I think this is the normal alarm where you need to change the battery, not those with a 10 year sealed battery.
There's no reason not to buy a 10 year smoke alarm anymore, as the cost of a new 9v battery every 6 months makes the old ones much more expensive in the long run.
I have a reason.
I bought my mother several Fire Angel 'Thermoptek' 10 year alarms but the experience has put me right off any supposed long life alarms. They were being distributed by fire departments in the UK so I hoped they'd be trustworthy models. Instead they gave my mum quite some grief with false alerts and I eventually took one down.
It sat in my drawer for 6 months and when I finally got around to reactivating it the 'low battery' chirp immediately started up. It had only been activated on her ceiling for 2 years !!!
She'd moved in the meantime and we left the other 2 up on the ceiling so I'm not sure how long they lasted.
To be fair that's just one brand - but it's hard not to be put off by this experience when I purposefully bought some of the most expensive alarms I could find. They were nearly fifty bucks each.
I was always sceptical of the 10 year claim and was really just after a good quality alarm - the perma-battery was only a bonus. Being a realist, I figured if I got 5-6 years out of it I'd be happy but in the end I didn't even get half of THAT.
I've decided to stick with 9V models for now. YMMV.
Agree, always found the 10 year ones started chirping at 18 months. Returned them back to Mitre 10!
I've been happy sticking with 9V models too. The batteries tend to last a very long time, and places like Countdown and Bunnings tend to have pretty good deals on Alkaline 9V batteries too
Unfortunately I didn't find any of these in stock at Bunnings Manukau
I saw them in stock (quite a lot) at Grey Lynn (yesterday) and New Lynn (today).
Okay I was in Bunnings today for something else entirely but I happened to wander through the smoke alarms isle and noticed a couple of mini smoke detectors (10 year) similar to the Cavius ones - but half the price of Cavius. Still quite smart looking. And the standard sized 10 year alarms from the same brand can be had at $32 for 2 (so $16 each). That's very cheap even if you only manage to get 4+ years out of them.
Not exactly a cheapies 'deal' but if anyone did want to pick up some long life ones, then Avantime is right the prices are much more attractive than they were 3-4 years ago.
Family Shield 10 year miniatures, $25 (single) or $48.50 (twin-pack)
Family Shield 10 year regular sizes, $32 (twin pack).
I had a bad experience but I did say that was only one brand, and after posting that last night I then found the unfortunate model I bought was indeed subject to some sort of recall in the UK a few years back (for battery problems). I never heard anything about it here in NZ but it's very possible mine came from a dud batch. I don't need any more right now but if I did, I might be inclined to give the long life ones another chance. As I said, your mileage may vary.
I replaced all mine with these Fire Smart and they are great plus do not false alarm randomly like previous one below: