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Should i use magnets on flat tops?

ExLaserSquad

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So i got some 18650 flat tops and a flash light basically i need two 18650 batteries in it so can i just use magnet on one battery so it can connect to other battery?yes magnet gets stuck btw does 2 metal idk maybe it will have some friction aswell but is it dangerous?i think i can wear my heat resistance gloves incase anything can go wrong?Please give me ur suggestions thank you.And yes batteries does not really rattle in it once u close it fully and then even if u throw it somewhere nothing really happens seems like they are fit unless i open them then well then i have to spin the bottom of flashlight to open it up means it can affect batteries while i do it pretty much so far once they are close they seemed like they are properly fit so what u guys suggest?is it fine?or should i use some super glue on magnet?so it wont rattle around and just stay at its position.
 
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Alaskan

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Unless you keep the glue from getting under the magnet, it might insulate it from the battery. I've also had concerns about using a magnet between two flat top batteries. My concern is if it somehow gets off center and touches the side of the host inside the battery tube and shorts the bottom battery to the case. Has that happened to me? Not yet.
 

ExLaserSquad

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well its just its hard to find good button top batteries in my country so i had some flat tops i have been using it like that but i just had this concern not like anything happened as of now
 

GSS

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Many use a rubber o- ring over the magnet thats close to size of the battery to help isolate it from sliding inside the host.. It's sometimes hard to find a o-ring thats thinner than the magnets thickness, but they are out there in variety pack with different sizes..
I would only use a neo magnet for strength and no black residue.
If you can solder a tiny tab of solder on the flat top positive without heating up the cell too much thats another option.
 

BowtieGuy

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Those are some good answers for you from GSS, Alaskan, and Anthony.

Another option is that if you have some room between your batteries and the battery tube, you could also try either a thin plastic or cardboard sleeve to keep the magnet from contacting the host, or in a pinch maybe even some tape around the joint between the batteries where your magnet is.

I have used magnets on occasion, but as GSS mentioned, always use neodymium magnets to reduce the chance of the magnet slipping and shorting against the battery tube.
 
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GSS

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^^^Oh yeah^^^ a plastic sleeve is great :)
 

Encap

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well its just its hard to find good button top batteries in my country so i had some flat tops i have been using it like that but i just had this concern not like anything happened as of now
You can always order a button top battery online for shipment to any Country instead of using a magnet if it bothers you to use one.
 

ExLaserSquad

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Well the thing is not many delivers to my country but well i did use neo magnets and yeah they are strong of course but yeah i could try some tape nice suggestion this should stop the magnet from constantly trying to stick to other battery or cardboard ill try both of them which one works best ill use it.Yeah i do have some room i think cardboard sleeve is a better idea but just incase ill try both cardboard sleeve or a plastic sleeve or some tape thanks for the suggestions everyone.Though i have been using it for more then a month now so hopefully it will be fine in the future aswell.
 
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paul1598419

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This question comes up here every so often. I have some neodymium magnets that are good for this purpose, but the chance of one shorting to the case has kept me from using them. I got some 3500 mAh LG 18650 batteries from liionwholesale.com that are rated at 5 amps drain which have been good enough to use with most anything I've built. But, if you want really high drain batteries, 20 amps or higher, you will have to get unprotected cells which are the flat top ones.
 

Cyparagon

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Solder a nipple to it. Always works for me. Easy, cheap, fast, sturdy, and far lower resistance than a steel button top or the thin film of nickel on a magnet. A magnet, despite being inferior in every measure for this application, will still work fine.
 

ExLaserSquad

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well i would if i could lol i never soldered anything before so i dont think i should try it with battery can be dangerous but yeah the flat top work better for me then those button top as i need some high drain batteries and getting good button top is not easy here so thats why i started using these.
 

Anthony P

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I have soldered copper 4-40 washers on battery contact boards several time to accommodate flat top batteries. Never tried to solder directly to battery.
 

hakzaw1

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I use JB weld for lots of things...but since it has iron in it ---you will not like what it does to magnets.
The JB wil 'creep' around the magnet. a sleeve is what I use & only between batts never at either end,-- impossible to short out.
 

barthchris

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Want to have fun? Mix iron oxide powder(stuff used for thermite) to silly putty then add a neodymium magnet. Lots of nerdy fun. Lol


I use flux and a large iron with a lot of thermal mass to quickly solder a button on top of the flat. Need a clean freshly tinned tip and solder will bond in less than a second. I

With magnets, I do wonder about their conductive properties. Not like were using massive amounts of current but still. That said Ive used magnets before and never noticed and high resistance issues.
 




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