This is a very broad question as so many things, such as temperature, or how long the batteries were on a shelf, can effect battery life. It is also very dependant on what brightness setting you chose to run your light. Using either standard new Energizer AA batteries or the fully charged Li-Ion battery, you can expect the following estimated times for continuous use (longer if intermittent use):
100 Lumen LED:
High – 8 hrs; Med – 20+ hrs; Low – 50+ hrs
Note: These are regulated times. You will see some lighting companies give both regulated and unregulated times. Unregulated battery life claims end only when there is a minimal but still visible sign of light emitting in a dark room. It is not a usable light. Our claims are based on a steady, consistent output.