I ride the road at night with a 900 and 2X 230's. On unlit country roads the 900 comes on, about town the 230's are on and at dusk/dawn one 230 to make me visible. I've just fitted another 900 to my helmet, more for off road but I'll use it for the commute too. The mulitple lights may seem a bit overkill or battery hungry but it gives me plenty back up and they all use the same type battery.