I use adhesive copper tape (5mm wide) ... You can solder the cable to it and than wrap it around a magnet few times. This way the cable is secured perfectly on the magnet and the copper tape makes perfect contacts. No magnets will be harmed during this process ;)
The other issue is that your solder connection is to the thin chrome plating. Depending upon how well that plating is bonded to the actual magnet you may see seperation issues.
Thank you for the video, you confirmed my idea so I don't need to test it! Just a note for everybody: neodymium magnets can loose its magnetism because of excess heat (there are differences how much heat a neodymium magnet can handle) so don't solder them long time. In this video the heat shock is absolutely acceptable. Edit - Note2: Maybe the solder only diffuse inside the magnet's coating which can be weak. It can be tested by a thick wire soldered and then trying out the strenght of the soldering. I will test it sooner or later and share the result.
Stick the magnet you are soldering to another magnet preferably a larger one. The heat causes the particles to speed up and misalign, if they are stuck to another magnet it will help keep orientation.
Might have been better to solder to steel washers or something, you could even solder to washers that are larger than the magnets to allow for the wire, or maybe a piece of steel food can, I would probably buy some battery holders though
a small bit of copper foil folded around the magnet, perhaps with a tiny bit of epoxy or super glue for good measure would probably be best. The coated magnet makes for a lousy connector because of its high resistance.
Very Cool Video Julian. I remember one day I was in my Workshop years ago now but I decided to heat up a magnet with a blowtorch for some reason that I can't remember now but It did lose it's magnetism. Very Cool Science...! Keep up the great work. Nick.
One of the other commenters suggested soldering to a washer. I suggest using a solder lug instead. Then either stick the magnet to it or sandwich it between two magnets. That will also solve the problem of the wire getting in the way (since it will be offset to the side).
A nice way to avoid the heat issue would be firstly soldering the wires to iron disks which will then be attached to the magnets. The proper way is spot welding, as it only heats up the actual weld, leaving the magnet cold.
That's what I was thinking! Any small piece of steel would be perfect; maybe a washer. Solder the wire to that and sandwich it between the neodymiums .........
I cut a small rectangle of the 200 µm iron based wrapping of a 9V prismatic battery. It is strongly attracted by the neodymium magnet and attached by crimpsing to the copper wire makes a beautiful battery connector. No need to solder and it is a nice upgrading of dead 9V batteries.
With the wire you have shift the magnetic flux direction,bit like magnets around aluminium tubing which causes a sort of vortex effect through the tube even though it's non ferrous.
Magnetic viewing film will probably give a clearer image than iron filings, given the small size of the magnet. Build a Gauss meter, too :) Maplin used to sell magnets terminated in tinned solid core wires which were crimped on with tiny metal cups. Don't think they do them anymore, at least I can't find them on their site :(
I use a Sainsburys stainless steel scouring ball in one of those blue flake fishfood tubs for scraping my iron. Works great, couple of dabs each time I pick it up or finish soldering, better than any sponge.
I use a stainless steel pan scourer to clean my iron tip as well as a wet sponge. The scourer sits in a small pot next to my iron. They are very cheap and don't rust. A gentle wipe cleans off the black flux residue.
It appears that the battery has a magnetic field. The soldered magnet has the reversed polarity so it is repelled and pushes off to one side. Flip the magnet over to fix the problem. Love your videos!
If anyone see's this and wants to try doing it. Stick the magnets to each other when soldering it will help maintain a north and south pole orientation. The reason heat destroys magnets is the particles get excited and change orientation into a random pattern a second magnetic field can help stop this.
Regarding the soldering sponge. The cheap stainless steel kitchen scourers placed inside a glass ramekin (the type you get with GU desserts) seem to work quite well as a cheap alternative to the brass ones. The problem with a wet sponge is that it sucks the heat out of the iron which can slow down your soldering.
did you try turning over the magnet with the wire to see if it would stick better. Looks like the battery terminals have little magnetic by the way the magnet is behaving. Just a thought.
One other thing, you can remagnetise those neodymium magnets. Use a massive coil around the magnet and attach a high current supply like a welding transformer or a car battery. Im not sure about the forces though, the magnet might just end up penetrating your windows.
You could put some iron dust on a transparent surface (printable plastic, food packaging,...) and the magnet on the other side, the shape of the iron would easily visualize the magnetic effect... I always keep that powder when I dremel metallic things...
Thank you for the video. This is encouraging, I'm planning to try the same thing for a battery pack I'm building. If it works it will be a big help for my application.
Holts Gum Gun is used for repairing exhaust pipes on cars and can resist 450 drg C. I do not know if its conductive. Perhaps it could also be used for mounting power LED-s to metal flanges.
Interesting to see how easy it was. The magnet is a "sandwich" of neodymium powder which is cast like a pill. (search How SuperMagnets are made) and covered in a bright metal envelope ... If they get damp or damaged you can see the bright metal will just peel off like foil and you're left with a dull grey compressed dust that will crumble away. Those thin magnets have a shallow field doesn't take much to disrupt it. I suspect that the "shift" in magnetism is due to a combination of heat and the Lenz effect ... lots of content about it on YT too - just search "copper and magnets". As a "dirty" fix, well worth considering - I usually force part of a straightened paperclip under the insulation into the body of the wire, wrap the pc tail round the end of a screwdriver to make a flat "plate" and pop a magnet over that. Not a perfect contact, but good enough.
It seems it would take a lot more heat to do that to the magnet. I was using them for brazing, and I got the magnet very hot and it didn’t lose its magnetism if that’s a word.
you can get plastic sheets that show the magnets waves to see if the magnet was affected, they use magnets with multiple poles and demagnetised parts now in new machines and locks, super magnets... amazing things... geek squad i thib has a vid on it.
another alternative: spot weld a short length of nickel strip to the magnet and solder a wire onto that. Yes, I tried it and it welds fine although it took 50j of power on my KWeld spot welder. Note - check the resistance of the connection because I usually see around 200 mOhm ( 0.2 Ohms) which might be significant for some applications. Magnetism totally unaffected.
If the current is low enough, you might want to try cold solder - it's a water--based glue which is pretty much saturated with very finely powdered carbon, so it looks black as ink.
Have to get one of those toys we used to get when we were kids. I think they were called "Fuzzy Face" with a cartoon like mans face and iron filings and a magnet so you could give him a beard or mustache using the magnetic wand. Iron Filings should show you the magnetic field if you put the magnet under the cardboard of that toy by standing the iron filings on their bottoms.
Good video thanks. Was thinking of doing magnets for a ebike battery. Not sure it will work but I like the idea of being able to remove batteries and not have the welded together. Obviously will look at the comments as they solve the issue ou have had with the magnet. Many thanks.
Another option might be conductive adhesive. You can buy conductive epoxy, or get experimental by adding graphite powder to regular epoxy and see what kind of results you can achieve.
Heh, opened my subscription feed after having finished soldering wires to magnets barely 10min earlier... I used fairly similar magnets, cheap 8mm ones from fleabay that weren't that strong to begin with, but went for the 'big glob of solder in the middle' tactic instead and sadly I did notice difference in magnetisation so have to add a second magnet.
try to use some metal tabs that you solder the wire to and then use the magnet between the metal tab and the battery terminal. Not as elegant, but it would avoid changing the magnetic properties of the magnets.
question, why are you guys making 18650 chargers when they are very very cheap? I mean, just buy a power bank shell from ebay or ali and usa that to charge the 18650. I have a 5 cell one that I can open and pop some batteries in there.
The meaning of DIY is learning to do it yourself, and in the process you'll learn a lot which later can be applied to something that isn't dirt cheap. I recently refurbed a 36v Hammer Drill which were going in the bin. Replaced brushes and batteries cost me 30 bucks on fleabay, and now I have a 600 dollar cordless SDS hammer drill.
OrbitalSP2 the cheap power bank boxes charge and discharge all the cells in parallel. I dont think thats ideal for cells of different capacities or discharge states, I'd rather have a separate charging circuit for each cell. but mostly Im doing it cos I like messing around with electric stuff.
I used a bunch of those boards to charge up loads of 18650's ready for testing for LiIon battery packs. Great little circuit. Using cheap battery holders from china is a LOT easier though. I had about 300 batteries to get through and so I set up nearly 20 of these.
I think most of these magnets are nickel and/or chrome plated. Nickel plating will take solder really easily., but the plating often comes off quite easily in my experience.
Interesting. Wasn't aware of the issue - the magnets I've soldered to seem to hold on ok. Could a Hall effect sensor be used to test the magnetification (that's surely a word) of heated and unheated magnets?
battery > coppershim > magnet singlesided..... or battery > shim > magnet > shim > battery on doublesided connection..... shim is soldererd to cable and magnet glued on top... so the magnet is not used as connector... the shim is... so no, the glue dont hinder it to make connection.... unless you splash around with the glue?
I think the copper shim is meant as the conductor between the wire and battery. The magnet would provide some 'sticking' force keeping it together. As the copper cannot provide that. A copper sheet would be better though, to not reduce the force due to extended distance.
True.... Was just the first ting that popped in to my head to bypass the need for soldering onto the magnet.... There are plenty of solutions and mine was just a brainfart then and there..... youknow take what you got and rig somting upp....
There's another video on RUclips that shows that when you heat a magnet It crosses the electromagnetic Field direction so try doing it on top of a bigger magnet To re-align
If you have some fine iron dust, you could compare the magnetic fields of a soldered magnet and an untouched one. Just place the magnets under some paper and compare. I've never used that magnetic film. Never heard of it until I read the comments. Always used paper and a sprinkle of iron dust. Looking forward to the next video on the subject.
Strange to see the Curie effect is irreversible. My Weller solder tip works with this effect, but maybe it's a special alloy. Why not use two (larger) metal rings to solder the wire on and place magnets on both sides. Win-Win.
Now you will have to solder the exact oposite side of the magnet with another wire an then connect the end of the wires together so you will get back the balanced magnetic field as before and the magnet will stick at the center this time ( if not do it in 4 places or 8 places in both sides ) :)
Normal magnets loose their magnetism when a physical shock occurs - a problem that neodymium magnets do not have. The way neodymium magnets loose their magnetism is heat, and theres specific temperatures given online.
when soldering to the magnet use as low a temperature as possible. With how fast the solder just wicked onto the magnet I can guess your iron is way too hot. I would suggest having as much contact area between the magnet and the piece of metal as possible, using some flux on the magnet while having solder already on the iron. that way you have the fastest time possible to take your iron off of the magnet before you mess with the field too much. If you have a temperature controlled iron somewhere that would help a bunch too. (I know it helps me out every day)
Not too low of a temp, but with how fast and how far the solder wicked up the temp was def too high. gotta find a balance for the material. Thermal conductivity, and thermal mass of the magnet; thermal conductivity, temp, and thermal mass of the iron. just a few factors to help decide what temp to use. But you are correct, too low and it takes too long. There are many different ways to solder a wire onto a magnet and It may be difficult to get it down. I wonder how spot welding onto the magnet affects the field...
n 65 neo, or higher. copper plate 1/4, use silicon wire #22. Clean magnet with 90% ISO-prop alcohol. I also used two pieces of aluminum # 10 gauge sheet metal clamped, as a heat sink. Worked good for me. I have been using them and TP 4056 to charge lithium cells for a while. A little flux pen helps too. Just some ideas.
I think a small spot welder that is used for welding liion batteries together might be able to do the job better, those should weld without heating the magnet too much
Dear Julian, The Curie point of the cheaper NdFeB magnets is ~ 80'C. You did indeed demagnetize a portion of your magnet by soldering the terminal to it. What many people don't know about a 1/2/5 eurocent coin is that it is made of excellent magnetic iron (not copper). You can solder a wire to such a coin, and stick the magnet to it after it cools down, for best results. Oh, but wait.. Brexit :p
If you want to do this and not loose the power of the magnet. Take the magnet you want to solder and place it on a second magnet that is bigger. 2 or 3 times the size. Then you can do what you just did without loosing any of the magnetic strength.
What if you use a lower wattage iron? 60W seems a bit high for what I presume is leaded solder, especially for soldering to a magnet. In my personal experience with soldering irons, even a 45W iron gets quite hot.
Heating magnets results in a loss of magnetism strength, In any case, roughing up the surface would help a lot followed by alcohol wipe prior to soldering
I won't say I told you so, but... :P I honestly thought it'd be a lot worse though. Maybe pre-freezing the magnet and sticking it onto a heatsink would help prevent and slow down transfer between the entropies while soldering? It's probably easier to just take a ring connector, crimp with cable, and sandwich it between two magnets. Easy and basically no mess with glue or solder. In addition you'll get a flat surface for the battery and the magnet ;)
I don't suppose it's as simple as you getting the magnet's north and south poles mixed up? The kind of "stay away from the center, go toward the edge" behavior of the magnet I've seen before when a magnet is flipped upside down.
Charging the cells in series seems to cost more than in parallel. I've seen so many videos on the TP4046 each charging a single cell and all powered on the same supply in parallel. What is the end goal here?
Would there be any resistance in the magnets? I want to have a battery connected to magnets so i can change out for different LEDs but i don't know if i would have to fit a different size resistor because of the magnets
Hey remember you're putting metal onto it which will change the magnetic field of the magnet. Doesn't take much to do a lot. Also you might want to just use a conductive epoxy instead of solder. It's a bit more expensive but you have 0 drawback with it and no chance to permanently alter the magnet
No the heat is causing the particles inside the magnet to excite and change into random orientations he needs to stick it to another magnet when soldering to try and maintain the north south pole on the magnet. The solder itself doesn't effect the magnet because it's tin and lead or silver and is not magnetic.
Better to spot weld a nickel strip to the magnet and then solder the wire to the strip. Otherwise a thin brass strip folded into a loop with the magnet held in there with epoxy or superglue.
Have you tried flipping the magnet over to see if that makes a difference. I wonder if you magnetized the battery terminal and it was opposing the magnet?
I don't know much about heat's effect on magnets. But neodymium magnets have 4 poles, unlike the regular magnets which have 2. Perhaps by adding the conductive solder and wire has changed the shape of the overall combo, and therefore the pattern of that complex balance between poles... Shifted it sideways, maybe?
When I say "look it up", I mean somewhere other than RUclips! Anyway, here is a link: physics.stackexchange.com/questions/12283/if-you-place-a-spring-on-a-neodymium-hard-drive-magnet-it-appears-to-vibrate-in
Hence why I said last time: Don't heat magnets. The area you heated has now become demagnetised. You can test it with a clear jar with some iron filings. Place the magnet on the jar and you should be able to see a pattern where the dead zone is on the magnet. Just don't heat magnets, it's a bad idea...
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The simplest solution would be to just solder onto a metal washer, then stick a magnet on the washer. It'll hold just as well as a magnet on its own.
I was wondering the same thing. why take the trouble of soldering magnets when you can stick a small plate on which you solder the wire in between.
thanks for the suggestion !
you would have to also glue the washer to the magnet to keep secure. I would use an E6000 type of glue.
But won't glue act as an electric isolation between magnet and washer?
@Arnold Rimmer I think you replied to the wrong user, I said the same thing 😛
I use adhesive copper tape (5mm wide) ... You can solder the cable to it and than wrap it around a magnet few times. This way the cable is secured perfectly on the magnet and the copper tape makes perfect contacts. No magnets will be harmed during this process ;)
_"A bit messy on the tip, i think i need to wet my sponge."_
-*Julian Ilett*
The other issue is that your solder connection is to the thin chrome plating. Depending upon how well that plating is bonded to the actual magnet you may see seperation issues.
Lets just say I have had a different experience with the cheap eBay ones I buy!
Thank you for the video, you confirmed my idea so I don't need to test it!
Just a note for everybody: neodymium magnets can loose its magnetism because of excess heat (there are differences how much heat a neodymium magnet can handle) so don't solder them long time. In this video the heat shock is absolutely acceptable.
Edit - Note2: Maybe the solder only diffuse inside the magnet's coating which can be weak. It can be tested by a thick wire soldered and then trying out the strenght of the soldering. I will test it sooner or later and share the result.
Stick the magnet you are soldering to another magnet preferably a larger one. The heat causes the particles to speed up and misalign, if they are stuck to another magnet it will help keep orientation.
Might have been better to solder to steel washers or something, you could even solder to washers that are larger than the magnets to allow for the wire, or maybe a piece of steel food can,
I would probably buy some battery holders though
Heck, you could even grind a groove into the washer and have the whole assembly be flush. Great idea!
a small bit of copper foil folded around the magnet, perhaps with a tiny bit of epoxy or super glue for good measure would probably be best. The coated magnet makes for a lousy connector because of its high resistance.
I was thinking of something similar. Solder to a tag, therefore the wire is offset, and wont interfere with alignment of the contact magnets.
Sparky Projects bloody hell of course, thank you 👍
Very Cool Video Julian. I remember one day I was in my Workshop years ago now but I decided to heat up a magnet with a blowtorch for some reason that I can't remember now but It did lose it's magnetism. Very Cool Science...! Keep up the great work. Nick.
some flux on magnet will make proces even quicker so less damage
One of the other commenters suggested soldering to a washer. I suggest using a solder lug instead. Then either stick the magnet to it or sandwich it between two magnets. That will also solve the problem of the wire getting in the way (since it will be offset to the side).
obviously it will not connect to positive terminal you need a red wire !
You have some wicked soldering skills as if you had a 3rd hand.
A nice way to avoid the heat issue would be firstly soldering the wires to iron disks which will then be attached to the magnets.
The proper way is spot welding, as it only heats up the actual weld, leaving the magnet cold.
Surely soldering to a piece of metal and then having the magnet stick to the metal is a far better way to do it.
That's what I was thinking! Any small piece of steel would be perfect; maybe a washer. Solder the wire to that and sandwich it between the neodymiums .........
I cut a small rectangle of the 200 µm iron based wrapping of a 9V prismatic battery. It is strongly attracted by the neodymium magnet and attached by crimpsing to the copper wire makes a beautiful battery connector. No need to solder and it is a nice upgrading of dead 9V batteries.
With the wire you have shift the magnetic flux direction,bit like magnets around aluminium tubing which causes a sort of vortex effect through the tube even though it's non ferrous.
For a Magnetic visualizer go back to grade school. Put a card on each magnet, heated vs non heated, and sprinkle iron fillings on it.
I'll have to get some iron filings :)
have a grinder? maybe a dremel attachment. No need for laboratory grade iron filings.
+Julian Ilett lol just go to your bench where you keep your grinder and swipe a magnet over the floor
Put the magnet in a plastic bag first. It makes it easier to remove all the filings and dust afterwards.
Magnetic viewing film will probably give a clearer image than iron filings, given the small size of the magnet.
Build a Gauss meter, too :)
Maplin used to sell magnets terminated in tinned solid core wires which were crimped on with tiny metal cups. Don't think they do them anymore, at least I can't find them on their site :(
I use a Sainsburys stainless steel scouring ball in one of those blue flake fishfood tubs for scraping my iron. Works great, couple of dabs each time I pick it up or finish soldering, better than any sponge.
I use a stainless steel pan scourer to clean my iron tip as well as a wet sponge. The scourer sits in a small pot next to my iron. They are very cheap and don't rust. A gentle wipe cleans off the black flux residue.
Neodymium magnets are plated, so you are only soldering to the plating, which can flake off. They will demagnetise at typical soldering temps.
It appears that the battery has a magnetic field. The soldered magnet has the reversed polarity so it is repelled and pushes off to one side. Flip the magnet over to fix the problem.
Love your videos!
If anyone see's this and wants to try doing it. Stick the magnets to each other when soldering it will help maintain a north and south pole orientation. The reason heat destroys magnets is the particles get excited and change orientation into a random pattern a second magnetic field can help stop this.
If you get one of the Hakko wire-type tip cleaners instead of the sponge, you will never ever want to go back.
magnet visualizer, iron filings when I was a kid in school
Regarding the soldering sponge. The cheap stainless steel kitchen scourers placed inside a glass ramekin (the type you get with GU desserts) seem to work quite well as a cheap alternative to the brass ones. The problem with a wet sponge is that it sucks the heat out of the iron which can slow down your soldering.
did you try turning over the magnet with the wire to see if it would stick better. Looks like the battery terminals have little magnetic by the way the magnet is behaving. Just a thought.
You could try putting the magnet into a widened crimp connector to use the crimp as the conductor without the magnet in the path
I was waiting for you to "blob" another spare magnet to see if it actually changed it.
One other thing,
you can remagnetise those neodymium magnets. Use a massive coil around the magnet and attach a high current supply like a welding transformer or a car battery. Im not sure about the forces though, the magnet might just end up penetrating your windows.
You could put some iron dust on a transparent surface (printable plastic, food packaging,...) and the magnet on the other side, the shape of the iron would easily visualize the magnetic effect... I always keep that powder when I dremel metallic things...
Lithium cell "Ultra Fire"
GG
Thank you for the video. This is encouraging, I'm planning to try the same thing for a battery pack I'm building. If it works it will be a big help for my application.
Holts Gum Gun is used for repairing exhaust pipes on cars and can resist 450 drg C. I do not know if its conductive. Perhaps it could also be used for mounting power LED-s to metal flanges.
I wish Neodynium magnets were more durable, they're extremely brittle. That said I just soldered 2 of mine with no side effects.
Interesting to see how easy it was. The magnet is a "sandwich" of neodymium powder which is cast like a pill. (search How SuperMagnets are made) and covered in a bright metal envelope ... If they get damp or damaged you can see the bright metal will just peel off like foil and you're left with a dull grey compressed dust that will crumble away.
Those thin magnets have a shallow field doesn't take much to disrupt it.
I suspect that the "shift" in magnetism is due to a combination of heat and the Lenz effect ... lots of content about it on YT too - just search "copper and magnets".
As a "dirty" fix, well worth considering - I usually force part of a straightened paperclip under the insulation into the body of the wire, wrap the pc tail round the end of a screwdriver to make a flat "plate" and pop a magnet over that. Not a perfect contact, but good enough.
It seems it would take a lot more heat to do that to the magnet. I was using them for brazing, and I got the magnet very hot and it didn’t lose its magnetism if that’s a word.
you can get plastic sheets that show the magnets waves to see if the magnet was affected, they use magnets with multiple poles and demagnetised parts now in new machines and locks, super magnets... amazing things... geek squad i thib has a vid on it.
another alternative: spot weld a short length of nickel strip to the magnet and solder a wire onto that. Yes, I tried it and it welds fine although it took 50j of power on my KWeld spot welder. Note - check the resistance of the connection because I usually see around 200 mOhm ( 0.2 Ohms) which might be significant for some applications. Magnetism totally unaffected.
If the current is low enough, you might want to try cold solder - it's a water--based glue which is pretty much saturated with very finely powdered carbon, so it looks black as ink.
Have to get one of those toys we used to get when we were kids. I think they were called "Fuzzy Face" with a cartoon like mans face and iron filings and a magnet so you could give him a beard or mustache using the magnetic wand. Iron Filings should show you the magnetic field if you put the magnet under the cardboard of that toy by standing the iron filings on their bottoms.
Good video thanks. Was thinking of doing magnets for a ebike battery. Not sure it will work but I like the idea of being able to remove batteries and not have the welded together. Obviously will look at the comments as they solve the issue ou have had with the magnet. Many thanks.
Another option might be conductive adhesive. You can buy conductive epoxy, or get experimental by adding graphite powder to regular epoxy and see what kind of results you can achieve.
Heh, opened my subscription feed after having finished soldering wires to magnets barely 10min earlier... I used fairly similar magnets, cheap 8mm ones from fleabay that weren't that strong to begin with, but went for the 'big glob of solder in the middle' tactic instead and sadly I did notice difference in magnetisation so have to add a second magnet.
try to use some metal tabs that you solder the wire to and then use the magnet between the metal tab and the battery terminal. Not as elegant, but it would avoid changing the magnetic properties of the magnets.
Im going to make a 18650 charger too, Im just waiting for some battery holders to arrive. Itll be interesting to see what you come up with.
question, why are you guys making 18650 chargers when they are very very cheap? I mean, just buy a power bank shell from ebay or ali and usa that to charge the 18650. I have a 5 cell one that I can open and pop some batteries in there.
The meaning of DIY is learning to do it yourself, and in the process you'll learn a lot which later can be applied to something that isn't dirt cheap. I recently refurbed a 36v Hammer Drill which were going in the bin. Replaced brushes and batteries cost me 30 bucks on fleabay, and now I have a 600 dollar cordless SDS hammer drill.
OrbitalSP2
the cheap power bank boxes charge and discharge all the cells in parallel. I dont think thats ideal for cells of different capacities or discharge states, I'd rather have a separate charging circuit for each cell. but mostly Im doing it cos I like messing around with electric stuff.
I undestand, I also like messing with electronics. Maybe you were just trying to charge them, but that is not the case :)
OrbitalSP2 Yeah, if you just want to charge them it's pretty far fetched.
I used a bunch of those boards to charge up loads of 18650's ready for testing for LiIon battery packs. Great little circuit. Using cheap battery holders from china is a LOT easier though. I had about 300 batteries to get through and so I set up nearly 20 of these.
for a brass cleaner thing, I couldn't find one in the shop so I bought a steal pan scrubber, works just as well also what solder do you use
I think most of these magnets are nickel and/or chrome plated. Nickel plating will take solder really easily., but the plating often comes off quite easily in my experience.
Something to note: the curie point for cheap neodymium magnets might be as low as 80 degrees celsius.
Interesting. Wasn't aware of the issue - the magnets I've soldered to seem to hold on ok. Could a Hall effect sensor be used to test the magnetification (that's surely a word) of heated and unheated magnets?
Solder wire to thin copper shim... superglue magnet ontop... and i'm not your uncle :)
Wouldn't the super glue act as an insulator?
battery > coppershim > magnet singlesided..... or battery > shim > magnet > shim > battery on doublesided connection..... shim is soldererd to cable and magnet glued on top... so the magnet is not used as connector... the shim is... so no, the glue dont hinder it to make connection.... unless you splash around with the glue?
I think the copper shim is meant as the conductor between the wire and battery. The magnet would provide some 'sticking' force keeping it together. As the copper cannot provide that. A copper sheet would be better though, to not reduce the force due to extended distance.
True.... Was just the first ting that popped in to my head to bypass the need for soldering onto the magnet.... There are plenty of solutions and mine was just a brainfart then and there..... youknow take what you got and rig somting upp....
the battery is magnetized. That's why it only sticks off center. If you flip the magnet over you'll see the difference.
There's another video on RUclips that shows that when you heat a magnet It crosses the electromagnetic Field direction so try doing it on top of a bigger magnet To re-align
If you have some fine iron dust, you could compare the magnetic fields of a soldered magnet and an untouched one. Just place the magnets under some paper and compare. I've never used that magnetic film. Never heard of it until I read the comments. Always used paper and a sprinkle of iron dust. Looking forward to the next video on the subject.
There are magnets that can handle heat, or low heat solder.
Strange to see the Curie effect is irreversible. My Weller solder tip works with this effect, but maybe it's a special alloy.
Why not use two (larger) metal rings to solder the wire on and place magnets on both sides. Win-Win.
The transition at the curie temperature is reversible. But you are confusing something being magnetic and something being magnetized.
Spot welding works great for this type of work.
Put a copper pot scrubber in your solder tip holder.
What about using electrically conductive glue such as CHO-BOND 360-20?
Looks to me like the battery terminal is a bit magnetized causing the wire magnet to move. Just a thought could be wrong but might be worth checking.
Now you will have to solder the exact oposite side of the magnet with another wire an then connect the end of the wires together so you will get back the balanced magnetic field as before and the magnet will stick at the center this time ( if not do it in 4 places or 8 places in both sides ) :)
Normal magnets loose their magnetism when a physical shock occurs - a problem that neodymium magnets do not have. The way neodymium magnets loose their magnetism is heat, and theres specific temperatures given online.
when soldering to the magnet use as low a temperature as possible. With how fast the solder just wicked onto the magnet I can guess your iron is way too hot.
I would suggest having as much contact area between the magnet and the piece of metal as possible, using some flux on the magnet while having solder already on the iron. that way you have the fastest time possible to take your iron off of the magnet before you mess with the field too much.
If you have a temperature controlled iron somewhere that would help a bunch too. (I know it helps me out every day)
Not too low of a temp, but with how fast and how far the solder wicked up the temp was def too high. gotta find a balance for the material. Thermal conductivity, and thermal mass of the magnet; thermal conductivity, temp, and thermal mass of the iron. just a few factors to help decide what temp to use.
But you are correct, too low and it takes too long. There are many different ways to solder a wire onto a magnet and It may be difficult to get it down.
I wonder how spot welding onto the magnet affects the field...
n 65 neo, or higher. copper plate 1/4, use silicon wire #22. Clean magnet with 90% ISO-prop alcohol. I also used two pieces of aluminum # 10 gauge sheet metal clamped, as a heat sink. Worked good for me. I have been using them and TP 4056 to charge lithium cells for a while. A little flux pen helps too. Just some ideas.
I think a small spot welder that is used for welding liion batteries together might be able to do the job better, those should weld without heating the magnet too much
paper and iron filings to visualise field shape.
Have you considered the polarisation of the magnets (and where the polarisation a are?
wire is magnetized now spreading the magnetic field through wire and affecting magnetic field. Same magnetic field over larger mass
I'm wondering how the magnet connections are affected by the electric flow e.g. ionization. Should we expect corrosion?
could you solder a battery holder for the coin style batteries and the put your magnet into the holder?
Maybe the polarity flipped sides N to S??
Dear Julian,
The Curie point of the cheaper NdFeB magnets is ~ 80'C. You did indeed demagnetize a portion of your magnet by soldering the terminal to it. What many people don't know about a 1/2/5 eurocent coin is that it is made of excellent magnetic iron (not copper). You can solder a wire to such a coin, and stick the magnet to it after it cools down, for best results. Oh, but wait.. Brexit :p
UK has never had euros anyway
Yes. And now their access shall become poorer. Wunderbar.
what about all the "useless" eurocent coins we bring back from holiday, already done this with old french francs some of which are magnetic.
1 and 2 pence coins are also magnetic, though perhaps not worth as much as they used to be.
THANK YOU! Good to see someone who looks for a solution instead of a retort ;)
If you want to do this and not loose the power of the magnet. Take the magnet you want to solder and place it on a second magnet that is bigger. 2 or 3 times the size. Then you can do what you just did without loosing any of the magnetic strength.
What if you use a lower wattage iron? 60W seems a bit high for what I presume is leaded solder, especially for soldering to a magnet. In my personal experience with soldering irons, even a 45W iron gets quite hot.
would it help to place another magnet between the battery terminal & the magnet that you have soldered the wire to?
You could try a low temp solder the same as used on piezo elements.
Maybe it's not the heating effect Per Se but the addition of Copper/Tin in the form of Solder and Wire into the magnetic field offsetting it??
What's the brand of your wire stripper?
Heating magnets results in a loss of magnetism strength, In any case, roughing up the surface would help a lot followed by alcohol wipe prior to soldering
I won't say I told you so, but... :P I honestly thought it'd be a lot worse though. Maybe pre-freezing the magnet and sticking it onto a heatsink would help prevent and slow down transfer between the entropies while soldering?
It's probably easier to just take a ring connector, crimp with cable, and sandwich it between two magnets. Easy and basically no mess with glue or solder. In addition you'll get a flat surface for the battery and the magnet ;)
Tried flipping the magnet over?
Spot welding is the recommended method.
Have you tried conductive adhesive?
What about fixing the magnet (with glue, epoxy, whatever) to the opposite side of a conductor that actually makes contact with the battery?
I don't suppose it's as simple as you getting the magnet's north and south poles mixed up? The kind of "stay away from the center, go toward the edge" behavior of the magnet I've seen before when a magnet is flipped upside down.
What is the name of that wire stripper? I would like to get one
Charging the cells in series seems to cost more than in parallel. I've seen so many videos on the TP4046 each charging a single cell and all powered on the same supply in parallel. What is the end goal here?
Would there be any resistance in the magnets? I want to have a battery connected to magnets so i can change out for different LEDs but i don't know if i would have to fit a different size resistor because of the magnets
Solder while attached to a larger magnet. Field less disturbed.
How did this hold up for charging? did it get to hot of anything while charging?
Hey remember you're putting metal onto it which will change the magnetic field of the magnet. Doesn't take much to do a lot. Also you might want to just use a conductive epoxy instead of solder. It's a bit more expensive but you have 0 drawback with it and no chance to permanently alter the magnet
No the heat is causing the particles inside the magnet to excite and change into random orientations he needs to stick it to another magnet when soldering to try and maintain the north south pole on the magnet. The solder itself doesn't effect the magnet because it's tin and lead or silver and is not magnetic.
Try soldering the middle of the magnet,or solder a small piece of metal then stick the magnet to that
Better to spot weld a nickel strip to the magnet and then solder the wire to the strip. Otherwise a thin brass strip folded into a loop with the magnet held in there with epoxy or superglue.
Have you tried flipping the magnet over to see if that makes a difference.
I wonder if you magnetized the battery terminal and it was opposing the magnet?
I don't know much about heat's effect on magnets. But neodymium magnets have 4 poles, unlike the regular magnets which have 2. Perhaps by adding the conductive solder and wire has changed the shape of the overall combo, and therefore the pattern of that complex balance between poles... Shifted it sideways, maybe?
Where are the 2 extra poles?
Just look it up, guys... too long to explain here.
I did look and only 1 thing came up about free energy..... Enough said
LOL!
When I say "look it up", I mean somewhere other than RUclips! Anyway, here is a link: physics.stackexchange.com/questions/12283/if-you-place-a-spring-on-a-neodymium-hard-drive-magnet-it-appears-to-vibrate-in
Hence why I said last time: Don't heat magnets. The area you heated has now become demagnetised. You can test it with a clear jar with some iron filings. Place the magnet on the jar and you should be able to see a pattern where the dead zone is on the magnet. Just don't heat magnets, it's a bad idea...
There exists 18650 battery holders like the AA batteries
The brass wool is a lot more effective than a sponge for cleaning your tip.
didn't you have viewing film? i've seen it in another video, maybe yours or mikeselectric
How about conductive glue? Is it expensive? I could use some for mounting leds on alumium(al is hard to glue).
If you over heat a magnet it loses it's magnetism. So wouldn't current running through the wire heat up the magnet?