magnets, something really weird happened today

[vapero]

I sometimes use a magnet as a spacer on my battery to reduce the throw on my 4nine and works perfectly....

today I set up my mod changed batteries and went out, everything was working great but I did notice that my battery was draining much quickly than usual, I just took it out and checked the voltage with a multimeter and read 1.8v!! this has never happened to me, so I took another battery placed the spacer and checked voltage, 2.2. there is when I figured that my magnet has lost its conductivity, tried again and it read 4.2v, tried my over-discharged one and 3.8v...

what exactly happened? did the magnet lost its conductive layer because of friction? or heat?

 

[bussdriver]

Clean 'em real good; maybe sand them lightly.

 

[The Cloud Minder]

I sometimes use a magnet as a spacer on my battery to reduce the throw on my 4nine and works perfectly....
-
If I understood what you meant by the above, maybe I could help you more, but ... electricity and magnetism are part of the same thing. Run electricity thru a coil around an iron bar and you have an electro magnet. It's possible you cretaed a condition that basically conflicted with the magnetic field of the magnet somehow.

 

[drunkenbatman]

what exactly happened? did the magnet lost its conductive layer because of friction? or heat?

If I'm understanding -- and I'm legitimately not sure I am -- it's the heat or you got a short. When magnets get hot it can demagnetize them -- with cheaper ones (especially in some clones) this can happen faster.

e.g., if you are soldering a magnet to something for a gadget while hanging out on rooftops, it'll lose a lot of it's magnetic charge. Any type of short can knock a magnet out hardcore, or a not-so-great connection can cause heat buildup, or an atty pin being in the wrong place, etc.

 

[Rickajho]

If this is one of those coated neodymium magnets that's really not a good idea to use it as a battery contact/spacer under high amp conditions. Most of them are coated with nickel (cheap ones may even be zinc coated) - to protect the magnet from oxidation breakdown - and aren't meant to be used as an electrical conductor. No idea why yours lost it's conductivity properties.

 

[BlkWolfMidnight]

Has anyone ever found the electrical conductivity of magnets anyways, just curious in truth as I know they are used in high amp switches for power stations but I'm more then sure I recall when I worked with forklifts the gateway for the main power was a magnetic throw system however the magnets only pushed two copper plates together when charged.

It would be interesting to have someone test this actually and see if different types of magnets rate on different conductivity scales. Just a though

 

[crxess]

Dirty=dirty
Oxidation=oxidation

Both naturally occur and need to be attended to. Alcohol, soap and water, vinegar or fine(very fine) sand paper.

Good luck

 

[drunkenbatman]

Has anyone ever found the electrical conductivity of magnets anyways, just curious in truth as I know they are used in high amp switches for power stations but I'm more then sure I recall when I worked with forklifts the gateway for the main power was a magnetic throw system however the magnets only pushed two copper plates together when charged.

Nog, they are. Though in general (as I recall) only the neodymium (rare earth) and ferrite (iron, etc) ones are -- some of the cheap fridge magnets aren't as they're ceramic. The nickel plating is to improve conductivity -- because neodymium is really prone to corrosion and _super_ brittle -- but with the magnet you automatically get negative > positive flow.

It would be interesting to have someone test this actually and see if different types of magnets rate on different conductivity scales. Just a though

They could, and I'd read it, but for our applications I believe it's just a selection of neodynium magnets being used of various qualities and I'm not sure how you'd go by brand names -- perhaps starting strength? By the time it reaches retail everything is a no-name removed from a larger batch (really talking industrial uses, and recently toys as the price has dropped).

e.g., to make one of these you take the $X rare-earth elements, bake it into a disc, apply nickel coating, and at some point magnetize it along the way. If that's done cheaply or something is off with the makeup of the magnet, it'll demagnetize faster under heat (e.g., not want to direct current one way), which you'll get from buildup or a short.

I believe you can measure the strength of the magnetic field strength with a compass... but it's a bit outside my bailiwick. :/