Re: (very very urgent) Cannot charge N900
 

Excellent solution, well done! ;)

I only had a few minutes for this using a public WiFi hotspot while passing through the airport. What seemed like good idea at the time doesn't seem so brilliant now that I had a bit more time to think about it. You are lucky your battery survived the ordeal. The USB charger provides quite hard 5V while the battery requires a current supply with variable voltage up to about 4.2V. The only reason nothing serious happened is most likely because the supply wasn't that hard after all and the voltage dropped but I imagine the current was a bit higher than 1.2A - maybe even up to 2A. Worse still, that arrangement has no sense of how charged the battery is and will pump current into it until you switch it off. Doing that regularly is really asking for trouble.

Please note that my suggestion of using a camera charger is different because that has the protection circuit built in. So does the N900 but by connecting the USB wires directly to the battery terminals you have bypassed it. It might have worked in an emergency but please do not do it regularly.

Re: (very very urgent) Cannot charge N900
 

Well, it's indeed a poor solution. I had no other possibility of charging so I did it like that for about 10 days. And the battery died... Pressing the power button does nothing, there's even no lit up diod. When I try to charge it in my replacement N900, the diod lits yellow and dies after half a second.

I measured current, and it shows 3.99 V. What's interesting, even when I connected the voltometer to slots "+" and "0", the current value stayed the same.

Could it be a result of some short circuit?

Re: Cannot charge N900
 

Most likely the controller chip in the battery died. I would expect the battery to get very hot first before the battery itself dies. Either way it is unusable now, time to get a new one - and a stand-alone charger as per one of the previous posts.

Re: Cannot charge N900
 

And what could be the cause of the controller chip's death? I didn't notice the battery to be really hot... Only the charger was warm (or maybe hot)

Re: (very very urgent) Cannot charge N900
 

Lol :)

Off-topic: I have a laptop with a german keyboard, another with an US keyboard. My work PC has a swiss keyboard. I have 3 N900s, one with a german keyboard, another spanish and another polish (which, luckily, is like US).

Sometimes I really really hate computers and modern technology in general.