Hi, I need your help to try and find a power bank for an upcoming Ultra Marathon event in the arctic next month (Ice Ultra – Beyond the Ultimate). Ideally it needs to have enough power for 5 days worth of charging for 3 devices (Phone, Watch and Headtorch) If there isnt a power bank that can hold enough charge, is there the option of another power bank to charge it back up ? The other issue is the temperature which will be as low as -40c and so they need to be able to withstand that or an insulation device to put them in.
Any info from someone who has experienced this would be excellent! Thank you in advance, look forward to hearing from you.