8V power supply on a 5V device

[Stiganator]

I brought my eReader home and only brought the USB cord. Appartently, if the battery is fully discharged it won't work via USB. I don't have the AC charger, but I do have a AC charger from a portable DVD player, but it is and 8V output vs the eReader being a 5V device.

If I plug it in will it kill the device?

 

[bcracer220]

its not a good idea, it also depends alot on amps,do u have those ratings? but dont do it its not worth the risk

 

[Rubycon]

That's a 60% overvoltage. I would not risk it.

 

[Stiganator]

I found an old diskman charger that fit, got enough juice to run it off USB.

Overvoltage is bad.
Undervoltage is bad.
Overcurrent is bad.
Undercurrent is ok, it will just take longer to charge.

Is that about right?

 

[Soundmanred]

"overcurrent" is fine. It will draw what it needs. The voltage is your main concern.

 

[Modelworks]

You also have to be careful with some adapters that say one voltage, but output a different one when not under load.
You can often take an adapter that says 5volts and measure the output to find its 50% higher when not under the load it was designed for.