Cycling UK Forum

Yes a Uniross Globetrotter battery charger weighs a little over 100g and has fittings for the major types of electric sockets in the world.
One charger and 8 spare batteries weigh the same as the excess weight of the best dynamohubs AND cost a lot less.

It will also charge up your AAA batteries for backlights, headtorches and MP3 players.

It's not fair to totally dismiss solar power. A small charger (like not much bigger than the batteries) will be useless, but it does not need to be huge. This one was sized for my laptop, not AAs, so smaller would do you. Here is mine.

http://mm0hai.net/blog/2012/12/14/First ... arger.html

The panel cost 33GBP. You then need to work out how to charge the batteries though.

If what you want is power, simplicity, and low weight, and you are moving most days, it is probably best to use mains. If you want an electronics project, like the idea of being self sufficient, or intend to live in mid nowhere for a while, solar is good. Especially for living somewhere, when you are not peddling. That is why I did this.

anm wrote:It's not fair to totally dismiss solar power.

It is if you look at the commonly suggested solar options like the Freeloader.

To be viable, you need a large enough area of cells to possibly cause packing problems. Something A5 size at the very least, bigger if you are in the UK or northwards, or hope to charge whilst riding or after the ride.

I generally just take enough spare AAs despite also using a dynohub for lighting. Lithium AAs cost, but they are half the weight of rechargeables and last longer.

There's an advert for a device on p 80 of the current CTC "Cycle" mag (Feb/March) for a thing called a "rider mount" which connects to a dynamo (bottle or hub) and can bused to directly recharge devices and presumably batteries.
website is ridermount.com
no experience of this however just passing it on, sounds interesting if it works AND is reliable.

if you have AA cells with (say) 2500mAh capacity you might think that (say) 3V @ 500mA (i.e. 1.5W) for 5 hours would be enough to recharge them. Unfortunately it doesn't work like that. You might more volts, more amps, and more time than that, by the time the intrinsic efficiency of the circuits and the cells is accounted for.

But surely a 3W source ought to be enough? Well, maybe. So I quite fancy the chances of charging such batteries using a hub generator and the right circuits in a day's ride.

What about solar panels? Well in bright sunlight, favourably angled, you can have an 8"x8" panel that will generate 3W. But realistically, if it is strapped on the back of your bike in temperate climes, you would be lucky to get 1W out of it on average, even on a reasonably sunny day. So for solar power you might need more area than that, and good weather.

There may well be products out there that do a little better than I have indicated, but they won't do a lot better than that, not today.

I hope that helps to frame any choices.

cheers

Like a few on here, I question the need for anything more elaborate than a battery charger.

My Etrex20 will I think get about 3 days cycling (of 8 hours each) from a single pair of rechargaeble AAs. I can recharge 4 AAs in an hour in a simple charger - am aware that such fast charging is maybe not favoured by purists/is the ideal way to do it, but how hard is realistically going to be to get some friendly soul to let you plug your charger in for an hour while you have a couple of coffees, drinks, small meal?

Portland wrote:Like a few on here, I question the need for anything more elaborate than a battery charger.

What about those of us who don't wish to carry a separate GPS unit with us? I use my phone quite successfully for navigating while touring and it obviously doesn't accept AA batteries.

Portland wrote:My Etrex20 will I think get about 3 days cycling (of 8 hours each) from a single pair of rechargaeble AAs. I can recharge 4 AAs in an hour in a simple charger - am aware that such fast charging is maybe not favoured by purists/is the ideal way to do it, but how hard is realistically going to be to get some friendly soul to let you plug your charger in for an hour while you have a couple of coffees, drinks, small meal?

While I agree that it's generally not hard to get someone to charge something for you many people, myself included, would like to do so without necessarily relying on that support.

Personally I take a load of spare rechargeable phone batteries with me and use a wall charger as shown below. I would however prefer to have a hub dynamo system and not have to do any external charging at restaurants, campsites etc.

Portland wrote:Like a few on here, I question the need for anything more elaborate than a battery charger.

My Etrex20 will I think get about 3 days cycling (of 8 hours each) from a single pair of rechargaeble AAs. I can recharge 4 AAs in an hour in a simple charger - am aware that such fast charging is maybe not favoured by purists/is the ideal way to do it, but how hard is realistically going to be to get some friendly soul to let you plug your charger in for an hour while you have a couple of coffees, drinks, small meal?

I agree entirely and despite possessing the equipment to charge AA batteries from a dynamohub, I have never resorted to using it while on my travels. I have only used it for experimentation and fun.
It generally saves weight and work to carry spare batteries and a nice Uniross Globetrotter battery charger which weighs in at the grand total of 100g. Up to 4 days I can survive on the two AA batteries in my GPS and the two AA batteries in my rear light.

However, that wasnt the question asked and we do try to give the information that people ask for.
While subtly slipping in what they really should have asked for.

My vote would be for a PowerMonkey charger which will not only charge a couple of AA batteries but comes with a kit of interchangeable tips which you can use for phones etc as well.

For a short trip you might be able to take a power pack which might recharge a pair of AAs four times (figure plucked out of thin air).

andymiller wrote:My vote would be for a PowerMonkey charger which will not only charge a couple of AA batteries

I've never understood why people recommend carrying a battery to charge AA batteries from.
Surely it's easier just to take spare AAs, which are at least instant use with no wait for charging.

I've just had a brilliant idea: a solar cell could be integrated into a cycling jacket. Like all my best ideas, someone got there first:

http://www.extremetech.com/computing/14 ... to-clothes
http://www.thesolarguide.com/solar-powe ... thing.aspx

I think somewhere (maybe it was on here) someone posted a piece about the wonders of/encroaching madness of cycle touring which included a bit on obsessing about ever more clever ways of harnessing solar power when pretty much the whole world, even those bits untouched by the British Empire, has electricity for recharging tiddly cells.

Maybe some kind soul can post it here - twas very funny I thought.

I really want to know where the OP is going. This place where there is no mains electic available? Where is it?

Is there anywhere that we can cycle which doesnt have restaurants, hotels and B&B?

Nobody questions why we should wish to take tents, mats and bags, cooking equipment and fuel on those grounds.

bigjim wrote:I really want to know where the OP is going. This place where there is no mains electic available? Where is it?

Let's suppose cycle camping in Scotland, with a fair amount of wild camping thrown in.

Charging at a campsite:
1) leaving stuff charging unattended in the toilet block can be prone to pilferage.
2) charging in reception means that you are subject to reception opening times, and if it's a small site where the man comes round and collects the fee there may be no reception.

Charging in cafes:
1) Scotland is sparsely populated and cafes are thin on the ground in many areas
2) Sod's law says that the socket that's not in use for kettles, toasters etc is under the tables with a well settled party at it.
3) You need a fast 1h charger, which in general terms is bad for the batteries
4) I'd be worried about only remembering the charger when I was 5 miles down the road.