Amps vs. Volts. Whats the equivalency?

Hi, I have a sweeper vac that is 7.2 volts. I need to relace it and am not sure if I should buy the same one or another one which says it is 2 to 4 amps. Which is better (as far as more power / suction). What is the equivalency of say... 4 amps vs. 7.2 volts? Thanks in advance.

thats kndaof a weird question since the two are completely different things.with amps being a function of volts on the resistant factor.
but assuming the resistance to be equal, then the 4 amps would be better...but i belive the 2-4 amps refers to the fact that the appliance is a variable resistor....while the 7.2 volts refers to the capacity of power (it can operate at that voltage or it need that specific voltage)///
go with the 4 amps...
The stupid part is, to figure out the power used by each, you would need both amps and volts for each. Which I doubt its going to list. Then just multiply amps x volts and you get your power.
Amps are a measure of current and Volts are a measure of pressure or difference of potential. Watts (power) are equivalent to Volts times Amps. I hope this helps.
Sounds like you are wanting to replace a battery operated DC device with a 120 volt AC device and you are trying to make a performance comparison.

Your vacuum probably lists the 7.2 volts because that's what it requires as a power input voltage from the little transformer that came with it.

Chances are, an AC vacuum drawing 4 amps will likely exceed the performance of your old DC sweeper. Just a guess though. If I'm correct, you are sort of trying to compare apples and oranges here.
If it runs on 7.2V, then it must be a rechargeable on batteries. The higher the amps..the more power, which is Watts = Volt x Amps.
Amps are coulombs per second, like miles per hour it is a rate of speed.

Volts are coulumbs per meter^2 or like psi a pressure.

So just like to get power from a water wheel where need pressure the weight of water in a bucket and velocity in the wheel turning to crush grain.

We also need both volts and amps to make power, hence

Volts x Amp = Power

High voltage therefore results in lower amps for the same amount of power. So if you are powering something from a battery you have less system losses due to I^2R in the higher voltage system and the battery will last longer.

This is why as battery technology has progressed the hand held gadget manufacturer's have been going to higher voltages.

Combined you want the highest of both volts and amps providing the highest overall product for greatest power.
I would agree with austin360

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