Advance OpenStreetMap surveying with GTA04? / batteries

Mayeul Kauffmann mayeul.kauffmann at
Mon Mar 19 02:20:35 CET 2012

Thanks for the questions and the comments!
We will sleep every night in a managed alpine hut or hotel (depending on
place). I did the "hike and sleep in a tent" 15 years ago and know I
will not resist 80 days now! Last Summer I crossed the Dolomites with a
8 kg backpack. This year I will carry less of friends' stuff and more of
high tech; this gives room for another battery.
Last October we did a 3-week mountainbike tour (Sardinia) in similar
conditions (hotels...). A set of 2 LR6 batteries lasted typically 7 to
16 hours depending on device.
Issue in mountain is that sometimes there is no public 220V power plug.
Experience last Summer (8 days in Dolomites) told us that sometimes the
hut keeper has a power plug even if this is not public; given that we
contribute to free & libre maps, we hope in these case to have access
and plan to ask by email well in advance if power is available and if we
can use it (we already have the full email list).

I'm more afraid of 12 V plugs but let's hope they will be rare.
I might bring my old Garmin EtrexH as a backup. With a very small added
weight, I get 2 days of hike. For LR6, I use Eneloop batteries (sorry to
advertise this), which do not discharge as Ni-MH do and have better
resistance to cold (typically an entire snow-shoes hiking day around 0°
Several people asked me "what about solar cells?" and I was not sure. So
your comment "A solar cell delivers enough energy to keep a GTA0x in
'sleep mode' alive" is very precious for us, thanks!!

Sure, we will try to reduce consumption and, yes, I'm not sure the above
will be enough. We'll try to make a 2-3 days test in May!


Le dimanche 18 mars 2012 à 23:49 +0100, Alexander Lehner a écrit :
> 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.

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