Re: Solution: N900 Charging from dumb power sources
 

http://talk.maemo.org/showthread.php?t=36922&page=5

This page about half way down there is a guide for modding a standard USB cable to fool the N900 into charging from it. Pretty basic stuff if you have a soldering iron and a pair of wire cutters. Essentially the same as the OP but in cable form. You can buy like 10 min to micro adapter cables for 3 bucks from amazon and mod them keeping one everywhere you go, USB to micro USB cables are everywhere nowdays so I chose that as my option.

Re: Solution: N900 Charging from dumb power sources
 

Just as a sidenote, the charger for HTC HD2 works with the N900.

Re: Solution: N900 Charging from dumb power sources
 

Another off the shelve solution that does not involve soldering is the iGo USB Charging Cable coupled with the A97 power tip. Works with every USB source that I tried. It looks like it does the shortening of the data pins only on the tip side, so you can even use it to charge from a PC without messing its USB bus.

Re: Solution: N900 Charging from dumb power sources
 

As i've already written in another thread: The spec does not say to shorten them. Instead the spec says that you are supposed to connect them via 200 ohms. The n900 may work fine when shortening them, but shortening something always means that some significant power may flow over this short circuit. Using 200ohms instead is safe for any hardware as the current over the resistor is limited to 3.3V/200Ohms = 17mA.

These resistors cost nothing and may protect that hardware, so they are really a good investment.

Re: Solution: N900 Charging from dumb power sources
 

I had some USB adapters for car power points (http://catalog.belkin.com/IWCatProdu...duct_Id=489423) that I could not get to work with USB cables. So I picked up a cable to modify as suggested in this thread. Before I did that I needed to get something off the phone. But when I tried to use the cable as a data connection, it didn't work, it just charged. But based on the comments here about after doing the mod it would only be useful for a charge, I decided to retry these cables on my belkin plugs. For whatever reason, they worked without modification. I can only assume that they are manufactured this way. Anyway, the cables I used can be found here (http://www.bestbuy.com/site/Rocketfi...&st=rocketfish usb&cp=1&lp=3)

Re: Solution: N900 Charging from dumb power sources
 

Have you tested this? If so can you try using just the A97 tip and any USB to microUSB cable?

Re: Solution: N900 Charging from dumb power sources
 

I have the Seidio Micro/USB charging cable (for Palm Pre) which works with no mods.
Comes with the data connectors looped.

http://www.seidioonline.com/product-p/cbuptr800.htm

Re: Solution: N900 Charging from dumb power sources
 

I am a big fan of retractable cables and my existing USB-to-microUSB sync cable didn't work. So I have found I perfect solution for me - dual-head sync+charge retractable cable (black head for sync/charge, red is modified for charge only):

http://www.seidioonline.com/product-p/cbuymcr2.htm

Just verified it works with N900, although they say only works with Palms, Blackberries and Droids - I guess it just follows the spec...

May not be the cheapest solution, but universal - my BT headset does not require microUSB cable mods, so I now can charge N900 and BT from a battery backup using the single cable!

http://www.cyberguys.com/images/deta.../p35678a-1.jpg

Re: Solution: N900 Charging from dumb power sources
 

Found this while cruising the ThinkGeek clearance sale:

http://www.thinkgeek.com/clearance/b43f/

That could be a solution for those (like myself) that already have a kit of portable USB batteries and universal (pre-standard) charging cables. < $10 is a nice price point, too :)

Re: Solution: N900 Charging from dumb power sources
 

I looked at that too, but when I emailed the manufacturer (Boxwave) to find out if it was a standard extension cable with the data pins shorted I got some crazy answer that it has "a special circuit within the adapter" that "alters the signals coming out of the charger". Since there are no "signals" coming out of the charger, I suspect he had no idea what he was talking about. Has anybody tried this and can verify that it works?