Re: [NTLK] Rebuilt battery pack

From: Doug (dougp_at_ispinn.com)
Date: Fri May 13 2005 - 07:39:18 PDT


> I split the old pack in two halves
>and replaced the old cells with brand
>new 2300mAh ones.

Split down the original, chemically bonded seam. Nice. That's how I did mine.

Ask your local plastics professional supplier for a plastic solvent that will bond acrylic (?). I was able to bond the two halves of my pack together using the solvent, letting capillary action pull the solvent through the length of the crack and honest to goodness it looks like it's never been cracked open. Frank is experimenting with the same technique, IINM.

>Wasn't too difficult but the pack is now
>a tiny bit too large (I think the new
>batteries may be ever so slightly larger)
>and won't eject without gentle tapping on
>the side of the Newt.

Be thorough in cleaning out the glue residue on the inside of the battery case. Be extremely thorough.

I don't know if the plastic sleeve is needed on the batteries (any experts out there agree or disagree?) but you can gain some much needed clearance by removing the plastic sleeves from the cells. I don't know, though, if the plastic is needed to protect against cell rupture or electrolyte seepage.

Without going into gory detail and hurting my brain, I believe the thickness of the plastic sleeve surrounding the battery raises the case because the plastic adds not just height, but (more importantly) WIDTH to the battery, pushing the battery case top up to allow for the extra material. A small reduction in battery thickness results in a bigger reduction in overall battery pack height. My brain is starting to hurt. I'll stop now.

I have a set of calipers. Next time I assemble a battery pack, I'm going to record the width and height of a pack. After reassembling it, I can measure it again to be sure it's the same or less.

(still looking for a creative, technical job somewhere...)

Doug Parker

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