Advance OpenStreetMap surveying with GTA04? / compass

[Alexander Lehner]

Mayeul, respect for the tour that you planned.

I'm an OSM'ler as well and know a lot of alpine 'freaks' which are not 
related to OSM at all - so this journey seems a lovely marriage between 
both projects, but...

How do you want satisfy power consumption of the device(s) that you will 
need?

Actually you require a 230V line every night to charge a bunch 
of batteries. Devices like GTA0x last about 3-4 hours GPS tracking, 
Garmin Etrex or similair perhaps twice as long. Cellphones last long in 
standby or for only making pictures or voicenotes, but with GPS apps 
they're running about the same 3-4 hours.

Low temperature will drastically reduce battery capacity or performance.

I was investigating a lot in charging ideas, but there's nothing suitable 
for such a case. You either need a huge pack of batteries, or a huge 
amount of accus and chargers and power suppliers.

For example: a bycicle dynamo delivers enough energy at about 20 km/h to 
keep the GTA0x alive in GPS tracking mode. A solar cell delivers enough 
energy to keep a GTA0x in 'sleep mode' alive.
Exchange GTA0x against any other mobile phone.

So how would you solve the energy issue?

A.