iPod question

[CruisinCruzan]

I saw this on another site and since I am ignorant about these things thought I would get opinions of those more knowledgeable. I was searching for power options for an iPod Nano (new version)and the poster stated that since it is a USB capable device that it can handle up to 30 volts so connecting it to a 12 volt source without voltage step down is OK. Is this true?

[rickmoen]

I'm planning on mounting an iPod Nano on my bike, as well. However, I don't think that I'm going to power it at all - just rely on battery. The iPod Nano is advertised to have at least 12 hours of battery life. My cheeks won't go close to 12 hours, so (in theory), it shouldn't need any power. Ride during the day; charge it at night! Using battery power means not having to worry about ground loops for the Autocom or running power wires and trying to hide them. I'll probably use RAM mounts to hold it on the handlebar. Rick

[velomoto]

I saw this on another site and since I am ignorant about these things thought I would get opinions of those more knowledgeable. I was searching for power options for an iPod Nano (new version)and the poster stated that since it is a USB capable device that it can handle up to 30 volts so connecting it to a 12 volt source without voltage step down is OK. Is this true?

 

A much safer method would be to run the 12v supply into an ipod car charger. In order to connect your iPod to the 12v supply you'd need to hack an iPod-USB cable or build some sort of special connector. Where did you see thread on powering an iPod with 12v?

[smiller]

USB DC supply voltage is 5 volts, same as that used for the DC power input on most portable players so there's no real advantage in using the USB power input on the player as you still need to step down to 5 volts either way.

 

As Rick mentioned the best solution in most cases (unless you really need more than 12-14 hours run time per day) is to just run on internal batteries and recharge at night. Besides being the simplest solution this will also eliminate the potential for ground loop problems that are so common to motorcycle audio installations.

[CruisinCruzan]

http://www.advrider.com/forums/showthread.php?t=113241&highlight=powering+ipod is the link to the discussion on Adventure Rider. It looks like it is because of firewire not USB. At any rate, knowing my riding habits I doubt I will be in the saddle long enough in a day that I would deplete the battery charge so I will just use it on battery, recharge at night and also avoid the bike powered noise issues. Thanks for the feedback

[velomoto]

One other detail I meant to include - if I'm remembering this correctly the USB power supply signals are rated for a minimum of 4.25V and a maximum of 5.25 or 5.5v. I don't recall a 30v spec. with USB - possibly a maximum before damaging the device?

 

In any case there are many inexpensive 12v iPod chargers (under $10 + shipping)...

 

The battery pack in an iPod Nano is 3.7V. The external 12v supply needs to be stepped down to something near 3.7v or else the battery will fry - this is probably a two step process: the external converter which drops the voltage to the USB level and another regulater in the iPod or iPod-plug. My point is that applying 12v directly to the Nano may damage it. Also keep in mind that there is a lot of "noise" on the bike's power supply - 12v may be the nominal value but with all the high power switching going on (lights, etc) there will be voltage spikes which will be considerably higher.