Couchrocket Posted February 27, 2008 Share Posted February 27, 2008 OK, hoping one of you really computer / electronics experts out there can help me w/ a question. I have an iPhone, and a Jawbone bluetooth device. The Jawbone came with a charger that is a USB cable that can either be plugged into the computer USB port, or a "provided" AC adapter. The iPhone also has a USB cable that works the same way. I purchased a "car charger" for the iPhone that is also a USB cable type device, that plugs into a cigarette lighter "adapter" w/ USB port on it. The question is: is the voltage, amps, or whatever (I'm non-electrical) for all USB-charged devices the same? In other words, could I use the iPhone car charger to also charge the Jawbone? Just carry the one "cigarette plug w/ USB port" on it in the car and plug either the iPhone cable, or the Jawbone cable into it? Or is there a danger that I'll blow up the Jawbone? Any insight into these mysteries would be appreciated. Oh, and beyond just iPhone / Jawbone.... the larger question of "USB charging" in the car is of interest to me for other devices. What say you all? Thanks! Link to comment
Gregori Posted February 27, 2008 Share Posted February 27, 2008 The adapter wth the USB port will provide 5v, and charge (or power) any USB gizmo that doesn't need more power than it provides. I recently came across a cool cigarette adapter that has two USB ports to power multiple devices. Link to comment
russell_bynum Posted February 27, 2008 Share Posted February 27, 2008 OK, hoping one of you really computer / electronics experts out there can help me w/ a question. I have an iPhone, and a Jawbone bluetooth device. The Jawbone came with a charger that is a USB cable that can either be plugged into the computer USB port, or a "provided" AC adapter. The iPhone also has a USB cable that works the same way. I purchased a "car charger" for the iPhone that is also a USB cable type device, that plugs into a cigarette lighter "adapter" w/ USB port on it. The question is: is the voltage, amps, or whatever (I'm non-electrical) for all USB-charged devices the same? In other words, could I use the iPhone car charger to also charge the Jawbone? Just carry the one "cigarette plug w/ USB port" on it in the car and plug either the iPhone cable, or the Jawbone cable into it? Or is there a danger that I'll blow up the Jawbone? Any insight into these mysteries would be appreciated. Oh, and beyond just iPhone / Jawbone.... the larger question of "USB charging" in the car is of interest to me for other devices. What say you all? Thanks! Yep. That should work fine. I do that all the time. The car charger for my blackberry is frequently used to power my GPS, and the AC adapter that we plug the iPods into also works to charge my blackberry, or power the GPS. Link to comment
steveknapp Posted February 27, 2008 Share Posted February 27, 2008 I've had a few issues with devices that won't take a charge, but there is no chance of harm in trying. USB is actually pretty smart in this respect. Link to comment
stubble! Posted February 27, 2008 Share Posted February 27, 2008 I have purchased a couple of these for use in my tank bag and in the car and have had good results. Some devices are indeed finicky from what I gather, but I haven't had any trouble with my various devices and this USB charger. One of my rainy day project ideas is to make my own USB power distributution device, or at the least to wire the above into an SAE connector and ditch the cig lighter form factor. Link to comment
smiller Posted February 27, 2008 Share Posted February 27, 2008 The voltage and connectors on all USB power supply devices are the same, although the current capacity can vary. The latter factor shouldn't cause a problem though, the worst effect would probably be that the device's internal battery might charge more slowly if the supply isn't capable of supplying all the current it can use. Some devices actually require a 'real' USB connection (i.e. to a computer) to charge properly. For this reason some USB power supplies also provide pulses on the data pins (in addition to powering the power supply pins) to spoof devices into thinking that they are attached to a computer. Luckily this requirement isn't very common. Link to comment
steveknapp Posted February 27, 2008 Share Posted February 27, 2008 My phone needs to enumerate with the PC before it will charge. There is part of the spec in which a device can not consume more than X current until the PC has queried it. At that point the PC can query the current needs and enable the device to a current limit that the USB port can provide. Powered hubs can often provide 1/2A (max spec) per port, where a passive hub provides only a fraction of that, limited by the 1/2A max draw it has from it's host. Link to comment
Woodie Posted February 27, 2008 Share Posted February 27, 2008 I used an off-the-shelf USB 4 port hub to power both a cell phone and my Treo for all-day riding to/from the UN last fall. Nice! Link to comment
Couchrocket Posted February 27, 2008 Author Share Posted February 27, 2008 Thanks all! This place is great!!!! S. Link to comment
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