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macintologist · Dec 25, 2005, 10:07 AM

I have a 12' Powerbook with only USB 1.1

I might be getting an iPod video soon, the 60gig one. If I have to let my iPod sit overnight to transfer all the music over, then so be it. My question however is about charging.

I know that USB doesn't have as much power as firewire. Right now I have my iPod 2G plugged into my firewire port almost all the time. Do iPods charge over USB slower than they charge over Firewire? What's the situation over in that department?

brapper · Dec 25, 2005, 10:12 AM

I'm not sure if they charge slower using USB, but you can still use your Firewire cable if you're only charging. It wont let you sync over firewire, but charging works.

macintologist · Dec 25, 2005, 10:15 AM

Life would be better if I just had a set of damn USB 2.0 ports :/

ghporter · Dec 25, 2005, 12:13 PM

The charging rate should be the same; USB power is +5VDC whether it's USB 1.1 or USB 2.0. However, since it takes longer to transfer data to the iPod, it will be running longer for that, and thus not be charging as fast during the transfer. For just charging, the iPod should charge just as fast on 1.1 as 2.0.

Mastrap · Dec 26, 2005, 08:16 AM

I use an old 12" PB at home and the iPod charges just fine.
Now the battery life on the other hand appears to be sucking.

ghporter · Dec 26, 2005, 08:35 AM

I think the algorithm the iPod uses for displaying battery charge condition is not terribly accurate. I like to leave my iPod charging overnight-it's smart enough to turn off the charging circuit when it's full, and that's completely in hardware.

I could draw you a diagram of a VERY simple charging circuit that automatically stops charging after the battery reaches its full charge...basically a diode is all that's needed, but adding a zener diode and a couple of resistors makes it more sensitive to the battery level.

In any case, by leaving it plugged into the AC adapter, I'm guaranteed a consistent charge rate and leaving it overnight guarantees a thorough charge.

macintologist · Dec 26, 2005, 06:21 PM

gh, it's funny you mention inaccurate charges. With my old 2G iPod, I notice that if I charge it through the AC adapter, overnight it will stop showing the charge animation on the iPod and say "fully charged" or whatever, but then when I plug it into my Powerbook firewire port, it will start charging again more and more as if it wasn't finished, or as if the AC can't fill it up completely.