Hello all ptn2 users and everyone else interested. A while ago, my ptn2 battery gave in. It did know longer hold a full charge. I decided that there is no use of it furder and I removed the battery and the screw wich holded the cover. Now I like the fact that the unit tells me that no battery is installed. But here is the thing: I was expecting the date and time to be completely rong, as it was more than a month without a battery, and I always thought that it must be the battery that also holded the clock settings. However, now I found that the date and time was still correct. This leads me to think that the ptn2 like computers, must maybe have a small battery in the motherboard or somewhere wich does this job. Intresting. Wunder what is the case with other units such as ptr2?