Yes, 5W is sufficient. It takes about a week to fully charge the Ring camera battery. If you have set your ring to record only motion events, this battery will never run out. At least, in my own 1-year experience, the battery reached 30% level only once, and that too when there was continuous rain and no sun for 7 straight days. If you record 24 hours of video footage, you may need a higher watt/voltage battery preferably a 12W one or above.