Rayovac Ultra Pro Alkaline 9V Batteries, 12 Pack

I have a lot of smoke detectors in my house. One of them began chirping a few days back, reminding me it's time to refresh them all with fresh 9V backup batteries. So I bought two 8-packs of these Rayovac "Ultra Pros." I ordered them in early July, 2019, and each of the batteries I received were individually labeled "Feb 2023" so it's unlikely that these had been sitting for a long time in a warehouse losing charge. When I replace batteries in my smoke detectors, I always test the voltage of the new battery I'm about to put in to make sure it's working and reasonably fresh. I only needed 12 of the 16 batteries for my detectors but went ahead and tested all 16 of these for the heck of it. They would initially read 9.39 V or 9.40 V, but if I held the testing leads to them for another 30 seconds the reading would slowly climb up to 9.50 V. I've seen other alkaline 9V batteries that measure 9.55 V or slightly higher when fresh, but I was satisfied that these all reached 9.50 and that there were no duds among my order. Note that every year or two my homeowner's insurance mails me some 9V batteries bearing their own logo, and those ones seem to have about a 20% dud rate, no joke -- this is why I decided to buy name-brand ones for my smoke detectors as I need them to work and to last a decent length of time. It's also why I decided not to buy the AmazonBasics 9V batteries. I've had great luck with AmazonBasics AA and AAA rechargeables but the reviews of the AmazonBasics 9V alkalines left me with the impression that the quality control isn't all there. Enough said -- these seemed reasonably priced, fit my Kidde-brand smoke detectors, and based on the initial voltage readings they are fresh batteries that I hope to get 16 to 18 months out of before needing to replace them.

I realize they say to replace smoke detector batteries yearly but man they got expensive. Anyway. Bought these in 2022 and changed them out today. No issues in 4 smoke detectors for 2 years that are hardwired and battery is backup. I would say worth it compared to big box stores charging just about double.

I've been using these 6 pack Rayovac 9V for a few years now primarily in smoke detectors in multiple properties (hardwired with battery backup type). I've used in both BRK and Kidde/Firex brands--these batteries fit fine. I tried using the ~$9 each Lithium batteries made by Energizer? as they listed 10 year life--no way you will get 10 years--more like 4 years in a hardwired battery backup smoke alarm. I've tried alkaline Energizer, Duracell, and these Rayovac--I don't see any difference in longevity when used in smoke detectors. PS: smoke detector companies now make smoke detectors with built in/non replaceable 10 year battery--a bit more expensive (around $55 for hardwired versions from what I recall) which I have started using--yes, a bit pricey but if it eliminates one call for "it's chirping" from an aging relative at 3am scared its carbon monoxide or just can't sleep it is well worth it--time will tell how long these "10 year built in battery" smoke detectors actually last.

In the past I always rated Rayovac batteries with five stars because in addition that they are very good and reasonably priced batteries, they were also made in the USA. Since it is no longer the case, I lowered my rating to four stars.

These batteries are fine, by the way. No issues.

I use these 9 volts for my active pickups in my guitars and a lot of negative crap has been said about rayovac compared to Duracell and what's the other one oh yeah energizer but these rayovac 9 volts have lasted longer even the regular rayovac 9 volts I believe they're blue with a little bit of silver, blow away Duracell and Energizer combined. The regular rayovac 9 volts are just as good as these and for a few dollars cheaper

I always buy Rayovac batteries because they last and aren't as expensive as the bunny or the copper top. They fit my smoke detectors and last a long time. Nothing worse than those 3 am sporadic beeps before the 6 months is up. I don't get that with these so am pleased.

got these for the smoke detectors in the house and they work as advertised

5 out of 6 batteries had the right voltage, one of the new battery had a voltage less than 9 volts!

Only used one battery so far, but it's working well. Bought the 12 pack of 9 volts.

Needed some batteries urgently for the fire alarm in my house and got them delivered the next day. No issues until now. Good packaging and quick delivery.

That's all I know. First time I haven't owned this brand so I am hoping they have decent life. Seem like a good battery.

Buy in bulk, it's less expensive in the long run. Good quality batteries.