I have a thinkpad edge 13, with the package tp-smapi-dkms installed. As described in these instructions, I have also run sudo modprobe tp_smapi, and added tp_smapi to /etc/modules
Before upgrade to 11.10, I used to be able to change thresholds for stopping battery charging. I would open the file /sys/devices/platform/smapi/BAT0/stop_charge_thresh as administrator and change the value from 100 to 85. Now, I am no longer able to directly edit that file. I also tried sudo echo 85 > /sys/devices/platform/smapi/BAT0/stop_charge_thresh but get Permission denied.