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What's your travel power supply record?


I often rant here about the need for better universal power supply technology. And there is some progress. On a recent trip to Europe, I was astounded how much we took in the way of power supply gear. I am curious at what the record is for readers here. I suggested we have a contest at a recent gathering. I had six supplies, and did not win.

Here's what the two of us had on the German trip in terms of devices. There were slightly fewer supplies, due to the fact several devices charged from USB, which could be generated by laptops or dedicated wall-warts.

  • My laptop, with power supply. (Universal, able to run from plane, car or any voltage)
  • Her laptop, with power supply.
  • My unlocked GSM phone, which though mini-USB needs its dedicated charger, so that was brought
  • My CDMA phone, functioning has a PDA, charges from mini-USB
  • Her unlocked GSM phone, plus motorola charger
  • Her CDMA Treo, as a PDA, with dedicated charger
  • My Logger GPS, charges from mini-USB
  • My old bluetooth GPS, because I had just bought the logger, charges from mini-USB
  • My Canon EOS 40D, with plug in battery charger. 4 batteries.
  • Her Canon mini camera, with different plug in battery charger. 2 batteries.
  • Canon flash units, with NiMH AA batteries, with charger and power supply for charger.
  • Special device, with 12v power supply.
  • MP3 player and charger
  • Bluetooth headset, charges from same Motorola charger. Today we would have two!
  • External laptop battery for 12 hour flight, charges from laptop charger
  • Electric shaver -- did not bring charger as battery will last trip.
  • 4 adapters for Euro plugs, and one 3-way extension cord. One adapter has USB power out!
  • An additional USB wall-wart, for a total of 3 USB wall-warts, plus the computers.
  • Cigarette lighter to USB adapter to power devices in car.

That's the gear that will plug into a wall. There was more electronic gear, including USB memory sticks, flash cards, external wi-fi antennal, headsets and I've probably forgotten a few things. I will agree one or two things are exceptional here. I didn't need two GPSs, but since my logger GPS was so new I wanted to be sure I could do what I needed. I actually did end up using both though. If we were not users of CDMA phones, and had unlocked GSM phones as our regular phone/PDAs, we could have just brought those and inserted the German SIM cards we bought into those. Our PDAs take flash cards and could be MP3 players for a more limited choice of music.

But yes, you really do need all those chargers. It's not uncommon when we are on the road to arrive at the hotel, plug in the chargers and go right to sleep, and head out quickly in the morning. If you want to recharge all devices, you need a dedicated charger for each. Some USB devices can be charged from the laptop, though often I don't want to keep the laptop running during the night, and that's the only way to have it generate power on USB. I used to have a double charger for camera batteries that would charge two batteries during the night, but they no longer provide that. There were times in the past when it turned out to be important. I now have a mobile charger that can run off 12v, allowing car charging.

Motorola's RAZR has a horribly annoying feature. It won't charge from generic USB power! It uses mini-USB but will only charge from its dedicated charger, or from a computer USB, if the computer has had Motorola's phone tools (which you must buy) installed. It is possible to trick it, starting it on the computer, and then quickly switching to a wall-wart USB source. How shortsighted.

If going in the car, I bring a 12v to USB converter and that allows charging and operation in the car of phones, GPSs and other devices. This can save you from the "we must charge everything while we sleep" rule.

My phone's GPS now works, but I still bring the logger GPS because the phone GPS can't log (which I want for photo geotagging) because the GPS goes off if it goes to sleep, and can't do much else if it's being a bluetooth GPS to the laptop -- which is how I do navigation software.

My bluetooth headset now charges on mini-USB (yay!) but Kathryn's charges off micro-USB. Fortunately these do not need charging each night.

There's other stuff I didn't bring. You should see my Burning Man electronics kit, it's several times more stuff than this. You may find me with a backup disk, a voltage converter for a 12v device, a backup of that device, a USB webcam, a 2nd laptop power supply (for really long trips, so I can keep one in the bag and have one plugged in,) a 3-fer adapter for car cigarette lighter, a radar detector for long road trips, two FRS walkie-takies (using NiMH batteries so I can use the same battery charger) if we're going places without cell service such as cruise ships or remote locations.

Pretty ridiculous. Some day I hope to just bring a much smaller number of master chargers that can charge multiple devices. Today I could bring a powered USB hub for all the USB devices, and that would help. Down the road, I would just want to expect the hotel to have a multiple device charger -- powered USB hubs cost $20 and should be standard in hotel rooms, like hair dryers.

I also think powered USB hubs should be standard in cars. The Car dash, and several other locations in the car, should have USB jacks or even retractable mini-USB cords you can pull out of the dash. And it should have a USB B input, so that if I hook my laptop into that, the laptop can talk to the various devices. Actually, the car itself should be one of the devices the laptop sees, so the laptop can get all dashboard information and more advanced diagnostic information from the car computer. The car should have a GPS built in which the laptop can draw on, but until then I should be able to talk to my own GPS connected to one of those USB sockets. In addition, the radio should appear as a USB device, allowing the laptop to use the stereo as a set of speakers, or control the radio, or other fun things. This should perhaps be subject of another posting in the future.

So what's your record for power supplies and chargers?


That is an incredible array of technology that you have taken with you. I don't think I can top it. But you're right, with a laptop, phone, Ipod and sat-nav - it all adds up. I like your idea of making cars have USB. What would be cool is that the cars have USB and power outlets powered by a fold away Solar Panel (that sits plush on the roof) that you can take up to the hotel with you and charge everything that way.

Think I may go to Dragon's Den with that....

First of all, you need a fair bit of power here for all this charging, and you mostly need it at night. It's silly to take it to the hotel (where you usually only are at night) and you may not even have a sun facing window anyway. Only on-grid solar makes sense; off-grid solar is generally silly. Even on cars.

Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT and some coworkers have recently announced a new electrode that makes the classic high-school chemistry experiment about splitting water into hydrogen and oxygen using electrolysis work a whole lot better. See the MIT press release at

If you remember what happened in that classroom experiment, the H2 and O2 bubbles accumulated very slowly, and used a lot of power along the way. Using Nocera's easy-to-make electrodes the process is much faster and more efficient; the videos show bubbles looking like they're coming from an aquarium aeration stone.

This means that using distributed rooftop home solar could be a realistic option, with H2 as the storage medium, as Nocera describes. H2 now has potential viability as a transportation fuel, since distribution networks for water and electricity are already in place and we don't have to worry about distribution from centralized H2 plants that use steam reformation from natural gas methane and its CO2 byproducts.

This story got a lot of press. The research is real but the press interpretation is entirely bogus. This technology has almost nothing to do with solar. Zip, nada. It's a better technique for electrolysis, which uses electricity (from any source, from coal burning to solar) to generate hydrogen and oxygen. Worse, the research is about improving the oxygen generation, though there are paths from this to improving the hydrogen generation.

Better hydrogen generation would be a good power storage technology, but it has very little to do with solar. The main connection it might have to solar would be for off-grid solar panels that need a way to store their electricity; this could help them store it in hydrogen. The oxygen is generally not kept though pure oxygen does have its uses since it does take energy to get that.

On-grid, you don't need storage tech for solar. Solar gives its power during the peak power usage parts of the day. Storage is the last thing we need for that -- we want to use it.

As noted, this is OK for off-grid, including those who want to put a solar panel on a car, if it is a more effective method of storage than batteries or other methods. Storing hydrogen presents its own problems, of course.

What was the "special device"?

This brings up something I've wondered for a while. Is it time to consider a standard
domestic (house- or building-wide) DC power system? Fifty years ago, most of the items
plugged into the wall in a typical home or office actually needed AC power and used it directly (electric typewriters, incandescent lamps, hair dryers...). But now, especially assuming LED lighting takes off, the vast majority of the things we plug into the wall only use AC to generate DC with a transformer. Why not have
a single transformer for the house that generates, say, +/-15V, and distributes it through the walls to
standard DC outlets? No more wall warts, chargers, or heavy power supplies.

In an older blog post. It's generally a good idea, but you can only ship a much more limited amount of wattage if you use a lower voltage (DC or AC) and would need to put in extra wiring. (Perhaps not, it's possible to combine DC and AC on the same wire and pull them out in some cases.)

Some solar powered houses do keep both a DC and AC wiring set. A good voltage to do the DC at is 48 volts but very little equipment uses that. It is the voltage of Power over Ethernet.

Brad, great blog - After carrying so much, I'm wondering if you managed to make space for two spare AA cell batteries for your mistress's vibrator on this little European 'sojourn'? Although if you like things a little 'Al-Fresco' a solar-powered pocket-rocket would be a great invention.

I love the PowerMonkey which has a solar option too. Its range of adapters means you can easily work out a way to get power to most things you have. Plus its standalone. Its no good relying on power outlets in airports and train stations - or in my case - at sea.
Its hard to get hold of PowerMonkeys in the USA but well worthwhile (Ebay is worth a look). It holds its power very well and gives me two power-ups for my power hungry G3 iPhone when I am at sea. Its been a real life saver and allowed me to top up when other sources of power have let me down. Add to that they are quite cute looking. Plus you have a range of adaptor tips (PSP, Nokia, etc) and worry-free mains power attachments for USA, Europe, UK and Asia - just travel with what what you need - and it only weighs 60g and the power reservoir lasts for 6mths. I travel with two which means you can be generous when someone is caught short.

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