Re (2): low battery shutdown

[peter at easthope.ca]

From:	Mike Dee <mikedee4 at gmail.com>, Mon, 22 Feb 2016 06:22:05 -0800
> contacts that electrically connect the battery to the
> laptop.* Dried green crystals have been spotted around the connector 
> ... contacts that electrically connect the battery to the
> laptop.* Dried green crystals have been spotted around the connector ...

No sign of corrosion anywhere in or on the machine.  

> *Perform an XO Full Reset <http://wiki.laptop.org/go/XO_Full_Reset>.*

No problem there.  Brief orange flash is as described.

> *Disconnect the battery, and connect the laptop to AC power*. Now turn on
> the laptop. After the system has loaded, insert the battery.

> *Does the battery LED start flashing red?*

No.  Just steady yellow indicating charging.

> *Does the battery LED start flashing yellow?*

Just steady yellow.

Within about 40 minutes, mousing over the battery icon at 
the top of the screen shows 100% charge.  The battery light 
remains yellow for another 20 or so minutes.  Then changes 
to green.

> Now
> disconnect AC power and discharge the battery while the system is running,
> keeping an eye on the percentage charge.
> 
> *Does the system shut down abruptly with over 10% of charge remaining?* If

Probably about 30%.  Will do it again this weekend to verify the previous observation.

> Capacity test

OK, thanks.

From:	James Cameron <quozl at laptop.org>, Tue, 23 Feb 2016 06:18:55 +1100
> If a couple of full charge and discharge cycles don't fix the
> inconsistency, the battery is close to end of usable life.
> 
> I agree with Paul that power-logs will be useful if Peter wants to
> dive deeper into the technical causes.

Will continue with the tests and tips.  

A battery specialty shop here in Vancouver made a nice job of 
rebuilding a battery pack from an Epson HX-20.  Might let 
them have a go at this battery.  If necessary will find a new 
replacement.

These machines are superbly durable.  The battery pack will be the 
first failure in most.  A modular battery with a "standard" connector 
might be considered in a future design.  Recently I was given a 
Duracell cylinder about 2 cm diameter with USB sockets on the end.
Should run many of little FPGA based machines.

Thanks!                 ... Peter E.




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