But if you're looking for portable USB power, I just picked up a Zagg Sparq, slightly larger than the palm of your hand. Here's a picture of the two devices for a size comparison:

http://mym0ry.smugmug.com/Other/Misc...1726&k=4ZgVQSRhttp://mym0ry.smugmug.com/Other/Misc...01554752-M.jpg

http://www.zagg.com/accessories/zaggsparq-c.php

It'll hold enough charge to fully top up an iPhone battery from empty 4 times.

Do you know what the charge time on the zagg is - one problem with charging from USB is that they take bloody ages (at least my contour HD does, haven't bought a stills camera yet)

The Zagg *is* a USB charger, so it won't be any faster than how you're charging via USB right now. Just that it's portable (won't need an electrical outlet - at least until the Zagg runs out of juice) and it's smaller than a motorcycle battery (which is I think what you were originally asking for).

The Zagg outputs 2000mA.

Sorry, what I meant is what is the charging time for the Zagg, rather than from it!

Ah, gotcha.

I just got it, so I haven't drained it completely yet, but from what I've read online, they say about 6 hours to charge from empty to full.

And you can charge your USB devices while the Zagg is plugged into the wall recharging as well, so everything is recharging at the same time.

Henry,

Firstly, forgive my ignorance! Are you concerned about the battery getting dodgy and this interfering with the running of the bike? I won't pretend to know much about electrics (it's all the devil's business as far as I'm concerned) but my Enfield has been sat in the garage best part of three years and the battery is comletely screwed. At least half of the acid has evaporated and it holds no charge. However, I have a Boyer Bransden Powerbox fitted in place of the standard regulator/rectifier and the bike starts and runs fine.

Matt :)

PS - Wanna buy an Enfield?

Hi Henry - consider something from Power Traveller... if all you're doing is charging a camera and phone then something like this will be ideal

https://powertraveller.com/iwantsome...nkey-explorer/

The solar charger it comes with takes 8 hours to charge, but you can just leave it in your tank bag map case during the days riding and take it back up to about 75% from empty over the full day. 50% if it's overcast. But the good thing is it does 4 complete (when full) charges of my iPhone and 8 for my camera battery, 6 for the DSLR.

With just the monkey (not using the 12v socket) I can do 5 days on the road without needing a power socket - at which point I can plug that in and get it back up to 100% in 20 mins - and then I have another few days free of the grid.

If that's not go enough juice consider this one

https://powertraveller.com/iwantsome...r/minigorilla/

It runs up to a full 19v and has a higher output so charges things much much faster - including the monkey several times over. It can run my laptop from empty to 50% and takes 16 hours to charge (to full) with the solar panel sold separately or with the larger gorilla pad in a shorter time.

https://powertraveller.com/iwantsome.../solargorilla/

In practice I find that gorilla solar panel too large on the bike so rely on power points every 5 or so days and the small solar panel. The mini gorilla unit takes 45 mins - 1 hour to fully charge so it's a case of doing it over lunch / dinner rather than over a coffee for the monkey.

The monkey will charge over a 12v socket - the mini gorilla won't.

I run off those two devices (and the small solar unit):

* Android Phone
* Casio compact camera
* VERY old iPod 2nd Gen
* Panasonic G1 DSLR
* Sony eReader
* Canon HD Camcorder
* Apple MacBook (13")

If I run as normal I get 5 days between sockets, if I'm careful I get a week - and as the monkey can charge in an hour off the 12v socket I can keep running permanently if I need to on the smaller stuff. (I know you can't do this). The only thing I require the mini gorilla for is the camcorder and the macbook.

I did a brief write-up of the gear over on the blog here

Powering on | The London Biker

I must do a video of it at some point.

Matt (Cartney) - the bike doesn't need a battery but it would have some bonuses - so I'm weighing up the pros and cons....

Pros of no battery:
Simpler to build
Lighter bike
No battery to leak/dry up/die
Less tempted to take non-essential gadgets
Putting a high-tech Li battery on an essentially classic bike might be sacriligous?

Pros of battery:
Very easy to add 12v charging socket
Can run LED lights and decent HID Headlights
Could even splash out on a GPS and have it running all the time!

Matt (Cashmore)
Thanks for all the pointers, I'll check the links out - see my final choice at Ripley

Hi Henry,

Yes, makes sense. I did consider removing the battery from the Enfield for lightness (it needs all the help it can get!) but decided to keep it (or never got round to it really).

A lot of electronic gadgets you can do without or run on AAs. I'm sure there are one or two Digital cameras that run on AAs or AAAs, but it will limit your choices.

I see you considered a netbook - and they are fantastic - absolutely ideal for motorbike travel IMHO. Even a cheap one will do all you need in terms of writing a blog and editing pics. I use one, but I need it for writing when researching books. It would be tempting not to bother if I was travelling light and not writing. You could just take multiple SD cards and download your pix to Flickr or similar every time you come across an internet cafe.

What else do you need? A phone? Easily topped up with a USB charger at internet cafes or using a solar charger. I would imagine you can also use the SD card in a phone to store extra copies of your photos, although I haven't looked into this.

Just out of interest, why is it you can't charge devices off a 12v system running off an alternator with no battery?

Matt :)

To be honest Matt it's because I know naff all about electronics (as opposed to electrics, which I have just about got my head around). I have no idea whether or not the erratic voltage coming off a magneto would fry the battery in a netbook or overcook a modern camera battery. If just wiring into the main loom would be an option that would be great!

Like I said, I'm no expert, and I may be putting my electronics at risk! But, I have a cigarette lighter adapter which I wired directly to the positive and negative terminals of my XT. I know the voltage across the battery terminals depends on whether the engine is running and driving the alternator. I can't remember what the difference is, but it's a couple of volts perhaps between the engine on and the engine off. So that would suggest that the voltage is mainly dictated by the alternator, not the battery and also means I am getting a variable voltage at my cigarette lighter adapter. If I remember correctly this was the way the adapter was meant to be wired up and I didn't just assume (I do have a reasonably well developed assumption instinct) that it was to be wired up this way. This might suggest that you can charge off a battery-less system? I note that you are using a magneto of course, so I don't know what difference this would make. This is DC right? I'm guessing charging devices are set to run off AC and this might cause issues.

I'm just thinking aloud really. Like I said, its all the devils works to me.

Matt

PS - If anyone knows a good reason not to wire up a cigarette lighter adapter direct to the terminals of a battery, please let me know before I fry my netbook!

I think the problem could be caused by the voltage constantly going below 8 volts whenever you go to idle, which is the minimum operating voltage of some gadgetry. The magneto works just like an old fashioned bicycle dynamo, so when the engine's not running there is 0 volts, and it increases linearly with revs.

It might be that some or all chargers can handle it but I've been unsucessful in finding a definitive answer on the internet so far