Grab a cheap LED strip from a thrift store, tape it to a bike frame or a sturdy stick, and plug it into a battery pack you can grab off the back of a flashlight. Just clip the strip so the wiring hides in the handlebars, use duct tape to keep it from whipping around, and boom—a makeshift headlamp that’ll still work if the original charger fails. If you’re really desperate, bolt a spare car headlight into a modified tripod and use the old wiring; the extra weight will keep it from flying off when you’re sprinting. Remember, the key is keeping everything glued and protected—if it looks like a DIY disaster, you’re already halfway to a reliable light.