A fantastic and informative demonstration that was in no way diminished by shaky hands. Thank you for sharing your skills with us. The tip on using the heat compensating soldering iron is great advice in itself.
Excellent video on soldering takes me back to my days in collage when I was 17 learning how to solder. I use a green or brown scouring pad to clean the excess oxidation on cells its not as abrasive. A trade trick get some blue tack and stick your wires on them and stick them to the bench. Its a cheep second or third hand as you will need them while soldering connectors. Hotglue does to keep your cells together. I also find if you get a good quality manufactured pcb the solder will not come off the board. To get the solder off without damaging the pcb mix the solder on the board with your lead/tin solder and use a solder sucker to remove the solder done by the manufacturing process. I would also recommend using pcb cleaner or isopropanol alcohol to clean the pcb before and after removing components. Makes a professional job. Get it from RS, CPC or you local electronics supplier.
Thank you for all of your videos and advice Bruce, the legacy many older people are leaving through youtube videos will hopefully live on for multiple generations and provide inspiration and education to many.
Just like proffesors on my college (the older they are the better they are) you make the best educational videos, talking about the basic details needed to understand the whole picture Thank you sir!
Genius.... learn every time when answering the bell Helps my mental health using your philosophy sense of humor is how I get by as well, and patience w/ my hands while I work.
This is very helpful, and I appreciate you doing the demo regardless of shaky hands. The amount of obsession over spot welders I'm every other video and discussion convinced me that lithium batteries are altogether incompatible with soldering.
This worked 100% for me Bruce I made 2x 2s packs for my petrol baja buggy and only used one pack my buggy runs for 3-5 hours every day for a week on one charge \m/ great idea
Once again, you've proven to be one of the best teachers in the hobby. Going to be putting together some packs out of 21700 cells for endurance flight. Molicel is producing cells with incredible current capabilities.
Thanks so much for the suggestion to scuff the ends of the new batteries! My wife has a 16-volt CHV1410L Black and Decker hand vacuum that's several years old and would only run for a minute or so on a full charge. I ordered new 18650 li-ion batteries to replace the originals, but when I tried to solder in the new batteries, the solder would cling to itself in a ball and didn't want to melt to the ends of the batteries. I watched this video, followed your suggestion to scuff the battery ends with sandpaper, and it worked like a charm! Now the hand vac is back up and running!
Please don't under estimate the importance of extracting the fumes when soldering. Iv been soldering the 18650 cells for years and iv developed a blood condition called LCH which is being treated with chemo.. not fun..
Damn, I hope you will do better and beat it. Thanks for the information. I was worried about this risk but I never know its actually as much dangerous as this case. Do you think its necesery to filter the fumes or just a normal fan is good enough?
@@robertzeman4301 Hi. Yes all good now thanks. Depends on how much soldering you do. If its a small room then id ensure that the fumes are sucked out. A shed of garage you can just open the door i guess. A small fan that blows fumes away from your head is probably a good idea. Sill not 100% sure as the resin is from a tree I believe so there's only the lead content to think about. More research needed. Sorry it took 3 years to reply. :)
@@araaraara12 Hi. Depends on how much you do. I was soldering all day. Think expelling air from the room using fan and ducting is all you need. Ventilation is the key.
I saw a video this year of someone who has soldered a ton of 18650s, he used fuse wire to solder them together, which I thought was a bloody genius idea, because if something goes wrong and wires get shorted out, the fuse wire just breaks.
I bought some fuse wire with the idea of using it in this way one day, the 5A is thinner than you might think at 0.22mm diameter, whilst the 15A is 0.52mm and the 30A 0.78mm.
Super informative video - just what I was looking for. Thanks very much for making this! Only thing is that I was so tense watching you solder so close to your hands without gloves on, haha.
Thanks for this. I am about to replace the 18650 in a cordless screwdriver. Also I've been looking for a good soldering tutorial. I'm looking forward to watching that now.
Whats the fun in soldering it when you could spend tones of time and effort trying to make a mini spot welder then giving up on the project all together later?
Thank you very much, Bruce. My wife got me forever (lol) radio/flashlight, which has a hand crank dynamo, a solar cell and a wall blister for recharging. I know the storage system will not last forever, so I opened it up and discovered a 18650 inside with soldered on wires. I was concerned about replacing it when it will no longer hold a charge, but, thanks to you, good sir, I am no longer concerned. I live dangerously and buy 10 to 12 battery lots with reverse polarity protection from China. I assume 1-3 of them will be bad, but the price is low enough to make that acceptable. If they work on first charge, they seem work very well so far and I am only using them in flashlights, so far.
Contrary to what Bruce said, 18650 Li-Ion cells (and all other cylindrical cells with the same chemistry) have pretty well the same voltage range as LiPo cells. You can use the same charger. Charge to 4.2V per cell using constant current followed by constant voltage. Never discharge below 3V per cell. Li-Ion may be a bit more forgiving than LiPo for discharge but not significantly so. For Lipo cells I would recommend not going below 3.3V per cell, but 3V is not so bad. Optimal storage voltage is also about the same for Li-Ion at 3.8 to 3.85V per cell, not the 3.46V that Bruce mentioned. There are many sources you can look up to confirm what I am saying. I suspect that Bruce may have been thinking about LiFe cells, which do have a significantly lower voltage range of 3.6 to 2.5 volts per cell.
If you look at the discharge curves for the 18650 cells you'll see that most of them rate the minimum cut-off voltage at about 2.5V... quite a bit lower than the safe minimum for Lipos.
Spotwelder was invented for mass productions and its has nothing to do with quality, its simply good enough to sell it. Repair shops and workshops with batteries seen many times a lot of cases when the spot from welding didnt survive the stress and peeled off. Soldering is much more better with higher quality and safety, but you have to learn how to do it and you can do mistakes. Btw you can also quickly tip the spot on the battery with the iron like a drummer. :)
I did this about a year ago I made A 2S pack with balance charger leads for my fatsharks They were higher Mah batteries then any lipo i could find for it . I even wired in a little voltage checker with the 4 led's like original fatshark batteries have.they are still working great haven't had any issues with the solder joints.
In the aerospace industry, we are concerned for all tin solder as it can cause a condition called tin-whiskers. The tin grows tin crystal structure hairs (whiskers) and can cause boards to fail due to shorting. NASA has updated requirements restricting all tin solder. It's best when alloyed with lead. Just some fun trivia I am sharing from my job before I retired.
Do these Li-ion battery need to be balance during charging? What kind of charger would you use? I trying to figure out what's the safest way to charge such a battery pack.
What temperature is your iron at? As important as speed is with Li-ion, I think many fellow viewers can relate to me: even with my iron on max, it doesn't go that fast.
I just bought these batteries for an rc car for longer run time but the positive end was too flat to meet connection this video explained exactly what needs to be done.
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.
You should look into hyperbaric chamber therapy. It forces oxygen through your skin and directly into cells, helps with so many things including the shakes
@@RCModelReviews True, the average voltage is lower, because of the lower bottom range. Need some advanced calculus to calculate the watt hours in a discharge curve, rather than just looking at the MAH. This is why some people are confused as to their testing results, although they still stack up well against lipos in relatively low discharge rate applications. I prefer the NCR18650GA cells myself, if you can tolerate only 10 amps per cell max continuous discharge rate. They have 3500mah compared to the LGH2 cell's 3000mah, but the LG cells put out double the amps on demand, and that's more suitable for most people who don't know how to use a throttle, or think that airplanes are helicopters.
@@markhinchcliffe5803 I'm fine, my friend. Thanks! What about you? 😊 Well, I know they're better for the 18650 cells... I even know how to make one... But I still don't have one. 😕 Why?
Im looking at buying 1 for Christmas, but i know there are some that dont really do the job,i would like 1 that ticks all the boxes at a reasonable cost as well. Oh im great to,thanks for asking
@@markhinchcliffe5803 Hmmm... I see... That's a difficult subject, really. 😕 What I would do is to look for reviews on RU-vid. Then I would look for complaints on Google. You know? There's no much other way. 😕
Sunkko 787+ I did exactly what you just said,this unit seems to get a good wrap and has a good cost as well,there are a lot of bad units out there as well,they also mention to put it on a larger circuit breaker.
I use a soldering acid and wash it off after you have laid the solder down. That looks good.. But I will probably stay with the soldering acid.. I have used it for many years on many different applications.. But yours is a much safer way to do it.. especially if folks have not used acid before.. Now I may have to go try it.. I am a bit older myself (68 next may) and it would be a better way if I didn't have the acid in my tight little bench area.. so thanks for the "update"...
Thanks again Bruce for some super useful information. I hadn't looked into it and didn't realise that Li-Ion batteries were a higher energy density. I wonder if a boost converter is worth installing to lift the voltage?
ahh the key to this is to scratch the surface of the battery where your applying solder. i been trying without scratching it and it just wouldnt stick. flux didnt do jack either. i think it must be some sort of anodizing on the terminal.
Its not the top you have to worry about as much as the bottom. The top is a raised thin piece on most cells. Also use 99% alcohol or acetone after you sand..
Did that for my FPV goggles power. 6:55... A suggestion... Find something that you can fit the Battery into to hold it steady while soldering. Bruce... the hole in the Solder Roll itself comes to mind ;-). You could also drill a ~19mm/3/4" hole into some scrap 2 x 4 lumber to hold them steady. 10:18... Just saw that you found the battery holder trick... LOL
Yes, Use a seriously Hot Iron. As soon as the solder flows, GET Off the cell. Limit the solder to just enough to wet the surface of the cell. Pre Tin the Wire and Re-flow connecting to the cell. Job Done ! Zero damage to the cell using this method. Use regular 60/40 solder.
Thanks for the confidence that it'll be OK - I've been a hobbyist off and on for decades but always been wary of soldering Lithium chemistry cells thanks to scary youtube vids, but yep I can keep it quick I'm sure, and your tip about not fluxing the cell pad is helpful
hey Bruce! Just to be clear there isn't much difference between "lithium polymer" batteries and the "lithium ion" cells. Both are the same, but there are different chemistries which DO have some small differences (IMR, INR, etc.) The hobby has come to calling all flat pouch cells "LiPos"
a d following that, the reason high power density pouch cells have a higher cutoff voltage is due to the higher discharge rate and safety margins. Cells have very low capacity when almost fully depleted. (voltage drops off fast!)
Some of those chemistries are going to radically change life particularly transport. The recent open sourced bench mark battery design from Tesla's Dr Dahn will allow many more cycles and be more temperature tolerant. Other electrolyte chemistries and electrode construction will allow quicker and higher voltage charging and increased energy density. Watch out for Tesla's Battery Day Q1 2020 presentation for the Dahn dual chemistry electrolyte and Maxwell dry process cathode LiIon 2170 cells. jes.ecsdl.org/content/166/13/A3031.full
I find 330°C to 345°C works very well (the lower for SMD, the higher for throughhole). But you should have a decent soldering station/iron that is reacting very quickly and has enough power behind it to keep that temperature. With higher temperatures than that pads often start to oxidize before you can even add enough solder to cover everything.
We have a bunch of these irons at work. I have my iron at 380c all 8h of the day. Wouldn't go below 350 (even for tiny wires) Wouldn't go above 420 unless it's for the occasional blast as it oxidises the tip quickly
thanks guys, recently got myself a new iron. and wanted a idea on good temps to run on it. hope its a half decent iron. www.jaycar.com.au/soldering-station-60w-led-esd-safe/p/TS1640
A bit of flux such as Kester 186 will also help. Also Samsung 35Es are probably the best 18650 cells for RC transmitters right now. They have a slightly higher cutoff voltage of 2.65v rather than 2.5v and because the capacity is rated by 4.2v to cutoff you get a bit more useful runtime out of them. The flip side is that they have a lower max amp rating than Sanyo and LG 3500mah cells and a bit worse capacity at higher amps but for a low draw application like an RC transmitter this doesn't matter.
i was thinking you should make something like a set up with a weather balloon into space. And then you FPV back down in a glider or something like that.
Hope you're going ok Bruce. I don't watch your vids much anymore but I always really enjoyed watching in years past. I learned a lot from you. Do you have any idea what happened with the Spoktra50 channel? Those guys cracked me up!
Have you tried soldering on the nickle ribbon thats meant for spot welders? Once I moved to that I found packs were so much easier to make, especially stuff like 4s2p or similar packs
In terms of the voltage dropping too much for the flight controllers when the li ion goes down to 2.5v a cell, couldn’t you just use a higher cell count but of a smaller cell to save weight? Like a 18350?
Great tip Bruce, I personally use a high wattage non temp adjustable iron and as you say, for a very small amount of time...I think the main distinction between Lipo's and Li-ion's is that the available current is limited in Li-ion's compared to Lipo's eg. 10 C compared to say 50 C to 100 C for Lipo's.
The often used distinction between Li-ion and Li-polymer has nothing to do with chemistry (it is used wrongly. Pouch and cylindrical cells are just different form factors. There are different chemistries within that class, but again that doesn't have anthing to do with the form factor. The main difference is that the different form factors are built for different applications (high current vs. high energy density). They are *all* Li-ion batteries. The formfactors can have different chemistry, but so can cylindrical cells between them and pouch cells between them. The form factor is not what dictates the chemistry, what the manufacturer puts in them is. You can have the same chemistry in either form factor. Have you ever seen something like IMR, INR, ICR, IFR, LMO, NMC, NCA, NCO, LCO or LFP written on cylindrical cells or in their datasheet? Those signify different chemistries. Pouch cells use the same, although they mostly use the Lithium-cobalt-oxide chemistry (ICR/LCO). Real Li-polymer batteries are still a research topic. Those batteries are *still Li-ion batteries* , but their electrolyte is a solid polymer. Current batteries have a solvent based electrolyte and the only polymer in them is the separating plastic foil in the battery. It is that solvent based electrolyte burning btw. that you see in battery fires. Lithium has nothing to do with those fires.
@superdau Thank you for such clarity on the topic, however I did not assert that the distinction was down to chemistry. All of this information I already know, being that I have a materials science background and I feel assumptions may have been drawn here. I was merely stating in laymans terms, that the different types of cells, have very different discharge characteristics. Furthermore I do appreciate this info is of a good understanding and valuable to new entrants to the hobby and our modern world in general.
Sorry for the dumb question: but if that's so easy, why do they spot wedded? Is there more resistance (lost heat) on these solder or the wire (compare to a large flat metal tap)? Or is it just about safety?
short answer is carefully.....i use a bit of wet cloth to wrap around the battery while soldering....also use sandpaper on contacts just before applying flux and 400 degree for the iron.
A Tiny Drop Of Water Diluted Real Pine Tree Resin In A Dropper Bottle Works Best On Soldering Any Electronics! Won't Hurt Any Circuits & Is Actually A Great Protective Coating Against Corrosions!
very informative as always - but would just like to point out that care needs to be taken not to damage the plastic wraps on these batteries and if they do get damaged they need to be re-wrapped
Use your biggest soldering tip ie the most mass, crank the temp and be fast. May also want to practice on dead cells first.. Quick refresher for the experienced, a good idea for the noobs 🤞👀
Seems very simple to do Bruce thankyou for posting it. May i ask, you mentioned the spot welders available on sites can you reccomend which ones are a good buy and will do the job properly,or if anyone else knows could you provide a link or model number please.
@@leephcom i looked at the links you provided,a kit version,not self contained,power supplys not supplied,programming needed,no welder handle,i suppose if your doing it for a living they are a must but id rather a assembled unit just for personal use. Buy thanks for the reply,if not Sunkko what else would you reccomend.
Don't solder lipo cells! One of the tabs is made of aluminium, which can only be soldered with a special very corrosive flux that needs very high temperature to work. The heat sets off a chemical reaction in the cell, and a couple of days later most of your cells are inflated like balloons and no longer work. If you cannot spot-weld the tabs, make some small holes in them and bolt them with small nuts, bolts and washers. Also apply a product such as Noalox to the tabs when you bolt them, to maintain a low-resistance joint.
I already did this with Samsung cells of Banggood. They are pretty good. Used 2 of them with a power level print with LEDs and a button to check for my skyzone goggles 👍
