# Is it okay to use an AC adapter with same voltage, but higher amperage than required?



## MM9

Hi, I have a device that requires 9v/850 mA of power. I have an AC adapter that is rated at 9v/1300 mA. Will the device only draw the power it requires, or do I risk damage? What about with an underpowered 9v/700mA adapter? Thanks.


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## kendallt

overpowered is better than underpowered

It will only draw what it needs, if there isn't enough power(wattage) devices will often draw more voltage to make up the difference and tend to overheat.

Make sure that the supply is at least the minimum requirement, and that the polarity of the plug is correct

That said, most power requirements are 'nominal' meaning that it's what they expect, actual value often varies a great deal, 10% +/- is often considered acceptable for most electronics. 

Ken.


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## Done_Fishin

Whenever supplying a power feed to any electrical / electronic device You must keep to the Voltage specifications that are given. 

If you give a higher Voltage than is specified it means that your device will draw too much current, overheat and probably burn out. 

If you give a lower Voltage than is specified, the device will be underpowered and may work sporadically, if at all.

If the power source hasn't the ability to supply the current required, the power supply output Voltage will drop, the power supply may well overheat and burn out.

If the power source has more than the required current, it should work quite nicely, It won't stress either the power source or the device being powered.


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## DonaldG

The quick answer to your question is:

Yes, it is safe to use a greater amperage. The device will only draw what it needs.


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