I've had to replace 2 batteries on the Magic Shine due to the connector going bad on me. Having said that I'll probably get another one since it's cheap.
Agreed Majic shine is the best and cheapest out there. I also had the female end of the connector go bad by disconnecting from the plug. However, I hacked it open and re soldered wires and taped it up. Works good now, but battery lasts for maybe 2 hours max also if its left on the side for a day i need to recharge it every time i do night riding.