Interesting. I'm assuming the drivers are probably Meanwell 60-48Ds (pretty standard for diy lights) which can handle 24-48 volts, one more quick question, were they flickering when they were on a low percentage then not flickering when you turned them up? The Cree white Xp-g's have a FV of 2.9 @ 350mA so with them dimmed down below 350mA maybe it wasn't within what the driver can do.