Pyronix Deltabell (wired) Battery Change Interval?

Had a few things to sort out with my alarm recently and as the Deltabell is nearly 4 years old and on the original battery I want to replace.

When I speak to my local distributor he said he has never sold a replacement battery for these?

My question is how often are the batteries replaced as standard in the trade and should I change now whilst I have the ladders out or is it safe for another year or possibly more?

The alarm is in a rental property and the less maintenance during the tenancy they better.

If its a Wireless siren I would replave it after 2years but you may get a third year. If its Hardwired then it'll last many more years, it will not flag up a fault of any kind however if power is removed it will not sound under its own power. Best way to test is to remove bell fuse in main panel and you should hear siren sound under its batterys power, if its a weak sound this would siggesr batt is low. I've never replaced a bell batt in 13 years, usually replace the whole unit after 10 to keep up the deterent effect.

On a related subject why are the batteries in a panel replaced every 4 to 5 years then, are they a different battery type?

Service Engineer thanks, this is a hard wired bell box and I'll take your comments on board along with the fact my distributor has never sold a spare battery and I'll leave it for now. I dug out my install notes from when I installed the system and this is a grade 3 Deltabell Plus which claims to perform a battery test every 24 hours and should create a fault via the tamper circuit if the battery fails this test. In any case there is no fault reported and the siren works without mains and panel battery power as I checked this a couple of days back so all is good.

Paulj48, yes the panel battery is a totally different battery technology (Sealed Lead Acid) which are usually changed as a precaution to prevent call outs in between services as a failing panel battery can cause a whole range of other random and seemingly unconnected issues.

batteries fail, but the easiest test, is to remove power at the panel to the bell and does it ring.

replacing for a more modern and fresh bell box does tend to give the extra deterrent.

4 years old and its a hardwired bell??? I wouldn't have expected the battery in the bellbox to have gone yet.

wireless tend to be lithium batteries
hardwired bells tend to be NiMH
panels tend to SLA

however that's not always the case. The NiMH batteries are available all over the place if required.