I have 1 HSM100, my experience is the faster you set them to send out updates the faster the battery's die. I had 1 set to send out regular updates (Temp, light level, batt level ) every 6 minutes and it lasted only a couple of months. I replaced the batteries with fresh Energizer's and still only a couple of months. So I am either going to have to greatly increase the regular updates, or maybe try lithium batteries.
It just didn't seem logical to me to expect temp / light readings every 30 minutes or so.
JMHO
StevenE