I use a 4-battery aux pack with a plug that matches the Garmin. Works like a charm and it doesn't drive a reboot when you plug it in. Pls allow me to disagree with you. I'll bet you that anyone....ANYONE... who can ride a century in 7 - 8 hours can ride any of the rides I did. It's all in having a bike that's comfortable, having a bit of nutrition, knowing how to pace and being mentally-prepared. Someone actually asked for my advice today....and I posted some comments today here.