Nokia uses the MicroUSB charging standard, which requires the charger to identify itself as a charger by shrorting the datapins together. The included cable is a datacable, which does not modify the signals at all. If the charger itself does not comply to the usb chargin standard, the n900 wont charge.

There was another thread here about external battery packs, where people had modified usb extension coords to make n900 think the other device is a charger. Might be risky if used improperly.

So the solution is to buy a MicroUSB charging cable? How does that differ from any of the data cable I have at home (besides the data pins being shorted together).

Today I purchased a Energizer XP2000

Initially I had some trouble getting it to charge the n900, the trick here was the XP2000 has a check/on button, it appears to only activate charging for a brief time if nothing is connected.

If I connect the n900 without pressing this button, I get nothing, if I press the button after connecting, I get nothing.

I have to press the button and connect the microusb to the n900 within a 1-2 second window, but after doing so it seems to charge normally.

Perhaps a similar process is needed to get the n900 to pick up on whatever charger you may be using?

I'm just using a DC power plug that has a USB plug. Plugging in the USB cable that comes with the N900 and plugging it onto the DC powerplug charger does nothing.

i wich i seen this thread last week, i just ordered couple of usb chargers
can anyone point me to orginal nokia car charger then?

It wouldn't differ. Except I'd leave them unsorted towards the charger, and shorted towards the device, if you know what I mean. You can't buy them, nobody makes such a thing. I'd buy something that comes with MicroUSB output out of the box, and return it if it doesn't work.

Doesn't work

Guys

I don't have all the details at my fingertips right now but it is not as simple as you think. When a USB device connects to a computer, it negotiates with the host to set the proper current.

There is a USB standard specification for how to implement a "dumb" charger, I think that it requires the D+ / D- lines to be shorted together or connected by a certain resistance. The N900 expects either to talk to a USB host to set current or it expects to connect to a properly configured "dumb" charger. The problem occurs when the "dumb" charger does not implement its USB interface according to the spec. Most likely the Apple charger does not implement the spec correctly. But I too have a mishmash of USB charging devices and some work, some do not with the N900.

i am no electrical engineer but i have an idea of modifying one of the old nokia charger.. i would like to cut away the pin adapter and put a usb port there.. any advice?