Tenergy'xa09V NIMH Rechargeable Batteries,'xa0200mAh Low Self-Discharge'xa0Square Battery
Xa0200Mah Low Self Discharge Xa0Square Battery For Smoke Alarm/Detector (2 Pcs)
Results of our analysis:
We analyzed 55,953 reviews for 88 products in the 9V Batteries category.
We then analyzed 19 reviews for this product. Of these, 5 reviews were recent.
100% of reviews were positive.
Final Score:

8.32 out of 10, based on these factors:
Common Questions
What is the current output of the battery?
I think it's like 8.4 volts, but worked fine in my first alert smoke detectors.
How do these batteries compare to the regular 9volt batteries?
I use them in a dog collar that is a very tight fit and they work perfectly, do not charge before using.
Do the batteries work in the Kingman spyder?
The manufacturer recommends the use of alkaline batteries, not rechargeable batteries.
I bought 8 of them and used MaximalPower FC999, but it doesn't hold the charge, is this really good for smoke detector?
The batteries work well and you should make sure your smoke detector has a low battery charge.
The positive terminal broke off, but the reviews are a few years old, has it been fixed?
I have been using these for a long time and have not had any problems with them. I'd recommend them.