Boyer Brandson has a Power Box that limits the headlight until after starting, it also works with their dreaded MkIII ignition, and allows the bike to start either with a low battery or No Battery... their headlight off option is the 00107 Power Box, and actually the fellow from the tech department at B-B stated that I didn't need that, and the 00108 Power Box would function just fine with either No Battery or a discharged battery for starting purposes on my 1996 Iron Barrel. I have the B-B MKIII ignition and it does fail to start with a battery low on voltage. I carry a mini jumper box with its own cable clamps,and that has saved me from getting a jump from another car or bike... Now, I had called them to enquire about the MKIV ignition box, and the tech said that if I used the Power Box 00108 then I wouldn't have any more starting problems with my MKIII ignition. I believe you can run without a battery, or, unplug the fuse if you want to continue using the battery (My choice) when using their Power Box, which replaces the regulator/rectifier on the Bullet Iron Barrel...