Just like any other battery, Ring batteries will go bad over time. The amount of time that they last will depend on a number of factors, including how often they're used and what temperature they're stored at.
Ring recommends that you replace your batteries every 6-12 months to ensure optimal performance. If you live in a cold climate, you may need to replace them more frequently as the cold can shorten the life of batteries.
If your Ring battery isn't lasting as long as it used to, there are a few things you can do to try and extend its life. First, make sure that you're only using fresh batteries - if they've been sitting in a drawer for awhile, they may be already be past their prime. Second, try storing your Ring (and its batteries) in a warm place - this will help prevent the cold from prematurely killing the battery. Finally, if all else fails, consider investing in a backup battery pack so you never have to go without your Ring!