Powering/charging a laptop on the road?
 

I am going on a long trip round Spain next month and I am not going to be staying in hotels alas.

I was just wondering if there is a cheap way to charge and power a laptop (in this case a pretty low power Ibook g3) from the bike battery without spending an arm and a leg?

Its only a 125, so not the biggest capacity battery in the world ..

I figure I will just have to be sneaky and slip into hotels and public buildings and filch from a power socket etc.

But if there's some advise from those who know how to power my own device I'd be greatly interested to know ..

Cheers,

Harry

Here you go ....

In-Car DC Adapter Charger for Apple Mac iBook G4 G3 45W on eBay (end time 12-Feb-10 15:09:46 GMT)

No idea if they are any good, I use an Asus, but it is powered from the bike.

Oh thats brill! Thanks!

I understand DC-DC adpaters are far more efficient than inverters too ..

Cheers!

The laptops I have had, always had the possibility to charge from 12volt. If not available original, then you could buy an unoriginal.

If you only charge while riding, there should be sufficient current as the computer current is quite low.

Computers like the ASUS901 uses 12V so is easy to charge from the bike.

Silva has a solarpanel for charging anything that uses 12V

Silva Solar Ii-12vÂ*charger

http://www.sailgb.com/Thumbnail.aspx...man/solar2.jpg

For motocycle travel I don't think solar chargers are the way forward. Read the info on how long it takes to charge 2 AA batteries from an A5 sized pannel!

I do wish the laptops would move to an Asus EEEPC style plug-transformer rather than the separate 'power blocks', which are just too heavy in my opinion.

Hi Harry,

I installed a small 12V outlet in the dashboard which runs into my tankbag with a homemade extension wire. It comes straight from the battery with its own fuse. I chose to buy a $20 100W 12V/110V inverter because it gives me flexibility; one day I'll charge my netbook while riding, the other day I'll charge my camera batteries, PSP or cell phone. Yes, I am a geek, even on the road. All use the standard 100-240V adapters that come with the device rather then having to buy a bunch of specialized in-car power supplies. You may want to figure out how much juice your bike generates while riding before installing. I don't advise using this (or any) setup with the engine turned off; you will drain your battery quicker than you anticipate.

Good luck and have fun on the road!
Vincent

I second that. If you try and charge your laptop overnight from a 12v socket on the bike, you will almost surely have a flat battery in the morning.

I had a flattened my 10AH bike battery on a barge when it was just powering the GPS. I turned the ignition of the bike on and put the GPS unit in its cradle to record the track. Not much more than 24 hours later, both the GPS battery and the bike battery were dead.

I guess if the GPS used 6 watts (about half an amp) then I should have calculated (using very basic maths) that the 10 AmpHour bike battery would only power the GPS for 20 ish hours.

My CG 125 has a new sealed battery, but its only 6 ah/hr. :)

I have to power via a 12v hookup: ipaq for GPS, headlamp (35w always on), ibook (75w) and still find time to charge up a GPS receiver and 3 1200mah batteries for the camera and cam corder. Hehe.

Its going to be fun! I think I will be ok tho, the late model CG's have electric ignition so I am guessing they have slightly better alternators?

I'm seriously thinking about adding a manual switch for the headlight as that would free up a lot of juice ..

Could carry a 2nd battery I guess but thats 2kg's out of my meagre 12kg load allocation!

Damn stupid always on headlamps. I miss switches!

It's not your battery capacity that you need to worry about, it's the Stator output. You should be able to find a workshop manaul somewhere and this will teel you the power output.

Then you need to work out what your bike requires for normal opperation ( Don't worry about the cold crank output too much)

Once you have these, subtract the bikes requirements from the stator output and you have your power budget.

You can get away with oversubscribing the budget for short periods, but then you need to run the bike (properly, not just tick over) to replace lots charge.

You should aim to have a fully charged battery at the end of each day.

Well put one on then. It's not hard. You can switch if off while you are charging and then on again afterwards.

Only problem is the bike is still under warranty. Also I am pretty sure it would be a bone of contention with the insurer. Should be ok anyway, I'll just make sure I don't charge the laptop/accessories unless the bike is moving. The iPaq I am using for GPS uses sod all power so that ought to be fine ..

Charging laptops
 

Using a DC/DC converter on the move will be fine. It'll easily keep your laptop charged.

Don't use an inverter. The cheap ones don't give pure sine wave output and you'll seriously reduce your laptop battery life. More expensive inverters are OK but far to bulky for a bike. And they're extremely inefficient. 12vDC to 240vAC then back to DC through a transformer - you'll kill the bike battery.

Take a mains lead for topping up from cafe's hotels, etc but you may not need it.

Happy trails,

Jojo

The electronics in your normal 240v laptop power supply will make sure that even with a sawtooth output (which most cheap 240v DC-AC converters supply) your laptop battery will not be affected.
Only drawback in this setup is the substantial inefficiency DC-AC converters have. In order to produce a decent 240v AC current, it generates a huge amount of heat !
Not a problem if you're enroute to the North Cape, but a tad overdone in Saharan conditions.
Sadly most laptops nowadays (ACER, ASUS, DELL) use a 19volt, 4amp power supply.
Unless you have a 24v system in your car or bike, for the bigger laptops the 12vDC into 240Vac seems to be the only option.

Greetz,
Joey

btw @Jojo1 : a new battery after North Cape did cure the Disco's start-up problems , they replaced it under warranty, as it was just 7 months old !
:funmeteryes:

The Asus EEE series uses 12V so it can be run directly from the battery, at least while the engine is stopped.
Even laptops using 19V could be charged from 12V as there are dedicated chargers usin DC/DC converters to increase the voltage to 19V
Even cheaper DC/AC converters have efficiencies around 85% so the loss is not that big.
I have had problems with environment temperature though. A converter in my car was only designed to max 55 degree centigrade environmental temp. so it cut out lying in a car in the sun in summer.

Poul