Does this require a battery or an external power source?
1278827
gets power thru the phone line (it has to be connected to your land phone line)
619047
The power source is a little circular 3V internal battery. It is included with the device. There is also a light receiver on the face of the device that I assume contributes to managing battery power.
1765961
I guess there is a external power input, but it does not come with an adapter. so pretty much batteries only.
586146
No, it needs a power source. Ac/ DC connection. No headphone connection either
1426962
Yes it requires a battery. It uses very little energy even with frequent usage. I've had mine for a year and haven't needed to change the battery yet.
1416837
Although the user manual does not say that it needs a power source, it came with a USB cable. I was not sure why, later I noticed that the device has a mini USB port on the side. I had it connect to my Cable box that has a USB port. The device did not work properly (it kept flickering) without using USB cable. It works perfectly now.
68007
It does not require batteries, but does have to be attached to a USB port. This company offers a different version which is what you are looking for.
382419
None, comes with mounts so all you need is a power source and a togle switch.
1391875
you don't need a power source, the display goes when you cycle. comes with a battery.
27984
It does not have a battery if that's what your asking. It needs to be constantly powered through USB and needs to be connected to a device that can use its drivers, otherwise it wont work.
1704629
Require a power supply: No; Batteries: My book says "to provide back up power". Others have mentioned that the batteries don't last to long
1999078
No, an external battery isn't needed. Anything that gives off power and has a usb connection will work. A computer, gaming console, the wall adapter for your iPhone charger.
1928999
No battery needed. You recharge it with a USB cord connected to your computer.
796051
Yes. It has a battery and I have used it both ways which is the reason I bought it. If I need to use it without electricity I can just as well.
1076112
It comes with it's own power supply and plug. This item does not use batteries.
1551261
The does not have a battery. It works with an adaptor that plugs into your regular wall outlet.
2248803
It requires a power source. You can use a BEC, or a (4) cell NiMH or NiCad battery (4.8v-6v)