I just got in a commuter bike badged "Pegasus" it appears to have been made to for the European market. It has a Shimano dynamo and came stock with headlight and taillight. The front bearings are frozen and the wires from the dynamo have been pulled out. I found a youtube showing how to disassemble the hub. I wanted to test the lights before I tear into the hub and bearings. How can I simulate the output of the dynamo to test the lights. Can I just hook a 9V or 12V battery to test? Thanks!