FWIW, the following site has beam shots for both, with all the usual caveats about interpreting these: http://www.bikeforums.net/showthread...e-Expilion-700

Suggest rather than get a spare battery, get a second entire light, perhaps a 600 for <$100 which uses the same battery. Then you have two batteries, can charge the batteries independently, can run both lights, one on high the other on flash then switch to extend run time and increase conspicuity, one on the bars and one on the helmet, etc...