[ltp] Auxilliary external batteries

Theodore Ts'o linux-thinkpad@linux-thinkpad.org
Mon, 12 May 2003 13:25:46 -0400

[ I've cc'ed customerservice@electrovaya.com because I don't like
talking about people (or companies) behind their back....  -- TYT]

On Mon, May 12, 2003 at 11:25:27AM -0400, Evan Leibovitch wrote:
> The Electrovaya PowerPad:
> http://www.electrovaya.com/
> I'd like to be able to use my laptop for the duration of trans-Atlantic
> flights without the battery going. These units seem like a good answer
> to this problem, both systems support almost all Thinkpads, and I don't
> imagine there are any Linux issues surrounding them.
> Does anyone have any experiences with these units? Are there other
> vendors in this field or other solutions that I don't know about? Any
> assistance or suggestions are appreciated.

I've used the Electrovaya, and I *used* to recommend them very highly.
They're nice for a couple of different reasons:

1)  They work on multiple flavors of laptops, not just one

2) It's a lot easier to charge one big battery (the Electrovaya 160 is
the equivalent of four normal Thinkpad batteries --- at four times the
cost) than several small batteries

3)  The form factor is more convenience.

However, the Electrovaya battery, at least, has a very serious design
flaw.  The internal female connector for the Electrovaya is very badly
designed, and is succeptible to sideways pressure that can very easily
destroy it.  Once the connector goes, the battery is useless; there's
no real way to repair it.  I've had two Electrovaya batteries die this
way, and I've heard of at least one other person who has had this
happen to them.  The first time my Electrovaya battery died,
Electrovaya did replace under warranty.

The second time, however that my Electrovaya battery died in exactly
the same way, it was out of warranty.  So I opened it up to see if I
could repair it.  It is very clearly not set up to allow repair; I had
to destroy the rubber seal which goes all the way around the battery
in order to gain access.  However, it looks like it should be possible
to desolder the connector, and attach a one foot "pigtail" cable to
the battery, and then solder a new connector on to *that*.  IMHO,
that's what Electrovaya should have done in the first place.
(Alternatively, they could have used a much sturdier and mechnically
robust connector.)

I haven't had time to to attempt the repair.  I still need to figure
out why the power connector apparently has three contacts which it is
soldered to on the circuit board.  I was only expecting two contacts,
and so I need to do some experiments to figure out what the third
solder joint between the connector and the circuit board is all about.
The other challenge is figuring out how to replace the rubber
seal/gasket which goes all the way around the edge of the battery.  My
current thinking is to use some kind of rubberized calking material
and use that to seal the exterior of the battery (which is composed of
a thin metal sheets surrounding the flat battery packs.

In any case, if you do buy the Electrovaya, be very, very, very
careful about not exerting any kind of force on the plug when it is
inserted into the battery.  It's very to bump into the plug when
moving from one location to another while the laptop is plugged into
the battery.  Ideally, unplug the cable completely from the battery
before moving it at all, in order to reduce the chances that a your
$500 brand-new electrovaya battery gets turned into a paperweight.

						- Ted