OT: Question on charging devices - How much is too much?

[Gilbert]

I have a new 3G travel router that has a rechargable battery. It came with an AC adapter. I would like to buy a car charger for it but the manufacturer doesn't sell one. I have found an 12 V car adapter that fits but states that it outputs 5V 2.5A. The device states it uses 5V 2A.

In asking at the local Fry's electronics, I was told that the charger would work as the device will just take what it needs. Since I know very little about electricity, I am hoping someone here may be able to guide me to a correct answer.

Am I going to do any damage if I use this car adapter that outputs more than what the devices states is needed?

[Jimmypoo]

Those are capable outputs of up to 2.5a. The device will draw what it was designed to draw.

[DRR]

Yeah you're good.

Voltage should match as closely as possible though - so if you device states 5V 2A, 3V 2A would not be enough to power it, and more than 5.5V or so (on the power supply,) would likely damage the unit.

[SDGuy]

Just be sure to get the polarity right!!!!

[space-time]

Gilbert wrote:
I have a new 3G travel router that has a rechargable battery. It came with an AC adapter. I would like to buy a car charger for it but the manufacturer doesn't sell one. I have found an 12 V car adapter that fits but states that it outputs 5V 2.5A. The device states it uses 5V 2A.

In asking at the local Fry's electronics, I was told that the charger would work as the device will just take what it needs. ...

yes, the output 5V 2.5A means the voltage is constant (5V) and the MAXIMUM current is 2.5A. If you connect a small load, it may take only 1 A for example.

So what Fry's employee told you is correct, a rare case these days. many employee (but not all) are paid minimum wage and know nothing about what they sell.

[Gilbert]

Thanks for the input! Will double check the polarity before using the charger with the device.

And good to know the employee at Fry's was spot on. Will be sure to find her the next time I have a question.