Which is more powerful, 7.2 volts or 800 watts ?

Question

I'm trying to purchase a handheld vacuum with this power, but not sure which is a better one.

Answer 1

You need to specify more information.
Power is the ability to do work. In electrical terms, it is expressed in Watts. Electrical pressure is expressed in Volts. The electrical current is expressed in Amps.
Watts = Volts x Amps
In your example, if you are trying to use a 7.2 volt nicad battery pack to support a workload of 800 Watts, the battery pack must be able to supply a current of 111 Amps. (and it must be able to do this for as long as you want to run the vacuum cleaner.)
he higher the voltage of the battery pack, the less current it has to supply to produce the same amount of work.
Assuming that your battery pack can produce this work, the bigger battery pack will be able to do so for a longer time. Bigger also means heavier. So, another question will be how long do you need to go between re-charging?
You should be able to get all this information from the specifications of the vacuum, otherwise, you cannot answer this question.

It can get more complicated, if the chemistry for the batteries are different, some are more efficient than others, and therefore lighter for the same job. The more efficient charger will extend the effective life of the battery pack, but Will usually cost more.
You could also read up on deep-cycle batteries, and optimize you usage of them.

This may be more of an answer than you wanted. If so, get the names of some users (not the salesman), and see if they are willing to offer advice on which vacuum cleaner is more useful in your case, or find a repair house that fixes these 2 models and ask them.

Answer 2

800 watts is the amount of current used it may well be 800 watts of A/C current like a wall plug, where 7.2 volts is a dc battery that will or may very well have low wattage because of the drain high amperage has on a battery..they are different voltages and wattage but think of it this way the 800 watt vacuum will have more power but need a cord as where the 7.2 will have less but is more portable.

Answer 3

This probably won't help, but the relationship between power and voltage is:

Power = Volts X Current (or) P=Vi

It's really hard to compare the two vacuums when they state two different properties.

FYI, the power from a US outlet is normally at 120V, but if you have some kind of transformer (like the big blocks at the end of the cord you plug in the wall), that could change it. There, another point of confusion.

Answer 4

A variation of Ohm's Law:

P (power) = I (current) X V (voltage)

However, you sort of submitted an apples & oranges comparison and although one cannot make an accurate comparison between the two variables, I would go with the 800W device (assuming it plugs into a standard electrical outlet) since the 7.2V device would have to crank out a significant (and unlikely) amount of current to equal 800W.

Good luck!

Answer 5

Volts is one thing, watts another.
7.2 volts is more powerful than 6 volts
800 watts is more energy than 500 watts. (capacity of a battery for example, look at it like the sice of your fuel tank)

Answer 6

Tell me the amperage... Watts are a measure of power, and you need both the volts and amps of the 7.2V to get a good answer.

Answer 7

You cannot compare them because those two things mean completely different things.

To compare the power you need to know the number of watts for each.

Answer 8

7.2 volts

Answer 9

the 800watt but it is a plug in not cordless