Although I just ordered an RTL515. I like to keep my lights steady (anecdotally a solid light in my peripheral vision triggers motion sensing, while a flashing one doesn't when I drive - and I project this experience of one to an entire driving population ) and in night mode (PWM modulated, not really flashing) my RTL510 runs out and disconnects after about 6-6.5 hours. I'll just bring an extra light in the saddle bag and swap.