My magnet pack is working!

[markz]

I have five 4S 4P in 26650 holders from Fasttech, with Nickel Strips from SuPower, 5mm x 5mm Neodymium Magnets N50 magnets off some random ebay seller. I ran short of magnets, and figured I'd solder the strips to the magnet. I had thick 60/40 solder, didnt work too well even with Rosin Flux, so I went with a thinner 63/37 solder and the solder joint is good.
I only have enough magnets now, to do two packs of 4S4P. I will order some round 10-11mm (D) x 2-3mm (L) Neo N50's.
One thing I did notice is when the little patch is ripped off on the pos (+) side from detabbing, the magnets have very little strength to stay. With the patch on, there is more, but its still quite less then the neg (-) side of the can. Maybe for that side I will get a thicker N50 magnet, perhaps 10-11mm by 5mm (more expensive too).


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My theory is to have something around the edges of the magnet, so it stays centered in the holders. Maybe paper, glue/epoxy, or acrylic something anways to give the pos (+) more stability. If it works out well do it with the neg (-) side too.

Heat from soldering does demagnatize the small 5mm x 5mm magnet. Clearly the feel is not as strong. I used thick solder so used more heat then necessary.

Magnetic Strength: Throughout this article, magnetic strength is the key measure. The product of B times H is often used to described the strength of neodymium magnets. For example, grade N42 magnets have a maximum BH (called BHmax) of 42MGOe. This number directly relates to Pull Force Case 1, the attractive force from a single magnet stuck to a large steel plate. You could also express this as magnetic field, measured in Gauss, at some specific location. We specify Surface Field in Gauss, measured at the surface of the magnet. Magnetic Strength is not power, or work, and cannot be expressed in terms of power.

Reversible losses: Up to the MaxOpTemp, you will see some loss of magnetic strength at those elevated temperatures. When you bring the magnet back down to room temperature, it returns to the original strength. These losses are small, typically within 5 to 10 percent.

Irreversible losses: Above the MaxOpTemp, some magnetization is lost. When you bring the magnet back down to room temperature, it will be weaker than it was before the heating process. A magnet that has had irreversible losses could theoretically be re-magnetized to the original strength, or very close to it. (K&J Magnetics does not offer re-magnetization services for demagnetized magnets.)

Permanent losses: Above temperatures where the magnet material was originally sintered, structural changes will occur to permanently demagnetize a magnet. No amount of externally applied magnetic field will bring the magnet's strength back. For neodymium magnets, this temperature is very high, typically above 900°C to 1000°C.

 

[agniusm]

Those magnet builds seems dodgy. If you went this route, why not buy magnets that are diameter that fits into plastic holder square tight?

 

[markz]

I am, 10,11,12 mm diameter by 2 to 3+ mm.
I just lost out on a bid on ebay today, but I would have over paid. Found some regular N50, N52 Neo's in the 12mm x 2mm range.
Those magnets are just magnets I use on the fridge.

I just wanted to see if I could solder onto the magnets and see how much magnatism was lost.
I did do another trial solder today, isopropyl clean, Rosin Flux, 63/37, iron heat just right, soldered on the magnet side.
Lost magnetism to about the same extent as the 100% setting for iron, iron on backside.

I got a few more ideas I will try. I'm just fooling around until my parts come for the welder.

Maybe next magnets and epoxy. Very thin strip of epoxy from battery to magnet, maybe out of a needle.
I will try the drilled hole through tab and solder backside method again. This time instead of onto battery, its onto magnet. I will try different size holes. I think the bigger the better.

More expirimenting, I still cant measure current for some very strange reason. The backside of my DMM mentions 2 fuses, but I only see one fuse next to the 9V battery.

 

[kdog]

Re iPhone photos
Take a photo, email it to yourself, choose appropriate resize to do the email. Save resized photo. Use that one.
That's what I do. It's pretty quick.

 

[whatever]

have you considered the force placed on the electron flow by the magnetic field?
the electron flow have to cross the magnetic field right near the magnet edge,where the field is quite high, I would expect there will be some consequence to this. The magnet or the conducting strips will feel a force at right angles to the magnetic field. I'm guessing you will loose some energy using magnets.
The energy felt by the conducting strips and magnets has to come from somewhere i.e. the current flow.
Whether or not it will be a significant loss of energy I have no idea. In theory if the current is high enough the magnets will move position, if they cant move position by gluing them, the energy might materialise as heat in the magnets or conducting strips.