Hi,

i bought a ca-100 usb charger for my Nokia N800.
Yesterday i streamed tv over wlan to mplayer and connected
the charger to my device. After a hour of watching tv the device
shutted down (empty battery). So the device needs more power than the
usb charger delivers ;(
Today i tested this usb charger without using my N800 and for
now it is charging for 4 hours ... and isn't ready yet!

Does someone else use this ca-100 charger with the same or similar
behavior? This thing is really useless if it needs several hours for charging
the N800. Could it be that my charger is defect?

UPDATE:
Ok, after posting this thread my device was fully charged!
So it needed about 4 hours of charging ... the standard charger (AC-4E)
needs only 2 hours for charging!

that is true if the amps going through is lower on the USB ports than the standard charger. For mine the standard charger reports DC 5V, 890 mA output.

BUT, don't go upping the amps...there is a limit. If you overdo it, it will destroy the battery and maybe your unit.



Luke

That was also my assumption. The old usb 1.x ports had 500mA... and i don't know whether the 2.0 ports have a higher limit.

I will try to exchange this usb charger against a normal one

I believe USB 2.0 has the same power spec as USB 1.0 - ie. max 500mA. Since this is approximately half of the current supplied by the AC adapter, it would seem correct that USB charging should take almost twice as long as the AC adapter.

Then again, battery charging may have nothing to do with amps and could be entirely dependent on voltage!

so i guess i can use a dc adapter/voltage booster (output = 6V, 380mA) to charge my n770 via pc usb at the same rate (ie. in 2 hours rather than 4 hours) as the ac adapter? i shouldn't destroy anything since: if current is additive, then 500+380 = 880mA, which is less than 890mA. is that correct?