If I set the following two thresholds:
echo 40 > /sys/devices/platform/smapi/BAT0/start_charge_thresh
echo 80 > /sys/devices/platform/smapi/BAT0/stop_charge_thresh
I get an unexpected behaviour. If the battery is below 40% when I turn on my laptop, it does not get charged at all. The expected behaviour is: the battery gets charged until 80%. I'm using a ThinkPad X200s with tp_smapi 0.40 and related hdaps (not the kernel one).