Fire alarm systems need to be inspected, tested and tagged annually. Testing must include all smoke detectors, manual pull devices, annunciators, visual indicators and strobes, control units, voice/alarm communications systems and any other devices that are a part of the fire alarm system.
it will need a port like this one to get more power from the usb since it only give 5.0 volts and this powered usb give up12 to 24 volts so you dont have that in a laptop and there is no way it could raise the power on the usb port in a laptop without damaging something .http://en.wikipedia.org/wiki/Powered_USB.
My laptop has an USB 3.0 port and it can charge the device with the laptop battery. However i used that port to power on the USB fan in order to cool down my laptop (it hardly worked out). Here's the point: When i powered off the computer and unplugged it. The fan was still working! For The WHOLE NIGHT.