What is the cheapest GPS unit with mapping and replaceable batteries (AA) that's worth looking at? That you can upload gpx files to of course.
I have no idea if it's the cheapest, or even current these days - but my Etrex 30 will do mapping,routing, backlit screen, for nearly all of PBP (four days) on 2xLithium AAs.
I've bought cheap battery packs from Tesco and other places but they don't seem to charge up fast and even hold their charge in some cases. Plus I've had phone plugged in to one overnight and it only half charged the phone. It was so slow. Not impressed.
The other question is whether good power packs are worth getting even solar cells. Or whether it's possible to get a mapping GPS for less than a good battery pack / solar cell system.
Any recommendations will be gratefully received.
Forget solar. It's too much faff small scale, and Sol isn't big enough (and if it were, we wouldn't be here).
Agreed. You're unlikely to keep the panel at the right angle, and you're going to want to cycle in the shade to keep cool and not burn, but your panel wants to be in the sun, etc... solar is ok if you're base camp style, but if you're on the move, lots of storage, or a dynamo.
Dynamo chargers might give you some benefit if you're (a) riding 200km, or (b) freewheeling off an Alp for three hours.
Assuming no losses in charging, if you ride for 10 hours, dedicate the full output of your 3W hub, through a USB-Werk, you're going to get 25Wh of energy, enough to charge 1/4 of the big anker pack linked below. Still enough to fully recharge some smart phones, but not quite enough for most, and you're not going to want to charge the phone direct, as you'll just shag the battery. Always charge a power pack, and then charge devices from the power pack.
Fboab and I play Ingress as well as cycle. This requires a LOT of phone power. Our experience - Don't skimp on battery packs, you pay your money, you takes your choice. We use big packs, and charge them whenever we can - from the Van, from the Pub, from the Charge Station at the campsite.
Our preferred packs of choice - Pretty much anything that has "Anker" on it, the bigger the better.
Agreed, the biggest you can get these days is
this one. I doubt they will make them much larger, because once you get over 100Wh, airplanes stop letting you take them.
A power pack will be more cost effective than a solar panel.
If you are travelling on the continent, this is a nice light high power output charger:
RAV 3 way 30W (sorry, couldn't find an amazon uk link for it).
Remember, not all usb cables are created equal, get good quality ones, consider if you want right angle as well for ease of fitting things in the right place. And don't be drawn by the idea of long cables, they tend to be too losy, and you don't charge as fast.
Pack your battery pack and charger and cable where they are easy to access. When you stop at a cafe, hunt the table with a nearby power socket. An hour of charging while you have lunch, with both ports of the anker above in use, should get you an additional 20Wh (about the same of 10 hours of charging of a dynamo hub...)
Finally, as a slightly left field suggestion, if simply tracking your journey is your main goal, I can highly recommend the
[strike]Delorme[/strike]Garmin Inreach Explorer+. 100h of battery life (in reality, nearer 75h), and because it's relaying via satellite, gives you a handy offsite backup of your travels... and allows family to not worry too much. It's very much not a cheap option, but I really love mine and I think they have a lot to recommend them.
J