Test cell phone charger current

[rjng]

I want to test this charger (http://dx.com/p/car-cigarette-powered-dual-usb-adapter-charger-white-2a-max-dc12v-58013) before connect to my cell phone.

I'd like to know if I just need to connect my multimeter electrodes in the negative and positive, or if I need to connect a resistor too (in serie with multimeter), and how much ohms the resistor needs to be (if necessary).

Thanks!

 

[eKretz]

You should be able to just connect the leads of the multimeter to + and - of the charger and check it that way. However, you only need to check it if you are worried about charging current being too low. The phone will only draw what it needs as far as amperage. If it is too low, the charging will just take longer.

 

[rjng]

I'm worried about maybe the current is very high and it could damage my phone. So, if the charger send 3 or 4A, my phone will get just what it wants?

I heard about a possible problem of charging Li-ion battery fast. Samsung told me that there is no problem no charge with 2A. Do you know about it?

 

[eKretz]

It could be 30 amps and it would work. The amperage rating on a source is only a maximum. Acceptable charge rate of a Li-ion battery depends on the battery capacity usually. If they told you it's OK I would listen to the manufacturer. The power adapter you linked doesn't control the charge rate of your phone's battery, the charging circuit inside the phone does.

 

[rjng]

Nice! I checked it here. The voltage is 4.71V, and the current is 2.38A.
When I plug the conectors to check the current, the chargers's led turn off, turning on when a disconnect it lol.
Thanks