# I need to charge my laptop while on a tour through the americas. Is there any way i can hit 40 watts using my bike?

I don't have a massive budget for a sweet solar panel. So i am curious to see if there is any way i can get the kinetic energy of my tires to capture enough power to at least charge my batter while i ride.
Small, lite simple & robust are all important factors. Any ideas?

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8 years ago
you probably don't need the full 40watts (0.05hp)

you can probably get by with using 20W (0.027hp)

unless the laptop is constantly on, you won't need the full 40w
okiave (author)  Sandisk1duo8 years ago
Cool thank mans I think i hear you.
So the laptop will still charge @ 20w but
will deplete faster than if the battery was
charged w/ 40w.

hungsoftware4 years ago
I instaled four Tung-Lin bicycle dynamos on my bike (two on each wheel). Connnected them in parallel to up the Amp. The Tung-Lin generator is the only bike generator I have found that have the right voltage and Amp for this purpose. It is rated at 12V and 0.5 Amp, so in theory, with four in parallel you get 12V and 2 Amp. However in practice, you get about 12V and 1 Amp pedaling at about 15km/hr. This is because it is hard to pedal fast enough to generate 24Watts of power. Note: You have to use four full wave rectifiers to convert the output of each dynamo into DC. Also you will need rectifier diodes to keep the current going from the dynamo into the battery and not the other way around. With this method I can fully charge my laptop battery in 7 to 8 hours.

You also need to buy a stand-alone laptop battery charger that is specifically designed for your laptop. You will not be able to charge your laptop while it is powered on. Also it is more efficient to charge it outside of the laptop - that's why the stand-alone laptop battery charger.

Here is the link to the Tung-Lin dynamo at Amazon:
http://www.amazon.com/Bike-Bicycle-Dynamo-Generator-12V/dp/B000OBWMGK/ref=pd_rhf_gw_p_t_3_YMNJ

Another way is to buy a foldable solar array. I used the Brunton 26 Watt Foldable Solar Array. Then I made a "top" to attach the solar array to so I can charge while biking. This method is very expensive.

Here is thelink to the Brunton Array:
http://www.amazon.com/Brunton-Watt-Foldable-Solar-Array/dp/B000GEFFBO/ref=pd_rhf_gw_p_t_3_QX1B

A third method is very complicated is to build a single bike dynamo using a motor. Here I found the "Hacker A50-16L Brushless Outrunner RC Motor" work very well.

Here is the link to the Hacker motor:
http://www.amazon.com/Hacker-A50-16L-Brushless-Outrunner-Motor/dp/B000U7ZW2E/ref=pd_rhf_gw_p_t_3_PDTG

What you need to keep in mind is: The charging rate depends more on the indiviual pedaling abillity than the dynamo. In other word, how much power can your body generate? and how long can you mantain it will determine how fast you can charge your battery. For example if your laptop battery need at least 20Watts then the dynamo you build must at least be capable of generating 20Watts and your pedaling must at least be able to generate even more (due to loss) and maintaining it for several hours.
lemonie8 years ago
I think of what would work and think of: rechargeable battery which you put power into by engaging a generator on downhills and braking. You'd build a charger to run from the battery. Pedalling the 40W might amount to hard work.

L
okiave (author)  lemonie8 years ago
holy smokes man you got a rad engineering mind.
I want you to be part of my tribe. I have an incredible
imagination but you take things to nest level.

8 years ago
The other level was fitting a rear axle-stand, then static-pedalling the 40W while not on the road, which you could still do as well. But I preferred the idea of recovering the energy you put in as opposed to wasting it in the brakes (which would last a bit longer too)

L
Re-design8 years ago
Just hit every Starbucks you see and charge there.  Most restaurants, coffee shops, libraries etc. will let you plug in a charger to top off your laptop battery.

It's going to be hard enough to make the distance without the added drag of a generator.  They really are hard to turn when putting out much power.
okiave (author)  Re-design8 years ago
@seandogue & @Re-design probably right.
I just need to be more practical about how I am
gonna do my deal.

Jack A Lopez8 years ago
This might seem unrelated, but if your trip through the Americas involves a border crossing (via bike, plane, car, whatever) into the Former United States, you should be aware that the border agents will probably try to seize and/or break your laptop.

See:
http://www.boingboing.net/2008/02/07/tsa-confiscating-lap.html
http://www.theregister.co.uk/2008/08/01/us_customs_laptop_seizures/

Obviously the best thing to do would be to avoid travel to the FUS if possible.  If you have to travel to the FUS, you should maybe do some more research on the best way to smuggle in your laptop and/or your data.
8 years ago
I've carried my laptop into and out of Mexico back to my home in the US several times and never even had to turn it on.  No problems with carrying it or my cell phone.
8 years ago
Ditto. There are horror stories, but they get news coverage precisely because they are unusual. (Something that happens frequently is not news.)
8 years ago
Yeah. I guess you're right.  I mean as long as the infrequent horror stories always happens to someone else, it's no big deal.
okiave (author)  Jack A Lopez8 years ago
@orksecurity @Jack a Lopez this is exactly what we need to talk about.
Not so much in a hysterical manner as the media would, but rather
in a collected calm manner with evidence. I love the web for this reason.
Granted these smaller realities are hard to find but eventually they float
to the top w/ enough conversation.
8 years ago

But even if they're only harassing a small number of people in this manner, it still doesn't make it right.

okiave (author)  Jack A Lopez8 years ago
Agreed.
I have been racial profiled a
number of times. I dont hold it against
all law enforcement but it certainly puts
a big damper on my relation with the people
who are doing their "job".

okiave (author)  Re-design8 years ago
I wont be coming back on bike.
Although this does bring up a few questions.
Maybe i'll just upload to AWS and call it good.
okiave (author)  Jack A Lopez8 years ago
haha thanks man I hear ya. Actually I live in AK and
am leaving the USA.
I too hate the direction our government is being run.
We have to change it. We are too divided.