great battery for the money. Used in my smoke alarms as a hard wire back up.

I bought these for smoke/CO alarm ... and they works. I can not evaluate. I do change those every year regardless.

Gentlemen, Received this item along with other one and they arrived one day before promised. Thank you !

Have yet to see how long they last but poor design. Plastic piece needs to be removed in order for them to work at all. (Most people wouldn't even see the piece that needs removed)

These Ultralife batteries have dropped in price, it seems to me, in recent years. I have found good luck with them in all my smoke detectors, garage keypad door opener, and moisture detectors that I have in various places around the home. However, when I ordered these Battery Junction's website had this distinction between Ultralife batteries with the 'J' designation and said some are made more for outdoor use (the so-called jacketed ones) versus the FP version. This page is where it is stated: http://www.batteryjunction.com/ultralife-2018.html. I no longer see any distinction in the size and exterior appearance between THIS battery and the U9VLJPX (retail card) catalogue item. When I opened this foil packed battery and the bubble/card packed battery both had the identical number -- U9VL-J-P -- on each battery. There is a 5-cent difference in price on BJ's website but their descriptions a couple weeks ago linked you to the two different items based on your particular application or use. My point is that I SEE NO DIFFERENCE! Buy the cheaper of the two if you're shopping. *** Since I ordered these a couple weeks ago, it appears the BJ has removed the distinction between the J version and the FP version that used to be there. *** Ultralife no longer advertises that their batteries last 10 years. They say they'll last UP to 10 years and that is primarily how long their SHELF life is -- not their use in an appliance. These are still a good deal, a better battery than the alkalines, and most of the batteries in my detectors last a couple years or longer. I date all of them and I guess I don't open up the ones that have lasted a very long time. Maybe some ARE lasting longer than that and I just haven't had to change them.