Electric usage : 8 Amp Corded Drill vs 24 Volt Cordless dril

[Clarence Martinn]

Trying figure out how much electricity these 2 drills use.

1. 8 Amp corded drill used for 2 hours

2. 24 Volt Cordless drill with a 2.0 Amp Hour lithium Battery.

What uses more electricity? The corded drill for 2 hours, or Charging the 2.0 Amp Hour battery?

[Joe Jensen]

Depends completely on how loaded the drill is. If running a light load both drills will consumer less power. In general with battery power, there is wasted energy in the heat loss in the charger, and the heating of the battery when in use. But with the data you shared the question is not possible to answer.

[Joe Jensen]

Watts is a measure of power. Energy consumed is measured in watts per hour. In your corded example the drill fully loaded (almost stalled) would consume 8 amps. Voltage is 120 volts. Watts would be 120V times 8A = 960 watts. We don't know how much current the cordless drill consumes. We do know the battery is 24 volts and 2A hours. That means it can supply 24 volts at 2 amps for one hour.

[johnny means]

The corded drill would use more electricity because the cordless would die well short of running for 2 hours.

[Frank Pratt]

I've never seen studies comparing the efficiency of corded vs cordless drills, but I tend to think that the cordless would do more work for a given quantity of energy. There is little incentive for a manufacturer to make an efficient corded motor, whereas in the cordless arena, getting the most out of what a battery will give is paramount. There are losses with charge/discharge, but I don't think those are huge.

[Bill Dufour]

Watts is a measure of power. Energy consumed is measured in watts per hour. In your corded example the drill fully loaded (almost stalled) would consume 8 amps. Voltage is 120 volts. Watts would be 120V times 8A = 960 watts. We don't know how much current the cordless drill consumes. We do know the battery is 24 volts and 2A hours. That means it can supply 24 volts at 2 amps for one hour.


960 watts times
two hours =1900 watt hours

say one amp times 24 volts for two hours= 48 watt hours

[Rich Engelhardt]

Way too many variables to even begin.
This is not a simple question.

The way the question is asked, the specs on the charger are needed & those vary wildly depending on brand.

[Wayne Cannon]

It would be very difficult to estimate due to very significant energy conversion losses -- easier to actually measure the current draw.

You can't just figure wattage, as there are major energy losses in conversion from electrical-to-chemical during charging, and chemical-to-electrical-to-mechanical during use -- easily losing as much as 60% (based on major power-generation plants' 40% conversion efficiency -- slowly approaching 60% efficiency in the most efficient new power plants -- where they REALLY optimize efficiency). This is one of the great fallacies of electric cars -- they're actually more wasteful of energy than direct fuel-to-mechanical due to energy conversion losses when you figure the ENTIRE process.

[George Yetka]

I believe if the drills produced equal power across the board the cordless would take more input power due to energy loss on charging and because it is operating at a lower voltage

That being said the drill probably doesnt produce the same power as the corded and will only last a short while running.

[Rich Engelhardt]

Again guys the question is this:
"
What uses more electricity? The corded drill for 2 hours, or Charging the 2.0 Amp Hour battery?"

The OP is asking if the battery charger uses more electricity to recharge the battery than the corded drill uses.

[George Yetka]

2 hours of corded use vs 15 minutes of charging. (not even looking at the corded drill or what power is lost in the battery)

I would have to say the corded uses more power. The couple of chargers I looked at for the 24 volt were rated at similar amperage to the corded drill. Even if it took 30 minutes to charge over 2 hours the drill would use more

[John Lanciani]

So to make it as simple (and unrealistic) as possible, if we ignore all of the losses and efficiencies and all of the other real world factors that make this a difficult question to answer; The 24 volt 2 amp hour battery contains 48 watt hours ofenergy and using the 8 amp 120 volt drill consumes 960 watt hours of energy per hour.Using the corded drill at full output power for two hours consumes 40x more energy than the battery contains.

[David Buchhauser]

So to make it as simple (and unrealistic) as possible, if we ignore all of the losses and efficiencies and all of the other real world factors that make this a difficult question to answer; The 24 volt 2 amp hour battery contains 48 watt hours ofenergy and using the 8 amp 120 volt drill consumes 960 watt hours of energy per hour.Using the corded drill at full output power for two hours consumes 40x more energy than the battery contains.


But then the question is - how long will the cordless drill run under full load before the battery dies? Much more information would be needed here to get anywhere close the an actual factual answer.
David

[Dan Friedrichs]

Start at the "other" end - if both drills do the same work for the same period of time, they are outputting the same mechanical power.

Both have some inefficiency in converting their input 120V into mechanical power. The corded likely has brushes (lossy) and may not be designed for efficiency (no real need). The cordless might be brushless (more efficient) but there are losses in charging and discharging a battery.

For a particular set of example drills, you could measure and compare. But there's no general answer.

[Malcolm McLeod]

But then the question is - how long will the cordless drill run under full load before the battery dies? ...

But then the next question is, "Who believes that a corded drill will run for 2 hrs at full load and not melt?"
Followed by, "Who makes it?"
Followed by, "How does it compare to Festool?"
Followed by, "When do they go on sale?"
Followed by, "Does that include shipping?"
;)

[Jim Dwight]

I think the answer is pretty easy but only because the two drills are not even close to comparable. The corded drill will consume a lot more power, even if lightly loaded, because it is a much more powerful drill. Loading it lightly will not make it come as little power as a cordless drill. To prove it you would need to measure consumption but I am pretty darn sure this is the case.

For comparable sized drills, the cordless will consume more because of the ineffiency of converting the AC to DC. Differences in designs of motors is an even smaller factor.

But big drills consume more electricity than little drills.

[Bill Dufour]

To confuse the issue even more I found out that Stanely makes a pneumatic angle grinder designed for underwater use. How about that compressor efficiency and hydrodynamic drag on the spinning disk. I assume most would use a hose not an air tank. Their underwater drills seem to all be hydraulic as used by the power companies along with hydraulic chainsaws for working up power poles
Bill D.

https://www.stanleyinfrastructure.com/products/underwater-grinder

https://underwaterhydraulics.com/collections/stanley-underwater-drills

[johnny means]

Again guys the question is this:
"
What uses more electricity? The corded drill for 2 hours, or Charging the 2.0 Amp Hour battery?"

The OP is asking if the battery charger uses more electricity to recharge the battery than the corded drill uses.

Actually, the OP starts by declaring that the question is, "Trying figure out how much electricity these 2 drills use." The post is ambiguous, at best. I think it's safe to assume that the first line and the title clearly state the OP's intention.

[Rich Engelhardt]

I think it's safe to assume that the first line and the title clearly state the OP's intention.Then how does that explain the OP's last 2 sentences?
"What uses more electricity? The corded drill for 2 hours, or Charging the 2.0 Amp Hour battery?"

Ok - edit to say:

We could each go back and forth about what the OP was after - but - why?

The OP can come back and clear it up when he wants to.

[Eric Arnsdorff]

It’s very clear that what’s being asked is which would ultimately make the stronger joint. Clearly the answer is the green one!
Sorry - I couldn’t resist!

[Doug Garson]

This is one of the great fallacies of electric cars -- they're actually more wasteful of energy than direct fuel-to-mechanical due to energy conversion losses when you figure the ENTIRE process.

Mind showing us the source for this?

“EVs convert over 77 per cent of the electrical energy from the grid to power at the wheels. Conventional gasoline vehicles only convert about 12 per cent – 30 per cent of the energy stored in gasoline to power at the wheels,” according to the US Department of Energy. The difficulty for ICE vehicles is by providing driving flexibility; they sacrifice thermodynamic efficiency. As The Driven (https://thedriven.io/2019/12/15/is-a-diesel-cleaner-than-an-electric-car-in-australia/) points out, “petrol and diesel cars are very inefficient in converting the energy in their tanks into motion at the wheel ... over 60 per cent of the energy is wasted as heat.”

https://www.energycouncil.com.au/analysis/evs-are-they-really-more-efficient/

Just like energy efficiency has driven down emissions in the power sector, efficiency is also a primary driver of cleaning up the transportation sector. Electric motors makes vehicles substantially more efficient than internal combustion engines (ICEs). Electric motors convert over 85 percent of electrical energy into mechanical energy, or motion, compared to less than 40 percent (http://large.stanford.edu/courses/2011/ph240/goldenstein2/) for a gas combustion engine. These efficiencies are even lower after considering losses as heat in the drivetrain, which is the collection of components that translate the power created in an electric motor or combustion engine to the wheels. According to the Department of Energy (DOE) (https://www.fueleconomy.gov/feg/evtech.shtml), in an EV, about 59-62 percent of the electrical energy from the grid goes to turning the wheels, whereas gas combustion vehicles only convert about 17-21 percent of energy from burning fuel into moving the car. This means that an electric vehicle is roughly three times as efficient as an ICE vehicle. Needing less energy to power your car also helps bring down the cost.
https://www.nrdc.org/experts/madhur-boloor/electric-vehicles-101

[Rod Sheridan]

Trying figure out how much electricity these 2 drills use.

1. 8 Amp corded drill used for 2 hours

2. 24 Volt Cordless drill with a 2.0 Amp Hour lithium Battery.

What uses more electricity? The corded drill for 2 hours, or Charging the 2.0 Amp Hour battery?

The cordless drill could draw approximately 24 watts of power for 2 hours from the battery. That wouldn’t be enough energy to drill itself out of a wet paper bag.

The AC powered drill, if it’s a good one, could output 2 or 300 watts worth of power for 2 hours.

The only time I’ve ever run a drill for 2 hours was using my Holehawg to winch 80 batteries that weighed 700 pounds each up a 50 foot ramp.

Where I live the AC drill would cost 20 cents to winch all batteries, the cordless couldn’t winch any, although it would only cost 1 cent to recharge…..Rod

[David Buchhauser]

Trying figure out how much electricity these 2 drills use.

1. 8 Amp corded drill used for 2 hours

2. 24 Volt Cordless drill with a 2.0 Amp Hour lithium Battery.

What uses more electricity? The corded drill for 2 hours, or Charging the 2.0 Amp Hour battery?

Just curious about your question. Are you debating whether to buy a corded drill or a cordless drill? If you need to operate the drill continuously for several hours, then by all means buy a good quality corded drill. Maybe something like one of the higher end Milwaukee or equivalents. For more occasional light/medium duty non-continuous use, then perhaps the cordless drill would be a better choice for you. I own and use both, depending on the particular circumstance.

David

[Doug Garson]

I think the question is poorly structured, it's apples and bananas. A much better question would be "Which drill will consume more electricity to drive 100 three inch drywall screws into a block of oak?"
I agree there probably isn't a commercially available drill out there that can run continuously under full load for two hours straight.

[Jerry Wright]

Based on these answers, we should all keep our day jobs. If a corded drill had no cord, I would choose that one!!!

[Alan Rutherford]

You can measure the amount of electricity used easily and inexpensively with a watt-hour meter (https://www.amazon.com/kwh-meter/s?k=kwh+meter) but it doesn't mean anything unless the drills are doing comparable work. How about this:

Start with a charged battery and do something with the cordless untill the battery dies. Then recharge it while using a meter on the charger to see how much power was used. Then meter the corded drill while doing the same work the cordless did and you have your answer.

[Clarence Martinn]

Try to simplify this .:)

Using that same cordless drill with 2 1/2 inch Wood Screws drilling through 8/4 Red Oak; how long would the battery last , before it dies out, and needs to be recharged ? If it is a 2 Amp Hour Battery, would it last 2 hours ?

[johnny means]

It’s very clear that what’s being asked is which would ultimately make the stronger joint. Clearly the answer is the green one!
Sorry - I couldn’t resist!

That could vary based on whether it was end grain or long grain.

[Doug Garson]

That could vary based on whether it was end grain or long grain.
And what brand of duck tape is used. :p

[David Buchhauser]

Try to simplify this .:)

Using that same cordless drill with 2 1/2 inch Wood Screws drilling through 8/4 Red Oak; how long would the battery last , before it dies out, and needs to be recharged ? If it is a 2 Amp Hour Battery, would it last 2 hours ?

The answer depends on the time and current draw per hole. And how many screws are you "drilling". I would assume you are drilling a pilot hole first, and then driving the screws into the hole. The battery in question can supply 2 amps for 1 hour, 1 amp for 2 hours, 1/2 amp for 4 hours, and so on. You can buy batteries with a greater Amp Hour rating, and additional batteries as well. In my case, I use a Milwaukee M18 drill with 5 ah batteries. I have spare batteries, so there is always a fully charged spare when the one in the drill (or driver) runs low. I find the cordless drill with high torque DC motor to be much more pleasant to use for driving screws than using a corded drill with AC motor.

David

[Doug Garson]

Try to simplify this .:)

Using that same cordless drill with 2 1/2 inch Wood Screws drilling through 8/4 Red Oak; how long would the battery last , before it dies out, and needs to be recharged ? If it is a 2 Amp Hour Battery, would it last 2 hours ?


Amp hour (Ah) is a unit of measurement that has nothing to do with power and it’s a totally different unit than Amp (Ampere). Amps are used to describe amp hour, but they are different units of measurement.
Amp hour describes the capable charge of a battery. Theoretically, we can draw 2 amps, continuously, for 60 minutes before our 2 amp hour battery is drained. Just think of amp hour as a way to know that one battery holds more of a charge than another. Just like the size of the gas tank in a car.
That said, if the drilling operation drew one amp continuously then yes a 2 amp hour battery would last two hours.

[Frank Pratt]

I guess it depends on which drill is being used to install dominos or biscuits, or the other way around.

[Dave Sabo]

Try to simplify this .:)

Using that same cordless drill with 2 1/2 inch Wood Screws drilling through 8/4 Red Oak

Hope you're not planning on just going at it with the screws without pre-drilling a pilot hole ? Because at that point, it ain't gonna matter which scenario uses less electricity. The results are going to be poor using either tool.

[Andrei Telitsyn]

The cordless drill could draw approximately 24 watts of power for 2 hours from the battery. That wouldn’t be enough energy to drill itself out of a wet paper bag.


Not exactly. Cells in those battery packs are designed for high current discharge and the dependency is far from linear.
So, I would say, 2Ah would yield about 3 minutes at max torque. With total power, assuming standard values of 20V and 30A, can be somewhere close to 0.75HP.

[Frank Pratt]

Not exactly. Cells in those battery packs are designed for high current discharge and the dependency is far from linear.
So, I would say, 2Ah would yield about 3 minutes at max torque. With total power, assuming standard values of 20V and 30A, can be somewhere close to 0.75HP.

You're assuming close to 100% efficiency, which is not even close to the actual efficiency.

[Andrei Telitsyn]

You're assuming close to 100% efficiency, which is not even close to the actual efficiency.

That would be the upper limit, in terns of 'energy spent'. Portion of consumed energy would pay for inefficiencies, yes.