Volts vs Watts vs Amps?

[denniS_redbeast]

so I need a USB charging hub in my house so i found a few that look quite appealing (the links are below) however all have different watt, amp and volt outputs. I seem to not understand the differnce between the three. Can some one explain the defference between Volts, Watts and Amps???

 

http://www.newegg.com/Product/Product.aspx?Item=0S8-0045-00015&ignorebbr=1&cm_re=usb_charging_station-_-0S8-0045-00015-_-Product

 

http://www.newegg.com/Product/Product.aspx?Item=0S8-0088-00034&ignorebbr=1&cm_re=usb_charging_station-_-0S8-0088-00034-_-Product

 

http://www.newegg.com/Product/Product.aspx?Item=0S8-0045-00032&ignorebbr=1&cm_re=usb_charging_station-_-0S8-0045-00032-_-Product

[techguru]

wikipedia this question

its not that hard to understand

[MeltingPoint]

USB is 5V. Amps vary by source capacity.

 

Watts = Volts*Amps

[HmmR]

Electricity is measured in terms of amperage, voltage, and wattage. Amperage (amps for short) is a measure of the AMOUNT of electricity used. Voltage (volts) measures the pressure, or FORCE, of electricity. The amps multiplied by the volts gives you the wattage (watts), a measure of the WORK that electricity does per second.

Think of it this way: Electricity flowing through a wire is like water flowing through a garden hose. The amount of water that can fit through the hose depends on the diameter of the hose (amps). The pressure of the water depends on how far open the faucet is (volts). The amount of work that can be done (watts) depends on both the amount and the pressure of the water (volts x amps = watts).

[TheKDub]

[phillrulz]

Volts can be seen as pressure, amps can be seen as flow rate and watts is the resultant force. here is my tesla coil http://puu.sh/gKPg7.jpg, it has very high voltage but very small current so the power ( watts) is medium.

 

With the multi port charger you want to look at how much current can it output from each slot, usually they will be uniform across all slots however different brands may have different current capabilities, like my charging dock can output 60w from 6 usb ports, thats 12A at 5v, 12/6= 2 so it can output 2A on all the slots at once, however it can do upto 2.4A on one slot. With high battery capacity you need high current to charge it efficiently. So an ipad will struggle if charge with a 2A source vs using a 2.4A source.