hi,
ive searched and found lots of charging problems, but nothing like this.

The phone is 1.5 years old, for about a year now ive been experiencing occasional (few times a month) lapses in charging where the phone would report that it is charging when pluged into the wall socket in the evening, but in the morning would report low battery after unplugging.
I sent the phone for repairs half a year ago, to have the factory (unsurprisingly) just reflash ist. the problem presists and has become more prevelant; occuring about once a week.

Any ideas?

My guess is that something is wrong.

You should get a separate charger and some extra batteries. Whatever is causing it, a separate charger is preferable anyway, and quite inexpensive.

Yes, your port is about to fall out, mine did the same 2 weeks ago, started like yours, wall chargers didn't work, then usb became intermittent then it fell out :@

Mine was 17 months old, i needed a phone that day, had been saving my upgrade credit for something decent to replace N900 so now have had my hand forced with a HTC desire Z, not a patch on the N900

Thabks for the replies!

hmm,
I disagree that the problem is the usbport, since the phone claims to charge throughout the period it is connected to the charger (checked with batterygraph). furthermore the phone has never actually died while connected, so maby its taking power just not actually charging.
I also have trouble beleiving its the charger since it is a dumb machine that just feeds current, and whenever i notice that charging had failed in the morning, simply plugging in the charger again solves the problem. I'll try it non the less.

The symptoms are unpredictable, it feels like every time I plug in the charger god flips a coin to see if the phone will actually charge with a chance of ~1/10.

The problem presists after getting a new battery.

Honestly, sounds very familiar, i didn't check the battery graph, but when you plug in using the wall charger it used different charging circuits to the usb cable.
The wall charger has some kind of resitor setup to regulate volatage and stop the current when full. could be something to do with that?

What you describe, is EXACTLY what happened to mine, i thought it couldn't be the port like you are doing, I am now waiting for a battery charger and spare bat, they cost about £4 all in including delivery from BestBuy, I'd save yourself the wait and buy some piece of mind at that price

are you using the OEM charger?

I am using the oem.
if the port were at fault, and could not "notice" that the data lines are shorted, the phone would not claim to charge would it? or would atleast pop the "computer is supplying less power then phone is consuming" or what ever that was.
I do occasionally tranfere large files over usb; if the port were not stable I would have experienced dropped transferes.

and i maintain the fact that the phone's log shows it charged six hours straight. if the charger had somehow stopped charging it it would show.

not battery, not charger, then could be software.

i have seen some weird graphs with the battery monitor on my phone (once time, one of the lines on the graph went backwards in time - i.e. towards the left - and then turned around and moved forward again).

if the battery is not at fault, and the charger is not at fault then it is something in between the two that is not routing the charge to the battery. i am not familiar with the circuitry between them. you may want to ask dr_frost_dk @ http://talk.maemo.org/showthread.php...d+battery+test . he seems well versed with battery technology and the n900's battery circuitry.

Try a different battery? Oh, I see you did.

I recently had to clean the connectors in my USB port with contact cleaner to have it work reliably.

Frank

I can only say with all these charging issue threads lately that i really like my charging system .

Sorry i can't be of any help here