iPod Chargers Question

[Talal Itani]

Why is it that some USB chargers cannot charge the Apple iPods? I tested
multiple USB charges, and only those that say "for iPods" work.

 

[PhattyMo]

Why is it that some USB chargers cannot charge the Apple iPods? I tested
multiple USB charges, and only those that say "for iPods" work.

There's some tricks..
Some older iPods will work on any USB (+5V) source..others require that
the D+ and D- pins in the USB plug are tied high,or low through a ~10K
resistor (i don't remember the exact details)..and yet newer models,like
the 2nd-gen Nano I have here won't charge with any type of "dumb" USB
port. It needs an actual USB host to negotiate power requirements
with... no host,no negotiation,no charge.

 

[Dave]

There's some tricks..
Some older iPods will work on any USB (+5V) source..others require that
the D+ and D- pins in the USB plug are tied high,or low through a ~10K
resistor (i don't remember the exact details)..and yet newer models,like
the 2nd-gen Nano I have here won't charge with any type of "dumb" USB
port. It needs an actual USB host to negotiate power requirements with...
no host,no negotiation,no charge.

Interesting. I wondered the same thing about my Blackberry phone... I can
plug it in to a computer's USB port, but unless there is BB device manager
software installed on that machine, I get "insufficient charging voltage
available" although I can still access the device as a removable device,
i.e. I can do everything but charge it.