of internal damage, why not cool the cells in the refrigerator for some time before soldering? One thing I would like to see tested is which cell joining method is more resistant to vibrations. I would like to see the solder-less method included in this test. That would be important for e-bike applications but not so much for power wall applications. Could you make a video showing how hot the cell gets while it is being wrapped in heat shrink tubing? I think some people will be freaked out by the findings ;-). One thing I don't understand is people using nickel strips when soldering cells. The strip is the way to go when spot welding, but if I was soldering I would use only copper wire. Nickel strip is not only expensive but it is a poor conductor of electricity compared to copper.
You had one job! And I could have added a bunch more since the thermal cam was up. Test #1 bridge the gap between the + & - h a cooler more efficient way when your phones case is compared to leaving all my electro bug GNG o
There are many available. Good ones for less than $100. I have a one-handed rechargable that I've used to make welds on about 200 cells. I have never had a spot weld fail. I never solder onto the battery. When welding leads, I solder them to the heavy nickel strip first and then spot weld to the battery.
Actually before soldering I think you should first sand the end of the cell,2 clean the end of the cell, 3 apply flux, and then apply a bit of solder on the end of the cell. That way it would take less time for the tin to stick to the cell and you would not get a cold solder
Hydrochloric acid soldering flux....It doesnt need to be warm to touch before it bonds beyond perfection. All these machines but bro doesnt even know how to solder.
Only reason why welding is preferred is because it can be fully automated while soldering requires skill and slightly more knowledge
Just need to clean the battery pack afterwards or else it will oxidize because the cell casings are made out of cheap nickel plated A3 steel
Been soldering 50 years. Batteries in freezer, massive 120W soldering iron (big weight of copper tip) Just before soldering light rub with 800 grit on cell end, wipe isopropol apply liquid/paste flux, always wipe soldering iron on damp cloth then tin then move directly to cell and feed in solder. Thats the fastest way. but you wont beat spot weld.
Interesting test....... Run a soldered cell next to a welded cell under thermal camera with high load see which joint has the lowest resistance.
For best results when using the soldering iron(40w)... use 200 grit sandpaper to gently rough up the surface of the battery terminals, use at least 91% isopropyl alcohol to thoroughly clean the surfaces, apply a thin coat of paste flux to the battery terminals, then solder, the process should last less then 3sec for maximum affectiveness.
I was also thinking about slightly sanding up the surface
Yeaaahh... reeeeally good idea showing both methods on thermal camera!!!
As a professional battery maker, I normally spot weld everything but when I have to solder (discharge/charge and balancing wires) I quickly use a "freezing spray" to cool the soldered area down, instantly stopping the heat from spreading. I also use some spot welding techniques that makes the final soldering step a lot easier and with a lot less heat transferred to the cells.
When soldering, to avoid these big solder blobs, leave the soldering iron on until you see the solder spreading and sticking to the surface. This is when a powerful soldering iron makes a difference transferring the heat a lot faster, making the surface hot enough to melt the solder but fast enough to minimise the heat spreading along and inside the cell.
*for those people looking for a cheap but reasonably good and flexible spot welder, I highly recommend the Sunkko 709a or above. There are some DIY Arduino ones but it's more complicated requiring a bit more experience.
Enough blablabla... I absolutely LOOOOVED this video mate, well done!!!
hey!!! long time no see!
POOOOWEEER!!! :D
Just one question: If I follow this method I would be heating the cell quickly and then cooling quickly. Wouldn't this thermal excursion affect the battery chemistry as well?
wouldnt a "profesional battery maker" know you dont have to solder balance leads because you can just solder to a nickel tab then spot weld that tab on to the battery.
@dbright yep. obviously some kid who thinks he knows what he is doing but has no clue. the real shame is 41 people liked it. thats 41 people that have beeen lied to and dont know it and are now dumber because of this kids BS
I have an electrician for many years and am retired now but there is always something new to learn about the power industry. Thanks for sharing!
I'm very happy with my Vruzend kit. I'm skilled at soldering, but didn't want to damage the already cheap cells I'm using. They go together easily, and hold securely. For high vibration areas, like my bike, they have screw-together rods, to keep everything snug, and in contact. Definitely worth the price! Thanks for introducing me to this kit!
After prepping your surface you don't even have to touch the cell with the iron. You use the solder to transfer the heat. To do this you put your iron near the battery and allow the solder to "pool up" between the iron and the battery. This method not only keeps the heat minimal it is also very quick and strong enough to hold together through the extreme vibration and shock that you can expect to endure in EV applications.
Thank you. I totally second using the melted solder to touch the plate instead.
In addition to all of the above. A wet sponge aftera solder joint also helps resist heat transfer
3:50 is where the intro ends
Try using some sanding paper before soldering to roughfen up the surface of the cell, extra flux and a bigger soldering iron. Much beter results
soldering lithium batteries is for fucking morons.
@@DieselRamcharger Most of guys working in electronics doesn't have welder unless he works very often with batteries, but almost everyone has proper soldering iron. I've been soldering batteries for few years now and not single one failed. I usually do capacity test of whole pack (i don't do huge packs) and there i 0 degradation to capacity. None of the packs failed so far. So i would say unless you are really bad at soldering, it's not that bad. Welding is obviously much better but it requires huge upfront costs (unless you get one of those cheap welders that won't weld properly and can actually damage battery more than you would with soldering iron).
If you want to deteriorate your battery then do it
Do you work at spotweld company? May you share your resources to your co tech .(standard)
Spot welding is better, nobody will argue. But if you do not have access to a spot welder, and you must solder, all I'm saying that some rubbing with sanding paper and some proper flux, makes hell of a difference.
Excellent experiment ! I'm so glad I found the Vruzend kit before proceeding with my project. Use of liquid rosin flux might promote wetting. It looks like your tip was around 330C / 630F which is actually about 50C/100F lower than I've seen recommended. And 3 seconds would also be at the lower end of contact for videos I've seen. So I think your results are best case. That said, the thermal conductivity of A3 steel would be around 40-50 W/mC versus the stuff inside the cell at probably in the 0.1 W/mC range, So, as you said, the case temperature doesn't tell us exactly how much the temperature of the contents is elevated versus heat dissipation to the surrounding air. (Maybe tabs could be soldered on individual cells using an aluminum or copper heat sink ring around the case near the electrode (with the upper surface insulated) to draw heat out of the case more effectively.) At the anode, however, it is far less clear where the heat is going or what the effects may be. But my take away is clearly that spot welding is preferable to soldering and that Vruzend is preferable to both when geometric considerations in the pack are not a determining factor. Nice work!
What worked for me really well is using ice from fridge to quickly cool batteries down. Also, as was already mentioned here, make sure to prepare the surface using sand paper. I doubt there will be any damage to the battery if following those tips.
I recall a presentation by Mr Carlson’s Lab, where he demonstrates some good practices of soldering connections.
The things I remember are all for shortening the heating time. Start with cleaning the ends of the battery, use some fairly aggressive flux and a high temperature iron tip to prepare the pre-solder. Immediately after cool the cell end with a wet sponge or rag. The heat time can be down to barely more than 1 second. He used wires rather than ribbon in the next step, ends pre-soldered and again the heat time was just about 1 second. With a quick wet sponge coolin the total heat exposure was maybe 4 seconds.
I am all in favor of spot welding, but must recognize that the soldering can be acceptable, when done properly.
Mr Carlson's Lab, Best electronics teacher on UA-cam
you can not solder a lipo safely. period.
Can you do a re test by first testing the capacities before and after the soldering vs spot welding to compare the capacity loss?
Also hit the solder cells with a Dremel tool, use flux, also a temp controlled soldering iron (Hako or equivalent) will reduce the time necessary for a good joint.
Great videos Thanks
with the cost of a decent soldering iron you can buy a spot welder, even better make your own spot welder out of a car battery
@@bjorn1583 not true. the blue $8 soldering irons on amazon work just fine, but i agree with the second part.
For soldering I developed a habit of using a circular motion while making contact. I think it helps with getting the wet look instead of a bead. This work if you're not using a monster tip like Daniel. Something in between. Thanks for another Great video.
It would be interesting to see a thermal camera view of cells connected by each of these three methods when they are discharged at the maximum permissible continuous rate. I did a test with two Samsung 30Q cells discharged at 15 amps, and by the time they were down to 3 volts the soldered cell was about 10 degrees cooler. The soldered cell gave a voltage 0.2 volt higher during the discharge, the reason being that the nickel tabs on the spot-welded cell had so much resistance that they were dropping 0.1 volt each. At 15 amps this is 3 watts of extra heat transmitted into the cell, and 3W x 12 minutes = 0.6 watt-hours of the cell's approx 10 watt-hours (that is 6% of its capacity) not delivered to the load. At lower currents the difference will not be as large; at higher currents that some cells can give, the difference will be larger. I agree with the comments below about sandpapering the cell before soldering: the solder wets the surface much faster if you do. You can get solder made of 62% tin, 36% lead and 2% silver, that melts at 177 degrees C instead of 183 degrees for 60/40 solder.
I really liked the Video, well done and informative. I'm a motorized bike builder. It should be called engineized because mine
run on gasoline. I do make all the lighting and charging components from discarded electronics. I tried to solder some li-ion cells together, but the heat made me nervous. I'm now collecting components to build a spot welder just for the purpose of building multi cell battery packs. I wish I would have had some of the NO solder/weld pieces. What a GREAT idea. I'll have to check into those. Thanks for the video, I know I'll wait until I finish my spot welder. Thanks again, Daniel.
I suggest using flux paste also to reduce the contact time while soldering or sanding the battery surface first
I like to keep my soldering iron at around 420c. I also make it a point to use thin solder wire. That makes it easier to control. Typically i aim for 3 seconds, but it normally solders in 2. Keeping the heat this high helps with the heat distribution on the battery. Great Video and one of my all time favorites!!!
Even a corrosion resistant metal grows an oxide layer over time, so I figure it's better to sand that off first with a hard abrasive, then add flux, etc.
Cool that you did this scientifically. For soldering, the proper way to do this is roughen the surface with fine sandpaper, lots of solder paste using an SMD stencil with a large ground pad rather than wire solder, preheat the bus wire, 1 second or less heat time on very high followed by spraying with isopropyl alcohol to cool and remove flux residue.
WoW great advice
Great video! Thank you so much for your project!
would you be able to test if the cell capacity changes after soldering?
I wonder if the heat observed traveling "into" the cell was heat traveling along the exterior metal case of the cell? Especially when you consider how quickly the heat dissipates.
It really true that most DIY lithium ion battery makers use soldering systems because of costs of the spot welders and there are heating damages to the batteries in one way or the other. The cheaper hand spot welders are of not much use as the nickel strips peel off as soon as the welding are done thereby leading to repeated spot welding of the same batteries with defaced ends.I have tried both on a number of occasions and end up unable to determine which method is more effective ! I think the spot welding companies, if they are watching, should find a better means of producing highly effective and yet cheap enough portable hand spot welders for the international markets.Reflective metals generally interfare with infrared camera ability to monitor and detect heat radiations but all the same, your teaching/demonstration is very good in reiterating the importance of not imparting too much of heat into the lithium ion batteries if damages and accidents are to be avoided in the future. Once again, thank you Micah…..(Joseph Oshagbemi ).
5:40 the word you are looking for is filet. A proper solder joint has a clearly observable filet. From some one who took Avionics Soldering at a college that specializes in it.
PS 63/37 rosin core solder will work better and a dab of flux prior will give better results. Love this idea for a vid as I haven't seen it on YT yet.
Spot on but what’s the resistance between cell and soldered strip and cell and spot welded strip?
I use flux paste directly on the solder site and also scrape the surface where the solder is to meet. A big tip is not necessary, as the main thing is to have a high temp (400 C) to start the wetting quick. once wetting starts it carries along quite easily. I personally prefer a needle tip, as you can get a small area to start wetting within 1 second with ease and then use the broad side of the needle tip to quickly spread it out while feeding solder to the join. But the main point here is the flux paste and high temp really makes a big difference, as It can cut multiple seconds off the time it takes to wet the surface, even if you have flux core. In the wise words of Louis Rossmann, the bigger the gob, the better the job.
Great video As an Electrical engineer, I do not recommend soldering batteries. What I would like to see is a comparison of resistance in milli-ohms of each method of connection and the voltage drop on the same size battery packs. Can you weld copper bus bars ?
Since you claim to be an electrical engineer why do recommend not soldering? Are you saying this from reading comment? Rumors? Personal experience? The reason I ask is I have been soldering on these cells for years. I have done extreme testing with welding vs soldering and I cant seem to create any damage to the IR. I have not seen any capacity difference or long time effect. Please explain why you do NOT recommend.
LOL you solder these cells in 1 second using acid flux and a 80w iron... Done hundreds of them perfectly.
This....
The components inside never got above 70C even though the camera showed 200C for the solder blob sat on the outside of the case. You know this by how quickly the surface temperature dropped, back below 50C in 5 seconds. 70C would have no affect on the reliability or capacity of the cells. And if this guy had done it properly, sand, flux, powerful iron turned to max, it would have taken less than a second to get a perfect patch of solder limiting internal temperatures more. Yes a welder is better than solder but if you're only doing a few cells occasionally it's a total waste of money.
You dont know how to solder actually..
I am addicted to watching your videos. Thanks for the information. I'm also working on a "solar" ebike charger. it is more complicated than i anticipated and the "locals" really don't know anything about MPPT Boost/Charge controllers to make it happen.. Then they wonder why I shop outside the USA.. (little sarcasm)
Seems he should add some flux ontop of the cell first it tends to help getting the solder to bond with the cells when i do it even doh my solder got flux inside of it.
Thanks I had gone to a few sites. Using the camera to see heat transferring into the cell convinced me to do spot weld. I already bought your book on amazon. On the batterys. But not the bike one.
My favourite tool for cleaning a surface prior to soldering is a fibreglass pencil. Be careful of the resulting dust, it can be an irritant.
Try out how much does it actually take to toast the battery :)
100 degrees is danger zone .
I liked you video and the idea behind it. While watching a though came into my mind. I understand with whatever method of cell to cell attachment is used effort should be make to not expose the cells to too much heat and heat retention. I was wondering if you in a controlled slow manner dropped the temperature of the cells down around 60 or 50 degrees Fahrenheit would the attachment still achieve the same strength bond while not subjecting the lithium cell to a high a temperature. I do not know if starting with a lower temperature cell would cause any difficulties with the internal chemistry. Have you ever heard of anyone doing this type of starting temperature experiment link you did in this video. Would you consider doing a follow up experiment with this idea? This was great I really appreciated how you went back in post production and added the high temps.
Good to see those temps. I am using a 4s2p on my Vintage Racing Motorcycle to power the ignition and I wanted to make a couple more batteries to have on hand at the track.
Would using tin-bismuth solder work better as its melting point is 138C'.
My concern is that in my application of an e-bike running at 50V and 20amps so 1kW this may be dangerously close and may start to effect the mechanical properties of the solder.
Great and clear visual battery experiment!
As we talk in the sphere there is no doubt that spot welding is one of the best welding method , just don't completely discard iron soldering 18650 cells. The chemistry harming when permanent loss of capacity is involved depends of an equation between temperature and time. So even if the cell surface shows >200°C, the greater inner cell volume reaches much less temperature and during a insignificant duration. When the soldering involves a very high temperature and a very short time (a little more powerful iron and slightly greater tip mass), the harming will be negligible. The thermal imagine image makes it looks very dramatic indeed!, but total volume reaching high temperature is less than it looks.
If I have the time I will make a energy test comparison between a spot welded battery vs iron soldering battery with the similar standard iron, 18650 science! :D
According to one of the gentleman whose name appears on the patent you should not under any circumstances solder these cells.... straight from the horses mouth outranks anyone else's opinion as far as I'm concerned, he convinced me very quickly!
I'm agree, is not a professional way to do it.
The most vulnerable elements are both current interrupt device and positive temperature coeficient membrane near the anode lead, both are vulnerable to rise the cell IR permanently under high temperatures, but those are luckily enough separated to the anode disc, making soldering the anode relatively safe. For other considerations, 18650 cells are elements designed to work on high temperatures, if you know how to solder them, using high quality cells, the consideration could be not more than a slightly loss of capacity.
I never solder cells, and I think is the worst way to connect them (not worse than contact systems) but I couldn't deny is a way to do it if you know what are you doing
Damian Rene
Prep Cell contacts first , sand terminals and add flux to them and also flux your solder tip
Do you think a bit of scuffing and a small amount of rosin flux would allow the solder joint to be done quicker?
Hi, very late for a comment about your very interesting video! 👍👍
I agree , spot-welding is the best for all common uses ...except for high amps drain (motorcycle etc...). In this case bus-bars are the best but not always possible, so I use copper wire and solder with minimum 80/100w iron for a shortest soldering time : maximal contact , and it's the best solution to drain 100A or more in a few seconds. Be simply sure that all weldings have the same quality to avoid hot points and quick issues on the cells. For the beginners : don't do that if you don't know amps issues.
I agree with the other comments to clean the battery tips with a low grit sandpaper, or steel wool, and the nickel strip and to use a flux for the solder approach. The solderless caps seem novel so I am going to put a like on this vid. Good job!
Flux will help a lot. A little smear of flux will flow the solder like butter...
What about pre-cooling the cells in a fridge for a couple of hours before soldering ?
That way the core of the battery will be cooled to about a temp of 40F, preventing the core from rising above normal even with the excess soldering heat.
Neeraj नीरज Tulsian तुलसियान nono no. Bad idea. You will create high temperature differe ce that leads to sudden expansion that increase the risk of explosion, or just triggered one.
@@stanleymichelim4326 Has an explosion actually happened to you? I doubt it. We already have a very high temperature differential ! Chilling the cell does not increase the temperate differential very much, but does COOL the cell.
Combat engineer also has a good video about soldering the Cells with Solder iron. But you also need to place Flux on top of the cells surface for a good clean solder. And of course use Low Temp solder tin-lead like you did. That solder melts at about 180C-190C. No need to place the Solder iron at 300. Nice video.
I can see why you don't like soldering the batteries. I also know several methods to make soldering better and faster. Sand the top, apply solder to the iron, not the battery, add additional flux. Also there is a soldering wire that is Sn/Bi that melts at 140C rather than the 183C of leaded solder. A soldering tip at 160 will let a lot less heat into the cell than 200 of Sn/Pb.
I have also seen fuse wire being welded to batteries. Combined with copper buss bars, I think you can get the safety of the fuses and the lower resistance of copper to increase the efficiency of your system. Plus its going to be easier than welding strip over strip of nickel wire.
Is there going to be a follow up on the capacity / cycle life of both welded and soldered batteries in reference to your mechanical solution?
Just finished reading your book, it is a good general overview of what all that you need to build battery banks.
On some of the 18650 soldering videos I've seen, they rough up the battery ends like you would if you were soldering a coupler on a copper pipe. It makes sense because it takes the solder much faster.
the battery still has to get to the same temp as the melting point of the solder for it to stick properly
Seeing the heat travel down so fast definitely convinced me to spot weld.
My dad had a spot welder: I'll have to see if I can find it. Great video, loved it.
If you are going to weld batteries make sure it's the kind of spot welder where both tips can come from the same direction - some of the sheet metal spot welders come from top and bottom of the weld not like what you see him doing! If you use a sheet metal spot welder (top/bottom) you can easily BLOW UP and 18650 or any small battery for that matter. because the welding current is induced through the battery to make the weld which will destroy the cell and probably rupture it. just a word of caution! :)
Great to see this comparison. Would you be willing to do one more test? I use recycled laptop cells that I keep in their pairs. So I'm only applying heat to the nickel strip between the pairs. I'd love to see how much effect that has on the amount of heat transferred compared to the two methods you tested here.
Within the DIY Powerwall community (not your core audience I understand) we're wanting to attach "Tesla style" fuses to each cell. Are you able to do that with your spot welder?
And lastly - soldering is a skill that takes a while to get good at. Watching you solder was a wee bit like watching Jehu test the Vruzend system without any practice. :/
Great Video, But A 100-watt soldering iron from what I can tell is better than the 50-75w when soldering cells(bigger tip and more heat). I have built a few battery tab welders with an MOT. Would be interesting to see how hot those get. Just curious, not sure if i missed it in the video, what you had the soldering set at? Also what settings you had the tab welder set at? I had no clue the differences in the heat, great to see you guys do a video on it! Very educational!👍👍👍
Edit-Just seen the iron at 330C with the thermal camera.
Hi, I like you video for many reasons. You video is the only one, so far that I've seen, that actually illustrates what is happening to the battery cell, and how far heat penetrates. I also like the video overlay you do with the thermal video. My question is: What video software are you using to produce this video? I love how you overlaid the thermal video and then enlarged. Thanks!
Could you do a video about the discarge temp of the most used cells (Samsung 30Q, 25R, Sanyo GA, etc)?
Would love to see how these compare!
Yea that would be interesting. I'll try to do some tests. Thanks for the tip!
Great test, huge difference between both tests
One way to keep things cool I've used is to wrap the cells in wet wipes. I also spot weld first, then solder to the nickel strip in-between the cells. See this for details:
ua-cam.com/video/JM3Sqll5n00/v-deo.html
Cheers
Try using a straw to blow cool air onto the battery whilst soldering, preferably in a cool environment. And as others have mentioned, prep the area first with fine grit sandpaper then flux.
I highly recommend His DYI Lithium Battery book. It is very informative.
Sorry, have tried to use both methods, solder and spot welding. The soldered batteries don’t show immediate damage but after repeated usage then do not seem to last very long. Only difference between the two methods of joining is heat. The heat does indeed cause battery damage. The spot welded batteries last far longer because the spot weld does not transfer very much heat into the battery. Over time concentrated heat joints just kill 18650 Li-ion batteries. Case closed.
Now lets see the heat localisation on high amp discharge with all three different methods of connection.......
hi maiky. will you please give us an idea about the mid drive kit? and maybe comparison with hub motors from your point of view.. i would really appreciated..
Micah it would be better to cycle the 2 type methods 10 times to see if any mAH are lost. For a better test its kind of half finished.
skipsteel .
@lqlq4 That's what skipsteel just described...
It is really hard to solder to the negative terminal, due to the size of it and it spreads the heat out the length of the terminal and that goes the length of the battery. I had too many break off and I had to open the pack up to fix it. Once I purchased a spot welder I have never had an issue again. Spot welding is the way to go.
Nice experiments that convey a lot more than some random statements like spot welding is good!
A further experiment would be to measure the capacitance of a couple of cells (record them) and then use both methods and see if the capacity of the cell changes.
Ok it heats up but what are the consequences? Does the capacity of the cell decrease? Could you do a before and after capacity test to see what's the difference ?
Thank you very much for doing this! I was wondering myself: I have read and watched different videos on this and the best way to see the truth is to experiment! :)
Wondering about the current capacity of tabbed cells with a single pair of welds, or even two pairs? The conductivity of soldered VS welded? With the FLIR, would be interested to see if a tab welded with a single pair of welds would heat up under a heavy current draw.
I already started doing some similar tests and will be posting the results soon.
EbikeSchool.com
companies have been spot welding batteries for decades without issue so it cant be a problem or they wouldnt do it
Use flux liquid on battery before applying solder and iron , 2. Put solder on tip just prior to contact with battery
I discovered by accident that covering the area you want to solder with a black Sharpie marker helps the solder wet out a bit better, it might be that the solvent in the pen cleans the area.
If you sanded the battery with some emery paper then used some good flux, the solder would definitely adhere much better and quicker.
But, spot welding is definitely the choice when connecting 18650's or any battery.
I really like your videos, but while soldering carries more risk, you are using a medium sized tip, with a not very big iron, and you didn't sand the contacts beforehand.
Using a bigger tip, a bigger more powerful soldering iron while using sanding the contact and spreading flux on it, I can easily solder within a max of 2 seconds after some practice on completely dead cells. You probably could do it in 1.5 seconds with much more practice.
Your method is basic and could use some refinement, especially as cells don't like excessive heat as you might know :D
NeutronPCXT - Flux?
Solder flux. To prevent oxidation and help the solder to stick.
@@neutronpcxt372 it doesnt matter what prep work you do the item you are soldering still has to get to the melting temp of the solder or you wont have a good joint and that goes for all forms of soldering not just electrical soldering
@@bjorn1583 Yes, but with a massive iron that has a large tip with a lot of surface area, the solder can liquefy extremely quickly, and stick extremely well.
On top of all of that.. He should have added solder to the iron tip each time. His tip is dry and crusty every time.
I am so glad there are youtubers who know the term "Wetting" when it comes to Solder. I've seen so many youtubers soldering and I nearly laugh or cry or vomit at how awful their idea of soldering really is.
Thank you for being educated in proper soldering terms and practices.
It Helps when you explain how you did it. Thanks
After watching your video, money is the only thing that is holding me back
There seems to be lots of different spot welders. The spot welder @ hft has top & bottom tips that meet @ the working material up to 3/16" thick
There are two main reasons why the manufacture uses a spot welder. First its the fastest/most efficient way to make a battery pack. Second is very high drain current produces heat that can melt the tin on the tab and diconnect the wire/nickel plate.
Any electronic devices with high current consumption or current path use mechanical contact and not soldered.
I think it's way more better with an oldschool soldering Gun than a soldering iron! Sanding is neccesary for soldering!
You have to rough up the surface with sandpaper and then apply some RA flux for a proper solder joint.
Cool video thx for sharing . I thinking Flux would of helped you think ? maybe light scuffing of the cell metal that is to be tinned?
Love the spot welding machine what metal strip was that you spot welded with ? Thx
you are right. But the spot also does a high temperature. If you look at the video at slow speed, you will see that the temperature repeatedly reaches 184 degrees Celsius.
Yes that was a good demo - and making your own eBike is a great project. I'd still prefer my www.flx.bike though. I'm using the cell welding for a different project - Thanks for the video.
A thermal sink while soldering might be a good idea. Ie, make contact with the surface near the solder point with a fairly massive piece of metal.
I think everyone knows that spot welding is better. The major concern is how soldering affects the capacity and at what temperature&second it will be dangerous
Spot welding is NOT better. Maybe a little safer? Yes, but deff not better. The spot welds are trash, you could never trust them on a critical project. They hold just enough. When using these cells for high current applications then the nickel strips just can't hold up compared to a heavy gauge wire that has been soldered directly. Yes, i know your comment is from 3 years ago but nothing has changed.
When soldering those kind of thing you want a soldering iron of atleas 100W and apply some flux paste on where you want to solder sins chrome or what there those terminal are made out of don't like solder sticking to it very well.
BTW what thermal camera is it and where did you buy it from?
Probably a Flir camera. You can get one for your smartphone for 250-300$.
NeutronPCXT doesnt look like the smartphone flir and the next step would also look bad and cost around 2000$ but this one looks good enough for what I need so I was just wondering
Flux paste helps dissapate heat. But I wait till it cools down before I do solder on it again.
I think its proven that soldering doesnt really hurt the cell if you do high heat for 4 or less seconds. My question would be how the voltage transfer is different between a spot welld and a solder joint. seems like the solder would be better. SPot welds seem to break off more often?
I have both books and they are excellent! This is an informative video, thank you!
It was informative and visual! Thanks!
very interesting, i was sort of trying to decide if i could get away with not having a spot welder... maybe reviews of spot welders would be helpful? i see them on amazon for ~150
Even if it’s not a perfect test (let say in real condition) set up you made your point and that’s what I like about your video. Keep it simple KIS.
You must be a teacher or have the talent for ... :-)
Is spot welding safe for your eyes? Do you look at it directly? Ordinary arc welding requires a full face shield for safety. Isn't this the same principle, just on a smaller scale?
Hi, would be good to see how hot it gets using the smaller soldering iron. Also, when you show the thermal image and it get's hot, how do you correlate that to potential damage. The heat may only be locally affecting the battery but may not hurt the perfomance later. Would be good to show some performance check.
We must know what is inside the battery cells (solid, liquid, chemistry, etc.) and think about their reaction when being heated on that temp. Personally, I believe applying that heat will shorten the lifetime of the battery cells, PCMIIW.
Maybe that's one of the reasons the manufacturers using spot welding instead of soldering?
Thank you for this insightful video.
I was wondering if adding a small computer fan would help the battery stay cool or is it not necessary
Clean where you want to soldier first then put some soldier pasta on it to help. Then the more power your soldering iron has the faster you can solder it and the less time the heat has to move down. They make tools to use when soldering,, one has a small steal brush to clean and ruff up where you soldier. This helps the heat move to the place you want to soldier.
Bottom line that solder melts at 188C. So it's above that. If soldering, you might use copper ribbon. Nickel has no advantage for solder and copper has less resistance.
The 60/40 solder melts at over 180C, and both the solder and the surface underneath must get at least that hot to get a good joint. So nobody should be surprised to see a very hot spot in the camera after removing the soldering tip. The important question is how much of that heat energy manages to move into the guts of the cell where the plastic seals and sensitive chemicals are, and the camera cannot show that. If you want to reduce the chance of internal damage, why not cool the cells in the refrigerator for some time before soldering?
One thing I would like to see tested is which cell joining method is more resistant to vibrations. I would like to see the solder-less method included in this test. That would be important for e-bike applications but not so much for power wall applications.
Could you make a video showing how hot the cell gets while it is being wrapped in heat shrink tubing? I think some people will be freaked out by the findings ;-).
One thing I don't understand is people using nickel strips when soldering cells. The strip is the way to go when spot welding, but if I was soldering I would use only copper wire. Nickel strip is not only expensive but it is a poor conductor of electricity compared to copper.
You had one job! And I could have added a bunch more since the thermal cam was up. Test #1 bridge the gap between the + & - h a cooler more efficient way when your phones case is compared to leaving all my electro bug GNG o
And those spot welders need crazy house fuses nobody has.
There are many available. Good ones for less than $100. I have a one-handed rechargable that I've used to make welds on about 200 cells. I have never had a spot weld fail. I never solder onto the battery. When welding leads, I solder them to the heavy nickel strip first and then spot weld to the battery.
Very interesting videos, yes I keep watching and learning. I sure your Book will make me learn a lot more.