[Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

Hello guys,

I have noticed a very very strange behavior with my N900 yesterday,
I'd like for a volunteer to try and reproduce it as I have managed to reproduce it but want a 2nd opinion.

1. Connect car charger to DC socket, Start engine or what ever you need to do in order to make the charger alive.
2. Connect N900, it should start charging.
3. Turn of the Engine or what ever you need to do to cut DC supply to the charger, But don't disconnect the charger from the DC socket.
4. My N900 still shows charging! but I know for sure that there is no DC cause the charger light is off.

If someone manages to recreate this, i'll know something is odd with the N900, if not, i'll grab a voltmeter and check the voltage of my car charger.

5. BTW, if you now disconnect the charger from the phone, it will stop "charging"
6. I have not actually left the phone there to see if it charges, it scares me, When I say charging in step 4, i mean the phone displays the charging animation.

So, Any thoughts?

Edit : When i'll have enough information i'll open a bug if needed.

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

same bug here.... but with wall charger....

plug charger into wall... connect n900 with charger... n900 say chargeing ... and now unplug charger from wall ... but leave the usb kable where it is... still says chargeng

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

I've seen the same behaviour. Thought it was residual power or something like that. Didn't leave it attached to find out.

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

probably some electricity left in the capacitors or similar. how long does the device think it is charged?

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

Longest iv'e left it in was 5 minutes, kept charging.
And I never seen this with nokia N86 with the same charger.

So I don't believe it's some capacitor (:

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

That also happened with my N86. Unplugging the power supply from the power outlet and the N86 still claims it is charged. I once left it to see, when it would stop and it kept saying charging for another like 30 seconds, then it stopped and displayed the message, that you please unplug the power supply.

I think this is pretty normal and not scary after all. A possible explanation could be some capacitors that are discharged slowly when unplugged from the power.

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

I'll try it again today. Just to make sure :)
I'll wait a couple of minutes.

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

hmm.... no i think


it only check voltage of the charger when it beginn to charge... and later then it only checks the D+ and D- wires wich are shorted at normal chargers.... when you unplug charger and leave usb connected the wires are still shorted and it thinks it is still charging...

dont know if it is true ... but this is m noob thinking^^

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

that could be reasonable explanation if the device thinks it is charging for minutes.

Re: [Possible Bug] N900 keeps charging with car charger even though charger DC supply is off
 

I charged mine from my pc and after taking the usb lead out, quite some time later, went to the battery display to connect to the internet and it was telling me the usb was still connected.....