Issue while upgrading firmware

[Richard A. Smith]

Mitch Bradley wrote:

> It is pretty unlikely that the battery would die during the reflashing 
> process, which completes in a few seconds.  But there have been cases 
> where people paniced and removed the battery right in the middle of 
> reflashing.

During one of the many NiMh EC bugs sprees. I bricked a laptop because I 
plugged in what appeared to be a charged battery (but wasn't) and the 
External power (AC as we call it) adapter was pulugged into a strip that 
was not powered.

And considering the shipping model it may not be as unlikely as you 
think.  The EC does not do well with shipping self-discharge since the 
SOC and the ACR values do not change yet the battery loses charge.  The 
EC eventually corrects but that won't happen until the voltage goes 
unexpectedly out of whack.  The V curve of the battery when the capacity 
is low is very non-linear.

In the slow-boat shipping case where the batteries sit for months and 
then have to wait around to get transported to the remote areas I can 
totally envision there being just enough power to get you started and 
then die during re-flash.   Murphy agrees.

Thats why we require battery and ext power.

-- 
Richard Smith  <richard at laptop.org>
One Laptop Per Child