# Portable power source for low power usb device when away from computer?

Hope someone can help.  I've looked at all of the usb charger instructables, but most of them are for Ipods and such.  This device, I think needs to be low power like required by keyboard or mouse?  The manufacturer says this about powering the device:

"works only on voltages of 2000mA or higher, such as a PC. It will not work while connected to a USB or home charger, or with a Mac"

I would like to use this when away from my computer and think one of the Altoid power chargers would work.  Would like to make a solar one for the car, but regular for inside the house.

Thanks!!

pbates1237 years ago
This sounds real crazy. Maybe it is from a company coming out of China and someone who thinks they can speak English and isn't technical is trying to explain how to use it. I've seen some unbelievable wording lately!

Kelsymh alluded to it in his post and Lemonie said it also!

The Statement "Works only on voltages of 2000mA or higher" Does not make sense - 2000mA is amperage not voltage. The A in (mA) equals amps.

And if it will run on a computer USB port then 2000mA is not correct. By design USB ports can source a max of 500mA. I have seen the ports specified to source as high as 650mA.

So plugging this device to a USB port could destroy the port. If it works off of a USB port then it most likely does not draw more than 5Volts @ 500mA or 2.5 watts (5volts x .5amps). 2.5 watts can be expressed as 2500mW

Maybe they confused milliamps with milliwatts??? What is the device? You can also measure the current fairly easily.

Tell us more maybe we can help solve your dilemma..... regards, - Phil

seandogue7 years ago
2 amps is a pretty beefy load for carting around a battery pack to power such a device. Have you considered alternative peripherals that require a bit less power?

Alternatively, a string of X-Cell sized SLAs, (the X form factor stores about 5AHr @ 2.2V per cell) sourcing a 2A regulator would provide you with several hours of run time. Any similar grouping of SLAs would suffice. Gonna be heavy...
lemonie7 years ago

Uh, what is this 2A thing? Does it come with 4 USB leads?

L
kelseymh7 years ago
The manufacturer's statement, despite having stupid electrical errors, makes it clear that you cannot power it remotely the way you are describing.  The Altoid-based supplies mostly put out the 500 mA (current, not "voltage") that USB is designed for.

The manufacturer's statement says that your device requires 2000 mA (current, not "voltage").  Unless you can find something that puts out two amps at 5V, then you should follow that statement.