I use a 18v lithium ion Makita battery plugged into an old gutted out charger with LED lights on my Trike Choppa, has lasted very well, and I always have a back-up since it's the same one for my tools.
If I were you I'd add a battery and light (maybe a 6" bar) to the Banshee, and leave the factory ones too.
Maybe try new lenses for your factory lights. While not the best, I've never thought they were THAT bad.