[Testing] Battery charging and discharging level on OLPC

[James Cameron]

On Fri, Mar 19, 2010 at 02:45:54PM +0530, johan sahabandu wrote:
> I just started to search for how testing of Battery charging and
> discharging level on OLPC xo-1 and 1.5
> I need to test battery charging & discharging levels in OLPC, so I
> would like to have  a clarification about the method of testing same

I suggest you write a test plan in the Wiki based on the normal
operating cycle of the battery.  There isn't one there at the moment.

The nearest test plan that relates is
http://wiki.laptop.org/go/Tests/Suspend_Resume

To get you started, consider the battery as part of a power management
system.

The system has the following variables:

- chemical state of charge, the amount of energy that can be withdrawn
  from the battery, which cannot be assessed without changing it,

- stored state of charge value, a numeric value stored in the battery
  management chip which is inside the battery case,

The system also has the following inputs:

- DC input socket on left side of laptop, to which you attach the AC
  adaptor supplied with the laptop,

- the power button,

- the power management settings in the Sugar control panel, which you
  can access by right-click on the central icon in the activity view,
  selecting My Settings, then Power,

The system also has the following outputs:

- the power LED indicator on the front panel to the left of the power
  button, shaped according to IEC 5009 (line partially within a broken
  circle),

- the battery LED indicator on the front panel to the left of the power
  LED indicator, shaped as a rectangle with a nipple to the left,

- the battery indicator in the Sugar Frame, (press the Frame key, which
  is an open rectangle above the erase key, then right-click on the
  battery icon),

In writing the test plan, you could consider:

1.  do the indicators properly indicate the state of the system, despite
user actions such as removing or inserting battery or external DC?

2.  does the system operate correctly near important boundaries of the
variables?

3.  does the stored value in a battery display the same on other
laptops?

4.  are gradual changes to the state of the system (charging or
discharging) properly reflected in the outputs, and in the unknowable
chemical state of charge?

Hope that helps.

-- 
James Cameron
http://quozl.linux.org.au/