Mountain electronic devices and keeping them powered up

One of the first things you notice as you get further away from civilisation (Kathmandu) is that the cost of charging devices becomes more expensive.  In Lukla recharging electronic devices is generally free but as soon as you hit Phakding, you pay around USD$3/hr.  Past that it goes to USD$5/hr.  Once at BC there should be a generator to charge your devices provided by your logistics company (covered within your costs), which usually run from late afternoon onwards.  Not the most environmentally friendly approach as it basically consumes fuel to operate.  This is why I look at a better alternative.

The devices I took with me (and what I should have left behind in Kathmandu)
This then raises the question of what is the best way to recharge your devices.  For my Everest+Lhotse (EL) expedition I took:
1) MacBook Air (MBA)*;
2) Smartphone (Sony Xperia Z Ultra);
3) SLR camera (Sony A7R+5 batteries);
4) Spare Nikon waterproof compact camera (AW100 +4 batteries);
5) Satellite phone (Isatphone);
6) Rechargeable headlamp (Black Diamond ReVolt); and
7) Rechargeable HAM radio
(from what I can remember).

That is a lot of stuff to take to Base Camp (BC)!

*In hindsight, I should have not taken the MBA to BC as it is not good to take it to that altitude.  The lower pressure air at that altitude significantly impacts a laptop's ability to cool, and it will heat up heaps...so make sure it does not get too warm/hot!  Take care with condensation as well.  If you do want to take a laptop then buy something cheap that you do not mind destroying.  I will not take my MBA on trails again.

Prioritise order of charging devices
Now, one has to consider how to recharge if you do not want to be paying by the hour all the way to BC.  Naturally the priority for charging is to charge the safety equipment and frequently used items that saves on batteries first (5, 7 and 6), followed by the things of less priority (3, 2 then 1).  Spare camera was not used and thus did not need to be charged (topped up if required).

How much daylight and maximising it
There is around 7-8hrs of good daylight for charging in Spring but if you are on the Everest trek route, then you need to be able to strap a panel of some sort onto your bag to take advantage of the available light.  I was using the Powertraveller Powermonkey Extreme 12V for this purpose.

When you stop trekking and arrive at a guest/tea house, or when in BC, this is when you can take out the big guns such as a foldable/rollable panel.  Hook it either to a battery storage or directly into the device.  I was using an Tactical 24W flexible panel with a car 12V socket, which I had purchased at a sale at 50% off...I should have bought two of them!  You ideally want to have a regulated power source charging your devices as you can damage your device by directly connecting to an unregulated solar panel.  Use at your own risk.

What I learnt (or knew beforehand)
Different devices require different power inputs.  One thing I was aware of, was that this setup alone would not be able to charge the MBA.  That MBA (and most Apple laptops) will require substantially more power, and consistent power.  I charged my MBA via the generator source at BC and used it infrequently along the trail to BC.

You need to look at what power your devices requires before you head out, and make sure you have all the right connectors.  Try to limit the number of different connectors and try to label them if you can.  It makes searching for the right combination a much easier exercise instead of rummaging through it.  Keep cables tidy and separate (tie them individually up with rubberbands).

All my devices were able to be charged perfectly with this setup.  That said, I did encounter a failure with the Powermonkey Extreme.  For some unknown reason the cable from the solar panel to the battery/controller failed to make contact properly.  I was not sure whether it was a battery controller issue, whether it was the non-USB small connector jack plug, or whether it was the battery/controller input jack socket that failed...I suspect that it was the input jack socket of the battery/controller.

This was a pain in the butt.  Lucky for my Tactical that gave me alternate power (and the BC generator).

The good thing is that the Australian Powertraveller distributor (Sea to Summit) covered it with a new replacement under warranty.  That is the type of service I would have expected from a good company like Sea to Summit.  That said, I may have been unlucky (as you know I am VERY UNLUCKY) with getting the problem in the first place, but it does shake my confidence in the product.  The device saw hardly any use at all before failure.  Powertraveller would sell thousands of these devices internationally so...pure bad luck on my part?  My confidence has been shaken and thus I will sell my replacement Powermonkey Extreme and I will get a chance to try something else :-).  A gadget freak like me always likes to try new things.

Having a battery pack makes like easier when you head to higher amps.  You can still charge your safety devices.  I also take spare camera batteries to higher camps, but to know that I have a lightweight battery storage at C1 or C2 is comforting (in a C3-C4 8,000m type mountain).

Where to next?
1) I will be keeping my Tactical panel as it is a gun when you need power!  Even when there is some cloud in the sky it is still able to capture the sun's energy.

2) I have been looking at the Voltaic Systems and Goal Zero options.  I am inclined to 'future-proof' by buying a more powerful system.  I can ensure that if I did take a cheap laptop to my next BC then I can still charge it without any issue, also accommodating any future power hungry devices.

i) I am leaning towards the more expensive Goal Zero (GZ) Sherpa 100 kit with inverter as it has stronger connectors and it can daisy-chain easily with the Tactical panel.  All I do is buy the GZ 8mm to 12V plug and I connect the Tactical to the GZ Nomad 20 panel, which in turn connects with the Sherpa 100.  This gives me solar panel power of 45W when I am stationary, and 20W when I attach it to a backpack when moving.  I can even fold the Nomad 20 down in size by one segment (lose 30% generation capacity or so) if it is too awkward to attach to different sized packs.

ii) Also, the choice of a GZ inverter provides flexibility with accommodating Apple laptops...as Apple has a habit of changing their proprietary connectors.  In the future, I don't need to go to eBay and buy another AUD$40 12V to MagSafe 2 adapter, or whatever new connector is released, when I can just use the power plug.  Only disadvantage with an inverter is that they are around 20% inefficient...but I can overcome this my the high power solar panel setup.  This would only apply to items being used on the laptop (MBA) whereas everything else would obtain efficient DC power from the other Sherpa 100 output ports.

If (when :)) I do buy it, I'll do a thorough review from the trail.  Give it a good testing.