Power for my laptop
I own a small IBM Thinkpad X40 and I am quite happy with it, it's close
to 4 yrs old now and the stamina of the accumulator failed over the time
down to about 2.5 hours (from about 5-6 hours). This is still a fair
time for mobile usage, however I decided to buy a new accu these days.
It's about 179 Euro which is quite expensive.
This brought me in contact with charging times, mobile usage, design
caps, etc and I wrote a small perl script which gathers some statistics
and stores them inside a rrd database. On the graph below you can find a
typical example of a charge proccess. Let me explain the graph a little
bit. The script gets its data from the command envstat -r
every five minutes. The data is stored in a rrd database. The design cap
of the accu (blue area) shows what the total amount of power was when
the accu was new. The green line shows the last full charge. This is the
value for the last full charge when the accu showed 100% charge. So as
you can see by this graph, this accu has lost almost about 50% of his
capacity.
The red line shows the current charge, right now the charge proccess is still running, please note how long it takes for a full charge and how slow the proccess is when it climbs up to 100%.
Right now I won't post the script here, there is some cleanup work to be done, however I think I might finish it by tomorrow and I will post it here. There is still some documentation missing.
The script is monitoring my laptop for the next 3 years, I wonder what the new accu will look alike - what about the curves, etc.
