Ultralight Hike
So that you don’t run out of juice on the go there are various ways and means to charge your smartphone, GPS or similar devices while out and about.
In the following I will explain the advantages and disadvantages of various methods for charging devices on the go.
To be adequately supplied with power for electronic devices on the go there are various methods. The most common are power banks to charge the smartphone via USB. But even with these simple methods you are faced with an embarrassment of choices. There are thousands of models from hundreds of manufacturers that are difficult for the end user to compare. Among other things a power bank advertised with 10000 mAh does not necessarily have 10000 mAh. The battery cells vary in their performance from model to model. The capacity also decreases over the years of storage. Just as with every deep discharge. Then there is the electronics. Batteries only provide a voltage of 3.7 volts and these first have to be stepped up to 5V for USB. Here there are numerous different converters with an efficiency of 70-91 percent. But this also means that up to 30 percent power loss occurs here alone. Unfortunately the buyer cannot determine for individual models what efficiency the power bank converts the voltage with or what batch of the actual battery they got.
Therefore I will only refer here to the following combinations which have proven themselves for me for which purpose:
Miller ML-102
This charger fascinated me due to various advantages. For one the electronic converters are said to work very efficiently which means a high power yield for the batteries; for another the unprotected 18650 batteries can simply be swapped. This makes it possible to take exactly the number of batteries needed for a trip.
As a further advantage the unprotected 18650 batteries are relatively inexpensive. The difference between protected and unprotected batteries consists of a small electronic circuit in the batteries that prevents the batteries from being overcharged or deep discharged. With protected batteries this circuit is located in the batteries; with unprotected ones this circuit must be present both in the charger used and in the consumer device.
Since the ML-102 serves as charger and consumer device and has the circuit integrated this combination is safe in and of itself despite unprotected batteries.
I use the charger with 1-4 Panasonic batteries (depending on tour length and power consumption). So I have between 3600 mAh and 14400 mAh available at 36 g for the charger + 50 g per battery.
On longer trips (from a week) with moderate power requirements I take my 20100 mAh power bank, since there is no need to swap batteries. This also makes daily charging of the smartphone possible for 5-6 days.
If the power requirement is even higher like for example due to the GoPro camera in Sweden and Norway this year my choice fell on a solar panel with 13 watts.
This solar panel at a good 300 g (after trimming unnecessary ballast) was able to charge the devices day after day. In southern regions panels with lower output could also get the job done.
For the future I will take another look at the Kraftwerk fuel cell to see whether this product is suitable for an even higher energy yield per weight.
Stay tuned,
kImpi!
