Have you checked the battery parameter (I think it's 9) in the HR92 menu? if set to the wrong type (there's a choice of three) it could be failing the battery early.
It is not the contacts. They have been checked, cleaned etc a few times and also checked that there is a good tight fit. Also I don’t think bad contacts would result in a signal to base at very regular intervals of 3 months. I should have put the batteries to one side to check but unfortunately put them in a bag of other used batteries to be dropped off at a collecting point and I can’t identify which they will have been. I’ll know by March!
Have you checked the battery parameter (I think it's 9) in the HR92 menu? if set to the wrong type (there's a choice of three) it could be failing the battery early.
It’s the menu in the HR92. Menu item number 9. Press and hold the main button down on the HR92 and the menu appears, sometimes you get the binding menu first so try again, then using the cap/wheel turn to item 9.
With respect to my odd HR92 it is now used in another zone and I won’t know until March whether it has been the location at fault or the HR92. If the batteries need replacing in March then it’s the HR92.
Addendum:
It is not March yet, not far off, but the batteries need replacing and thus it is the HR92 eating them. After the last battery change I changed the position of the HR92 swapping it from one zone to another and for the past few months it has been alongside me and about 3 feet or so from the control panel. The signal has come up saying the batteries need changing. I have had this one since December 2014. Fair to say it has always been like this. I suppose even after 2.5 years it is still a manufacturer's defect. All the other HR92s are fine.
Have you tried connecting a multimeter in mA mode in place of the battery shorting clip at the top to see if this HR92 has unusually high idle current drain or unusually high drain when the motor is turning ? You could compare it to another good one...