Lithium batteries have a life expectancy - either an expected shelf life or a maximum number of cycles before they are no longer functional. Things that decrease life expectancy are: deep discharging, frequency of use and storage temperature and charge state.

300 to 500 cycles are projected for most lithium batteries, with some higher end batteries rated for 1,000 cycles. My own choice for batteries was a capacity that only required charging once a week. Projecting that should give a life expectancy that should be almost identical for cycles and shelf life - about 5 years.

How do you estimate your own batteries will make out based on frequency of charge? Anything that needs recharging on a daily basis will probably need replacing after not much more than a year. Was battery replacement frequency and annual cost a consideration in your light purchase?