Can battery voltage be too high for Yale PIR to work?

[greve]

I have a Yale HSA6300 system which has worked fine for about 2 years. One of the PIRs has now said it needs new batteries but when I install three new AAA batteries, the PIR doesn't initialise.

I checked the voltage of the new batteries and it's 1.6V each (nominal 1.5V). I've tried with two sets of new batteries with the same result - the PIR simply doesn't initialize. When I re-insert the old batteries (each around 1.1V now) the PIR initialises fine and the panel reports low battery.

Is it possible that there's some kind of protection circuitry in the PIR, which prevents over-voltage that doesn't allow the 4.8V to start the PIR initialisation? Or what else can be wrong?

 

[JAmmmmm]

They could be Nickel-zinc batteries judging by the voltage, try some normal Alkaline ones

 

[yaleguy3]

Its simply the wider positive posts on the dura cells etc are wider and don't fit properly and make a good connection