Friday, January 16, 2004

Universal travel charging with laptop or USB hub: Cellphone, iPod, Palm, camera etc?

From: (John Faughnan)
Newsgroups: alt.cellular.sprintpcs,comp.sys.mac.hardware.misc,
Subject: Universal travel charging with laptop or USB hub:
Cellphone, iPod, Palm, camera etc?
Message-ID: <>

I think the USB cable standard is becoming the de facto universal
standard for charging LiOn batteries. I can charge my Tungsten E via
USB cable connected to a laptop or a powered USB hub. I recently
bought a lightweight adapter for $20 that claims to charge my Spring
Samsung cell phone via USB. The standard iPod will not recharge via
USB (needs firewire), but the new iPod-mini WILL (another advantage to
the mini for travelers!). I don't know of any digital cameras that
recharge via the USB connector but if they don't yet exist they will

Zip-Linq [1] makes very lightweight and portable USB cables that can
also work as data sync cables for a Tungsten E, and are used with some
portable travel mice. (They are not USB 2.0 cables and would not be a
good choice for iPod sync even if they had the right connector). This
cable, which uses a mini-USB connector will work with some digital
camera. Because of the business market, it's also possible to find
very compact and lightweight powered USB hubs with well made power

I think we're seeing an interesting example of convergence. For years
geek travelers, who carry a melance of chargers and cables, have
yearned for a simple solution. Magnetic induction charging solutions
have seemed close at hand, but never quite made it.

Maybe now the market, in a curious fashion resembling natural
selection in action, has converged on a standard.

A lightweight powered USB hub, itself with a lightweight and efficient
transformer designed for travel, can (in theory) charge at least 4
connected peripherals -- as long as they use this "USB standard"
charging approach. Many of the peripherals: iPod, cellphone, PDA,
camera may further use the same cable (USB 2.0 with standard connector
and mini-USB connector -- see [1]) for data synchronization --
eliminating another set of cables.

If one travels with a computer the internal USB ports may suffice for
2-4 devices depending on the computer. In that case a passive USB hub,
like the one I carry in my laptop's PCMCIA slot, the laptop and its
power adaptor, and a small number of very compact USB cables can
replace a mess of cabling and chargers/transformers.

Best of all, there are no new intellectual property issues here. Costs
are also very low.

USB charging is slow, but most of us sleep sometime. A good time to
recharge all devices.

I'm going to warily test out the phone USB charging adapter. Since the
phone I use (Samsung) wasn't designed to charge with this adapter I'm
running a risk, but I expect other phones will be designed to work
this way.

Anyone else have comments and experiences to share with regard to USB
device charging? I'm particularly interested in experiences with cell
phones, digital cameras (if any), the new mini-iPods and passive hubs.

addenda: eForcity sells a "universal USB charger"

This is a very nice wall adaptor. Not expensive. I'm going to try combining it with a passive hub to see if I can charge multiple devices all at once. eForcity has a number of quite interesting products along this line, including iPod chargers.

meta: jfaughnan, jgfaughnan, charger, adaptor, adapter, power adaptor,
power adapter, converter, convertor, USB, mini-B, USB sync,
synchronization, HotSync, laptop, portability, travel, cellular,
mobile phone, sprint, Samsung, portability, efficiency, convergence,
transformer, AC/DC, wall wart


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