Charging backpack
Here’s how I put everything in place so I can charge my MacBook Pro and my Nokia cellphone while driving or riding my motorcycle without removing anything from inside my backpack. No modifications needed!
You’ll need:
- a backpack – mine’s a Samsonite, completely indestructible
- a (good) power inverter – I use an APC Travelpower – 75w
- a 3-way plug adapter
- the chargers you will be using (the cell phone charger is harder to remove from the backpack, as it stays with the inverter in the closed inner pouch)
- a cable to connect the 3-way plug adapter to the laptop charger (not pictured)
- some kind of tape to firmly connect the 3-way plug adapter and the inverter (not pictured)
Here is how you put everything together:
- Study the internal layout of your backpack, find where the inverter should go (preferably a zippered pouch), and some open pouches for the cellphone and the laptop charger.
- Attach the 3-way plug adapter to the inverter using some tape, so it doesn’t come loose with the all the movement, connect the cellphone charger and the cable that will connect to the laptop charger, in the flattest configuration possible. Wind the excess cable around the 3-way plug so the ends of the cables can just reach the right places.
- Put the inverter/plug adapter/cellphone charger in the enclosed pouch, routing the cables to where the zipper ends.
- Put the laptop charger in place (where it’s easily removed, so you can use it “normally”), and find the place for the cellphone. Make sure that the laptop charger cable can reach your laptop (which you should stow in a way to make the charging port accessible).
- That’s all! When you’re driving (or riding your motorcycle, if you have a 12v socket where you store your backpack – a future modification I’m doing on my Yamaha Majesty), you just have to fish the inverter cable out to connect it to a 12v socket, and all your hardware will get the juice it deserves with no fuss, and no entangled cables! If you have a bluetooth handsfree car kit/headset, you can even use your phone without even opening the backpack.
Important note: make sure the inverter has enough power to charge everything – in this particular case, although my inverter is rated for 75w, and the MacBook Pro charger is 85w, it will not consume that much if it’s just charging a sleeping/turned off computer, leaving more than enough margin for the ±5w cellphone charger.
[...] December 10th, 2006 Pedro at matsu has put together a great set of instructions on how to set up a backpack to be a mobile charger for laptops and cell phones. Very useful if you spend a lot of time mobile. Posted by Doug Filed in Blogging, Technology, Mobile, Tips, Hardware [...]
Nifty!
Is there any concern about excess heat building up and melting/frying anything? I know some chargers generate a lot of heat.
Also, it’s a shame that you have to convert DC current (from the 12v socket) to AC current (the inverter) just to be able to convert it back to DC again (the batteries in your laptop and cell phone). There must be a better way, but it probably involves a great deal of hacking and voltage regulating.
Thanks!
Ben,
That’s one of the reasons I stated that you should get a good inverter, and basically should only use it to charge (and not operate) the laptop/cellphone/anything else, as the chargers don’t work as hard as doing both (charging and operating) at the same time.
The problem is that you’re going to need some inverter of some kind most of the time, as a lot of laptops use DC current above 12 volts. But the DC -> AC -> DC conversion is indeed unnecessary.
Bahhh…
You know better ways than this…
Probably you have lighter chargers for those things, and is cheaper to buy one instead of buying an inverter. Also, what the point of converting to 220v and then back to 12v or whatever your stuff need. You loose power up and down again. And that power is lall ost in to heat, things could be warm in winter, but in summer it will be hotter…
The idea is neat, but is best to just stay in the 12 volt range. Remember that you travel with 220v in you pack, and water or any other “problem” could carry trouble. If things began sparkling you will become a Yamaha movable Christmas tree.
Think again, mate!
cheers
some companies are starting to offer inverters in a form factor that will fit a cup holder (300W, 400W peak).
many/most backpacks have an external pocket to accomodate a water bottle.
add soem velcro strapping to keep tidiness, and you can keep your internal space in the backpack (you just might need to give up the water)
Great idea, I think now you can using this for extend battery refill
This is such a fantastic idea, I am trying to recreate what you have done – BUT – I cannot find the 3 way adapter *anywhere* – HELP – where did you get it ?
Very cool post! If I was still in a job where I had to be highly mobile, I would be making one of these today.