Wickes Wireless Alarm Giving False Low Battery Warning?

[macman81]

I have a Wickes 710702 wireless alarm system, with 4 PIR's and 3 magnetic door sensors. The control panel was showing a low battery warning. I changed the batteries in one of the door sensors because the little red neon was not coming on when it opened, it's now OK.
But I'm still getting low battery warnings. I can clear it by switching off the alarm, but it comes back on within about 20 minutes.
The other 2 door sensors are showing red neons when door is opened ,so presume they're OK. The PIR's are supposed to flash when you go within range if the batttery is low, but none of them are doing this.
What should I check next? Could it be that a neon has failed on one of the PIR's so it's not showing a low battery? I could just change all the other batteries but there's 10 of them in total.
I've had this system about 6 years and for a basic DIY kit it's always been very reliable.

 

[Atilla]

I've had this system about 6 years.....

please say you`ve been changing the batteries every year ?

 

[macman81]

No, I've been changing them when they show a low battery warning. Typically about a 2 year cycle, but I think the one I just replaced was the original-it's a side door that is rarely used. No signs of battery leakage or corrosion, if that's what you're thinking.

 

[breezer]

no, change all the batteries to be sure