The title might sound like it’s hypothetical but it is the actual question I have been pondering over the last few weeks.
While I can’t reveal the full route we have planned, it’s a remote ride that involves little chance for electrical power. Limited tarmac means little infrastructure. For this trip we have to ensure we keep a GPS track of our route and we need to have power to navigate on vague tracks and paths. Paper maps don’t seem to be below 1:3,000,000 scale!!
What electronics to take?
1. GPS units
The GPS track data is really important for this trip, for reasons that will become clear later! We will use Lezyne Super GPS to record the ride, with a 14hr battery life and real world reports saying they exceed this we think it’s a good option to record GPX ride data but also hopefully heart rate data on some days. 
The Lezyne Super GPS does have basic mapping function on it but we will preserve battery and leave it alone recording the track only.
We have the fully loaded Lezyne Super GPS pack with cadence and heart rate sensors. We probably won’t use the cadence sensor I don’t think but we will use the heart rate sensor to see out of interest what happens as the altitude changes. It will only be used when battery availability allows as we aren’t sure how much of a drain it will be with the Bluetooth connection.
We will take two Garmin E-Trex 30 units to share between 3 of us. These are for navigating and will use open source mapping. While the screens are small and the unit fiddly to use and look like an old school Nokia phones, they take 2 AA batteries and last for over 2 days GPS use. I have dropped mine 4 times riding at 30mph and it still works!
It is easy to carry spare AA batteries or to charge rechargeable AA batteries.
Garmin E-Trex30
2. Phone
For the rare occasion we get 4G or WIFI on the trip we’ll take our standard android smartphone. This also allows us to upload direct from the Lezyne Super GPS to back up data.
We have downloaded the excellent Soviet Military Maps App on the phone. This is old paper maps scanned into an APP and geo-tagged for free. These are out of date a bit and often based on aerial flight charts from cold war era charts but are the best resource I have found when riding in the ‘Stans. Roads will be changed but contours are handy for navigation.
3. Ipod shuffle
Small, light, plays music and doesn’t matter if goes flat!
4. DSLR Camera
The beauty of DSLRs are that they don’t need a screen to use and therefore don’t use much power, 3 batteries could easily last for the entire trip. I will have a Canon 6D with 17-40mm lens. I will take a charger with a custom bought super short euro plug cable to save an adaptor weight and bulk of too much cable.
I will also take my old Go Pro for a bit of fun footage and to get timelapse shots while riding.
5. Lights
Black diamond AAA battery head torch. These things get brighter each time I lose one and buy a new version. We don’t intend to ride in the night so this is enough for emergency’s. A simple LED rear light from Smart will be carried for long days.
Power source while bikepacking
I have previously used various methods to charge electronic kit, but my favourite approach is to just not use electronic devices much – paper maps tend to stay charged much longer! This trip is different and we need a power solution for venturing into one of the remotest parts of the planet.
1.Solar
I previously used Goal Zero Nomad 7 Solar panels including a ride we did to Istanbul and these are often seen as the best out there, take a look here.
These work well and with panniers because they fit across the back nicely all day. With bikepacking bags the options for fitting at the right angle are more limited. They also very much all need direct sunlight to charge much. If we were to be crossing the Gobi desert this would offer enough sunlight to work well. However I sold mine because I don’t think that solar is the solution. To much bulk, faff and cloud cover! It was too unpredictable and too easy to move so that the angle to the sun was not quite enough to charge stuff. It required constant attention. But it is lightweight and relatively cheap compared to hubs. If you can survive without power every day in sunny climates then certainly an option.
2.Dynamo Hubs
This was the obvious route to take, getting a new wheel built with a hub dynamo seemed the best option at first.
The SON Deluxe is the classic dynamo hub. If you can afford it, the drag can be as low as 0.01% when off and 1.7% when. This hub would need to be on a lot of the time as it generates comparatively low output. It is not cheap either at about £250 for just the hub. The link above is the 12mm axle version I would have needed. To be honest it was the price which put me off these and the low output in return.
The Shimano range of dynamo hubs are solid performers and cheaper. The levels of drag are higher than the SON but still not much, at an average of about 25kph it is up to 7 watts compared to a quoted 4-5 watts for the SON. The Shimano DH 3N72A is a solid performer by all accounts and much cheaper. The impact on your speed is calculated as just under 3%. So if the charger is on nearly all day which it probably would be, in effect with the same effort you’ll travel 2.5km less each day per 100km. Over 3 weeks this would add up to a not insubstantial 50kms! THere are also questions over how efficient the hub is and reliability.
To go with any hub you will need an adaptor to regulate the output, then an interface for plugging in a battery to store charge for USB devices. The Busch & Muller E-Werk is a well respected system to regulate the output, it retails for £125. This still then needs a battery pack and USB socket which is another £50, the Tout Terrain Plug is a neat option that sits in the stem;
It all adds up in cost to buy a system you can totally trust (£500+) and in weight (400gm+). For just lights and maybe a phone, hubs are a good option for TCR and audax events, or even long tours where power demands are not so high. However for me on this trip they don’t seem to be the best option nor an affordable one where we need slightly more power and I’d rather not spend £500.
Here are a couple of interesting blogs about the impact of Hubs, there’s no exact science and I have assumed longer usage and at higher riding speeds, but they both conclude the noticeable impact is not much at all:
Dynamo friction
Another view on watts etc. lost
3. Large External Battery Pack
This is the option I have gone for. It is the cheapest, easiest and hopefully most reliable for my needs. The pack I have is the RavPower 22,000mah pack.
It weighs 412gms so isn’t that light and the picture shows it is not too small. However it will charge the Lezyne GPS about 15 times, our phone 8 times and the Go-Pro about 12 times. It takes 11 hours to charge up which is quite a while but better than many as it accepts input of 2.4a USB. The size and weight are comparatively very good and best in its class. It can be plugged in and charged over night when we stay indoors.
It charges 3 devices up to a total of 5.8a at a time so pretty impressive output!
The weight is actually about the same as the other power options when you factor in the solar/hub units and the battery storage/power regulators the solar and dynamo options still need.
This isn’t the best for charging lights etc. for all night riding and maybe the hub investment is the best way to go for longer RTW trips. However for the least impact on riding, most reliable and the best value it makes sense.
Essentially it should keep the vital kit we need charged. I will report back to see if it was a successful choice and how frequently we managed to charge it and charge devices up from it!