I've had bad luck with NiteRider lights becoming non-functional in an unreasonably short amount of time….

I rely on an array of lights rather than just two. On the front I have a Blackburn Flea (USB rechargeable) that I usually have on flash, a L&M (200 lumen) Stella mounted on my helmet and my newest acquisition is actually a flashlight - it's a Nightcore EA4 (550 lumen on high - 860 on max, but it won't stay on max for long periods to prevent overheating) - it's got a nice flat spot that works quite well for mounting on your handlebar with a big O-ring - I haven't tried it on my helmet yet. It might be too heavy. At $80 it's considerably cheaper than most bike specific bright lights.

On the rear I have a red Blackburn Flea that I keep on my messenger bag and mounted on my bike I have a Dinotte - here's what they say….. If you thought there isn’t a tail light that could ever be bright enough, think again and don’t say we didn’t warn you. The world’s first bicycle tail light to project a beam on the road. A light this bright encourages motorists to slow down and move out of your path when passing you. Just when you thought you couldn’t find a bright enough tail light, we created the product for you. (Batteries not included.) MSRP $129.00 U.S.D.

I can attest to this - I notice when the batteries are getting low because cars start coming closer again… people really and truly do not tailgate me when I'm using this light - I love it. I also use some spoke lights for a bit of side visibility.