Let's face it, everyone sooner or later needs to have a few extra batteries around the house for electronics, remotes, etc. and of course no one wants to pay a fortune for them either. I especially pay particular attention to keeping my battery back ups for my clocks current as well as THE most important things that count, like my smoke alarms. Rayovac is probably the best battery you can find and for a 4 pack at this price, it was well worth it! I have 2 digital alarm clocks as well as 2 smoke alarms, so this is perfect. But, as the package recommends theses zinc chloride batteries are only for low drain device that use very little power over time. Like Alarm clock battery back ups and such. Now for a higher draining electronic that you get a lot of use out, you would use the heavy duty alkaline which lasts longer. However if you want to keep your clocks and smoke alarms properly backed up and ready to go when you need them, I recommend stopping by Big Lots and grabbing a pack of these. It'll definitely save you money!