Electrical – Can you use different Voltage and Amps to a charge phone?

powersolar celltelephone

If I buy a solar panel that outputs 18 Volts and between 250-300 mili-Amps will it charge my phone? I looked at the charger output for my phone and it is 5 Volts and 1 Amp.
I know that Power (units in Watts) = Voltage X Amps.
So if
18 Volts X 250 mA = 4.5 Watts (for solar panel)and
5 Volts X 1 Amp = 5 Watts (for wall charger)
would my phone charge because you get roughly the same Wattage or does it have to what the charger output says?
If I use 18 Volts and 250 mA will my phone get fried?
Thank you, I am learning electricity

Best Answer

If you try to charge your 5V phone with 18V, you will FRY IT. NOT RECOMMENDED!

If you regulate the voltage down and try to charge your 5V phone with 5V @ 250~300 mA it will take 4~5x longer to charge vs. the specified 1A.

Yes, there are ways to change 18V into 5V with some boost in current. However such DC-DC converters lose some significant power because they are not 100% efficient.

An 18V @ 300mA solar panel is a POOR MATCH to a 5V @ 1A load. Probably a waste of money. Find a solar panel that is closer to what your load needs.