Re: [NTLK] 2100 + Battery Rebuild = Fried Newton

From: Joel M. Sciamma <joel_at_inventors-emporium.co.uk>
Date: Sun Nov 02 2008 - 16:36:21 EST

Woody,

> I wish we knew what was going on. I've been using a battery pack that
> I re-celled probably 4 years ago and one that I recently did.
> But I have re-celled more than 50 eMate packs, and though I have
> occasionally had a bad solder joint I have never heard of one leading
> to damage to the newton.

I don't think it has anything particularly to do with rebuilt packs,
it's just that the heating and the high currents (that are normally
associated with charging batteries internally) stresses what are
getting to be elderly components. Failing tantalum electrolytic caps
that go high ESR experience a lot of internal heating, which can be
terminal. We could do tests of those caps with an ESR meter and swap
those out that look bad but it's easier just to avoid the problem.

My feeling (as I don't have a complete explanation) is that charging
batteries in the MessagePads is probably not a great idea at this
stage and in any case it is a very slow way to get your machine
recharged. Having a set of charged cells or primary cells at the
ready means you are up and running again in seconds, the Newt stays
cool, NiMH cells survive in good condition longer and you can use any
battery technology that comes along.

Joel.

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Received on Sun Nov 2 16:36:36 2008

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