Loose negative terminal in Headway cell

J

Jaak

1 mW
Joined
Oct 13, 2009
Messages
11
Hallo to all.
When I was firmly (I think too firmly) screwing 40160 Headway cells to each other head to tail (I used threaded M6 bars), it appeared that at the end, when the negative terminal became fixed to the positive terminal of the other cell, it was still possible to rotate the cell body.
This means that at that moment the negative terminal was fixed the cell body was still forced to rotate a few mm’s.
The voltage remains OK.
I have addressed this query to Evassemble, but until now there’s no reply.
Does anyone of you know if this is a problem or if this will cause damage to the cell interior ?
What exactly is happening in the cell interior ?
Thanks so far.
 

Attachments

  • DSC03336.JPG
    DSC03336.JPG
    101.2 KB · Views: 1,173
Does it smell funny? I'd pour some epoxy over the area between the bung and the black part immediately..
 
Dang. I was hoping the new black epoxy they are using now was a little more resilient than the older snot green stuff. I have done this to hand full of cells in the past. I have not detected anything negative (pun :p )happen to cell performance. I have removed old epoxy joints and filled in with new epoxy. Otherc cells I have left as is and used some ultra baby channel locks to grip the negative terminal when attaching and tighten the adjacent cell. I've had no problem with those cells yet either. Now i always use the channel locks to attach cells end to end, just to avoid this. I have posted a pic of these nifty little pliers below.

You'll definately want to avoid twisting any further though... it will either tighen or loosen (not sure which) the wrapped film inside if you do. I assume that would be bad and cause some shorting within the cell at some point.
IMG_1632.JPG
 
Thanks for your replies.
Those "nifty little pliers" are a good idea.
So far I am a bit assured as Scoot did not note any los af performance.
Does anyone know a picture, photo or exploded view of the construction of the inside of a Headway cell ?
That will make it more understandable of what exactly the case is when this happens.
Thanks
 
Its like a roll of paper towels. LFP has a vid posted where he cut one apart. I would try to rough up the black part and sides of the bung if possible so the epoxy will stick to both. You don't want the cell drying out.
 
Were's that video from LPF and what does it mean "... you don't want the cell drying out."
Thanks
 
The cells have an absorbed electrolyte that can slowly evaporate if there is an opening to atmosphere. Or even worse, if the opening is large enough the lithium can react violently (fire) with the air. From what I remember in Luke's vids the headways didn't react much to the air though. Or at least his cells didn't.
 
You must log in or register to reply here.
Back
Top