[chbot] Battery Pack - the 27 chocolate fish challenge

[Wes Edwards]

Is this link of any use?  It deals with the same 18650 Li-Ion cell.
http://www.wired.com/geekdad/2011/09/18650-things-to-do-with-an-old-laptop-b
attery/


-----Original Message-----
From: chchrobotics-bounces at lists.linuxnut.co.nz
[mailto:chchrobotics-bounces at lists.linuxnut.co.nz] On Behalf Of
kerry at manukadesign.co.nz
Sent: Tuesday, 18 October 2011 11:17 a.m.
To: Christchurch Robotics
Subject: Re: [chbot] Battery Pack - the 27 chocolate fish challenge

Could you not just bypass the two dead cells and leave the in place?

Kerry

Quoting Mark Atherton <markaren1 at xtra.co.nz>:

> Hi All,
>
> Last night Paul L was kind enough to give me a busted battery pack
> from an electric drill - www.idesignz.org/BP/battery_pack.jpg.
>
> The pack contains 10 x
>
<http://www.idesignz.org/BP/DM_IMR18650E.pdf>http://www.idesignz.org/BP/DM_I
MR18650E.pdf
> Lithium Ion cells.
>
> Two cells are busted, hence the reason for the unit being thrown out,
> and of course they are in the middle.
>
> The cells are capable of 20A discharge each, and two cells are in
> parallel. Short circuit current is likely in the order of 100A per
> cell given internal resistance of 35m ohms and 3.7V terminal voltage.
>
> The connecting tabs are copper sheet that have been sport welded onto
> the end of the cells.
>
> There is a black plastic saddle that the cells are attached (glued
> ?), with about 0.5mm clearance between cells. Max working temp is 65C.
>
> So the puzzle of the day is how to disassemble the pack safely.
>
> My inclination is to start by cutting vertically with an abrasive
> non-metallic dremel disk - at least the neighbours will be isolated then.
>
> Might then be tempted to soak in white spirit to dissolve the
> adhesive to the black saddle, but that may do nasty things to the
> green cell insulation.
>
> If you short adjacent cells you **will* start a very nasty fire.
>
> Any other thoughts ?
>
> -Mark
>
>
> _______________________________________________
> Chchrobotics mailing list Chchrobotics at lists.linuxnut.co.nz
> http://lists.ourshack.com/mailman/listinfo/chchrobotics
> Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/
> Web site: http://kiwibots.org
> Meetings 3rd Monday each month at Tait Radio Communications, 175  
> Roydvale Ave, 6.30pm
>
> When replying, please edit your Subject line to reflect new content.
>




_______________________________________________
Chchrobotics mailing list Chchrobotics at lists.linuxnut.co.nz
http://lists.ourshack.com/mailman/listinfo/chchrobotics
Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/
Web site: http://kiwibots.org
Meetings 3rd Monday each month at Tait Radio Communications, 175 Roydvale
Ave, 6.30pm

When replying, please edit your Subject line to reflect new content.