Making terminal connections with 18650s

[MilchstrabeStern]

I'm machining a custom host this week for an M140 diode and will be powering it off of two 18650s and a BlitzBuck 1.8A adjustable driver. I received my protected 18650s (panasonic) today, and realized they don't have raised positive terminals. What is the typical means by which to achieve + to - contact? Small Nd disc magnets? I just don't want to accidentally cause a short with the host, since it will be connected to the negative terminal.

Edit: The host will be aluminum and therefore non-ferrous.

 

[Livinloud]

Magnets work fine. Some people solder blobs on their batteries but this is dangerous if you dknt k Bhutto ow what you are doing. My flat tops work in all my lasera without magneta so try that out first

 

[Hemlock_Mike]

IF they don't make contact, I will make a quick
wipe of solder across the + terminal. Buff it clean
an put antiox oil on it. Use that oil on all contacts -
especially aluminum and dissimilar metals.
HMike

 

[Cyparagon]

Some people solder blobs on their batteries but this is dangerous if you dknt k Bhutto ow what you are doing.

Are you okay? Did you have a seizure in the middle of that sentence?

 

[Pi R Squared]

Rofl :crackup::crackup::crackup:

 

[Zeebit]

He's probably on his phone but still :crackup:

 

[Livinloud]

Hahaha wow! i just realized what my phone corrected to. Must have been in a rush since i normally reread my posts many times

 

[KRNAZNBOY]

lol and i was just on one of your threads telling that guy who was disrespecting you to type right lol

Just Kidding i love you livinloud

:beer:
-Matt

 

[Livinloud]

Hahaha right, timing was good. I mean heck, I'm posting this on my phone. I post 1/2 what I write on my phone but that is by far the worst post I've ever done

 

[KRNAZNBOY]

Oh actually i have this problem too! I ordered NCR18650Bs and they have flat tops! Can you put a neat solder blob on it easily? I dont want to mess my batteries up. Especially at $9 per cell!

Dont want to use magnets cause the ones i have are too thick and i just dont feel right with such temperamental fixes.

:beer:
-Matt

 

[Livinloud]

Id rather use the magnet then solder a battery. You can get cheap thin magnets, that's what i have and that way you can use them as flat tops if you even need a shorter cell.

 

[Flaminpyro]

Don't use magnets inside of a laser !!!

If you drop your laser or for what ever reason one of your magnets moves and shorts to the case you could blow
up the cell due to a short circuit with the magnet and the host !!!

Get a hot soldering iron so you don't have to keep it on the cell for very long, clean the cell where you plan on
putting the solder blob with some sand paper or a eraser and use some solder flux to help you make the solder
stick easier and go for it.

Never use a magnet inside of your laser, they are fine when your charging a cell but not inside of a host where
they can slide to the side and short the battery to the case !!!

 

[KRNAZNBOY]

Ah try that's all you need huh. I will do that thanks flaminpyro!

:beer!

-Matt

 

[djQUAN]

I used these magnets (link) from FT and stuck one on top of my panny 3400 cell since my nitecore flashlight can only accept button tops due to the mechanical reverse polarity protection.

I don't like using solder for making button tops since solder is a very soft metal so it deforms when squished and in the long term results to intermittent contacts. If you really wanted to, there are brass pillar things (5mm dia x 2mm thick) from FT that can be soldered on the flat top cells to make a stronger, more reliable button top (couldn't search for the FT item, FT site is blocked here at work)

 

[Livinloud]

magnets sliding :thinking: you must be using some weak magnets????? I literally need to pry mine off my batteries by sliding something thin under it and even then sometimes i cant get them off

 

[Bionic-Badger]

I also think those rare earth magnets start to oxidize if their protective nickel coating is damaged -- which might happen from impacts or other stuff inside the host. Then you'll see all this annoying powder and stuff everywhere clinging to stuff and maybe shorting out connections.