A true ULer will greet this post with scorn – if you’re totally committed to reducing your packweight unnecessary electronics such as eBook readers or even cameras should stay at home. However, many lightweight backpackers (myself included) enjoy taking a couple of electronic devices into the outdoors, and the absence of trailside power outlets means that your devices are going to need charging occasionally.
Standard energy sources aren’t particularly useful to the backpacker – releasing the stored energy in coal, oil and biomass isn’t that practical, and until wind turbine manufacturers start fitting auxiliary sockets on the side of the towers or Colin manages to perfect his head-mounted personal turbine, wind power isn’t an option.
This leaves three real choices: a portable, lightweight source of stored electrical energy in the form of off-the-shelf household batteries, solar and kinetic energy conversion.
Batteries are almost cheating, relying on a fixed energy supply to charge the cells then offering a hassle-free, reasonably lightweight and reliable energy source. Available from many small village shops worldwide, this is the obvious choice for reliable power. But there are disadvantages – once discharged they become useless weight, carried until they can be disposed of appropriately or recharged. For the backpacker undertaking a trip with frequent resupply opportunities and/or a ‘bounce box’ this isn’t too big a deal, discharged batteries can be simply sent home to be replaced with a fresh set, and disposable batteries recycled or thrown away by the irresponsible.
I’ve made use of a couple of battery holders to charge my smartphone on long walks – a generic battery extender as shown above which takes 4 AA batteries and weighs 35g (without batteries) and the more refined iGo Emergency Charger which offers splitters, a choice of tips and so on for the same weight and 2 AA batteries. The Joy of Standardised Connectors is that by purchasing the former, any device that requires a charging supply of 1A @ 5VDC can use the same charger. One cable, one charger, several devices (and lots of batteries).
Solar chargers have improved in recent years, no doubt aided by the rise in affordable consumer photovoltaic (PV) cells to supply the housing market – though they’re still not that good in overcast Scotland. The Freeloader Pico shown above weighs 49g, and takes a good 2 days to fully charge when strapped to the top of a backpack (though you need to buy a separate silicon ‘skin’ to make that feasible). Whilst not an amazingly efficient solar charger, the Pico includes an internal rechargeable battery which requires a USB standard input (1A @ 5V yada yada), and can output the same via the USB socket on the right above. Whilst it takes a while to charge via the photovoltaic panel, by charging the internal battery at home (or even via one of the battery charger mentioned above) the PV panel will keep the battery nicely topped up even with minimal sunlight. There are bigger PV panels available that strap to bike panniers or even the top of a rucksack, but in order to preserve the barest shred of UL dignity I’ll not talk about them too much….
Kinetic energy makes sense, doesn’t it? Backpackers are expending energy to walk, so a device that could turn some of that movement into electrical energy would be perfect. Such a device does exist, in the form of the titanium nPower PEG but until these are available to purchase again and my review sample arrives I can’t confirm or repute their impressive claims. Rain or shine, fast or slow, as long as you’re moving the PEG should charge the internal battery and offer similar functionality to the Pico above. It is over 300g though.
So, for the time being we’re stuck with slightly less high-tech solutions such as the Maplin Wind Up Eco Charger above. It’s 95g and a bit silly, but you can’t deny the green credentials! No internal battery, a slightly rough winding action and unpleasant noise don’t make it my preferred choice, but in an emergency I suppose it’ll do the job. Oh, and it has a USB port under the grey flap above of course. Best of all, in common with all the products featured, it’s available for under £20.