Tourist in MSN: I am looking at a rugged phone with a large battery that can still be charged at temps near freezing. I intend to use the Bike Energy Harvester or the ladelux headlight from Schmidt to keep the phone that I use for navigation charged. I believe having Bluetooth and Wi-Fi off and just having the phone off when not needing the navigation on will be manageable. The other large user of power will be my tail flasher. In addition to the rugged phone I am going to purchase the Dinotte D6 The slow pulse setting lists operating time at 40 hours. The D6 has a USB C charging port on it. I will also carry a fast charge 18 watt cell phone charger. I was looking at the Voltaic solar panel setups. I am thinking a 10 watt Panel would be enough.