I was talking with HP, they implied that there was a battery door lock; but, that didn't seem to be the case based on my test. A battey door lock could help prevent the following behavior.
When I change the battery (remove and replace), the iPAQ does a soft reset.
Does your iPAQ 110 do a soft reset when you change the battery?
Im only running the factory battery for now. I think the soft-reset after installing another battery is needed so that the device registers the correct status of the new battery.