I think it might just be doable with powerbanks. For example if you can afford 5 Nitecore Summit 20000 power banks (or borrow them somehow) you’ll have 337Wh of “rated energy” (i.e. at the power bank’s output) at your disposal. They’ll weigh about 1.5kg and should be enough to fully recharge your headlamp (2350mAh*3.7V=8.7Wh) about 34 times (assuming an optimistic 90% charging efficiency).

Most lithium ion batteries perform poorly below 0°C. The Nitecore Summit has an integrated heater to heat itself when it is that cold.

It would help if you could reduce your power consumption further. For example a Petzl Actic Core headlamp at its lowest setting is rated for 100h of runtime on a 4.6Wh battery. If you can find your way at that lowest setting it would make your charging situation a lot easier.

I think it might just be doable with powerbanks. For example if you can afford 5 Nitecore Summit 20000 power banks (or borrow them somehow) you’ll have 337Wh of “rated energy” (i.e. at the power bank’s output) at your disposal. They’ll weigh about 1.5kg and should be enough to fully recharge your headlamp (2350mAh*3.7V=8.7Wh) about 34 times (assuming an optimistic 90% charging efficiency).

Most lithium ion batteries perform poorly below 0°C. The Nitecore Summit has an integrated heater to heat itself when it is that cold.

It would help if you could reduce your power consumption further. For example a Petzl Actic Core headlamp at its lowest setting is rated for 100h of runtime using its 4.6Wh battery. If you can find your way at that lowest setting it would make your charging situation a lot easier.