How Much Power Does a Drill Battery Have? -12V | 18V | 20V

Drill battery is essential as a power source of the cordless drill. The amount of power capacity will save your time and money, So when you buy a drill battery, you should know about its power capacity and using time. So let’s see in detail how much power does a drill battery has?

Usually drill battery power depends on its voltage and its capacity. 12V and 1.5 Amh batteries have 18Wh minimum power and 20V, 5Amh batteries have maximum 100Wh power. But it can use in 500-1000 Watt tools because the tools do not require that much high power when it is operated.

It is not essential to know only about the power capacity of the battery. You should know how to use, save and maintain proper capacity with time. So I will explain to you all in detail about the power of the drill batteries. Keep reading on!

Related Topics

Fundemental of Drill Battery Power

How Power is Generated Using Drill Batteries?

Li-Ion battery inside mechanism

Typically drill batteries are made with Li-Ion. Li-Ion batteries are the most efficient and durable rechargeable batteries. There is a chemical process inside the battery, and it can store the electrons inside when it charge. When used, it can release the electrons when the circuit is short. This electric power is converted into mechanical power using a motor.

When the battery is discharged, it can charge for a minimum period. Normally it will take 30 mins to 5 hrs to charge a drill battery. Charge time can be increased with the battery technology. More than the Li-Ion, there are Ni-Cd batteries also. Those are not efficient like Li-Ion batteries.

How Drill Battery Power is Consumed?

A drill battery is an electrical component. Using the battery and motor, electric power is converted into mechanical power. Li-Ion is a battery, and it provides DC current. The power-up motor is DC and according to the commutator, there are two types. Brushless and brushed. Generally, brushed motors have carbon brushes, and those are less efficient than brushless.

Brushless motors are efficient and have less maintenance. When the motor is spin, it has connected to mechanical components. These components can produce an impact mechanism (helps to drive screws), hammer mechanism (helps to drill had material), or any torque increasing mechanism (sun planet gear system). When a drill is used its mechanical power is used to activate the system for drilling or driving.

How to Identify the Drill Battery Power?

Usually, drill battery power is identified with its notations. When you use a drill, you can see there are voltage and Amh signs. Those are the power notation of the drill battery. Normally a drill is designed for a fixed voltage and current. So you should select the suitable drill battery according to that.

Read More About – 09 Tips For Drill Battery – Extra Durability | Performance

How to Measure the Drill Battery Power?

Drill Battery Power Notations and Meanings

When you buy a drill battery, you can see there is a notation. Those are voltage and Amh.

Voltage (V) – Voltage is the potential difference of electrical power between two terminals. Normally there are 12V, 18V and 20V are the general use voltages of the battery. The drill has been designed according to the specific voltage limit.

Amh -(Ampere hours) – Battery capacity of the drill battery. This will explain how much amperes can use per hour continuously.

Imagine 2 Amh battery can provide 2-ampere current continuously in one hour and 1-ampere current will supply in two hours.

So let me explain all in detail.

What is Voltage and Ampere Hour?

Voltage is the electric potential difference between two terminals. These terminals are positive (+) and negative (-). Due to the potential difference(voltage), electronics are flown, and the current is on the opposite side. The voltage of the battery is a measurement of the lifetime, charging time, performance, speed of the tool. Due to the high potential difference, it can accelerate the electrons. Due to this, it will produce more power.

When considering the 12V,18V, and 20V batteries, 20V is the higher voltage, and it can be used longer than the other two batteries. Each and every tool is designed for the specified voltage. If the voltage is increased, its inside will be burned due to high electron movements. So never use an 18V drill battery in a 12V tool.

Ampere hours are the measurement of the battery capacity. It is like how much inside is big to store the electrons. Normally larger storage can provide the same current in the additional time period.

Imagine you have a 1.5 Amh battery.

  • If you use 1 Ampere, it can provide constant current in 1.5 hours
  • If you use 1.5 Ampere, it can provide constant 1.5 hours
  • If you use 3 Ampere current you can use that battery in half and hour (0.5 hrs)
Capacity (Amh)1A2A3A4A5A6A
1.51.5 hrs45 mins30 mins20 mins18mins15 mins
2.02.0 hrs1 hr40 mins30 mins25 mins20 mins
3.03.0 hrs1.5 hr1 hr45 mins36 mins30 mins
4.04.0 hrs2 hrs2 hrs1 hr48mins40 mins
5.05.0 hrs2.5 hr2.5 hrs1 hr 15 mins1 hr50 mins
6.06.0 hrs3 hrs3 hrs1 hr 30 mins1 hr 12 min1 hr
Drill battery current usage and time

I hope you can understand the facts.

Read More About – How Long Does It Take to Charge a Cordless Drill Battery?

Power Calculation of the Drill battery

The power of the drill battery is defined by the Watt-Hours. Watt-hour is the multiplication of Voltage and Amh. Every tool has a power consumption. This will explain how much watts need to operate the tool.

let’s explain this with a few examples

  • Dewlat DCF894B is powered by with 20V and 5Ah battery. The watt hour of this battery is;

Watt-Hours = Voltage * Amh = 20V * 5 Ah = 100 Watt-hour.

  • So if you light up 50-watt bulb using this battery you can use it for two hours.
Battery Voltage1.5 Ah2.0 Ah3.0 Ah4.0 Ah5.0 Ah
12V18 Wh24 Wh36 Wh48 Wh60 Wh
18V27 Wh36 Wh54 Wh72 Wh90 Wh
20V30 Wh40 Wh60 Wh80 Wh100 Wh
Power of the battery (w) with battery voltage (V) and current (A)

Read More About – Why is My Drill Battery Not Charging? Problems and Solutions

Why Maximum Power is Greater Than Drill Battery Power?

When you buy a cordless drill or driver, you can see there is a maximum power value. It will tell you if the tool is operated with its maximum power, it will consume that much power. Normally none is operated with the maximum. It will be mostly less than 60%.

Normally most drills are with 500 to 1000 watts required for maximum power. If the tool is operated with its maximum power, it will need a large number of watts. If the tool is operated like this, it will definitely be overheated. So don’t care about the high watts requirement of the tools. We are not able to provide a large number of watts for the maximum power using the battery.

How Much Power Does a Cordless Drill Use?

Drill Battery Power and Material Types

Drill battery power directly affects the material that we use. It means many brick drilling is carried on less than the same drill bit concrete drilling. This is pretty simple. When the material hardness is increased its toughness is also increased rapidly. Imagine if you use a 5 Amh battery to drill the brick and concrete with the same drill bit for the same depth. You can drill more holes in the bricks than the concrete.

When the toughness of the material is increased, its resistance also increases. So it will require more battery power for the hard material.

Drill Battery Power and Tool Mechanism


Drills are with few mechanisms in order to be efficient in the drilling process. In drills, there is a hammer mechanism and in the impact drivers, it is an impact mechanism. The Hammer mechanism is moving the drill bit forward and backward a thousand times per minute (BPM) and it will break the inner material into small parts. This is widely used for concrete, stones, and bricks. This is an additional mechanism rather than the spinning. So it will be efficient the work.

Let’s imagine like this. When we drill concrete with not activating the hammer mechanism, it will take more time than it is activated. So finally, it will increase efficiency and save the battery power.

This is the same for the impact drivers. Without an impact mechanism, it is difficult to drive the screws. It will take time. Using the impact mechanism will make it easy.

RPM and Drill Battery Power Consumption

RPM stands for revolution per minute. It will explain how many rounds a point will travel per minute around the center. This is widely used in machinery. There is a connection between power and RPM.

When we consider the power output of the rotating tools such as drills, drivers, two things are helped. Torque and RPM are them. when the tool is operated at High RPM, there will be less torque, and less RPM will have high torque. Because the power of the tool is the multiplication of torque and angular velocity (P = τ ω)

The power output of the tool is considered as constant torque, and RPm will act as a disproportion. When the battery capacity is increased by increasing Amh, it will directly affect the torque of the tool due to RPM.

Read More About – How to Increase the Power of Drill? – High-Efficiency Drilling

How to Save the Drill Battery Power?

You can save the drill battery power by using proper drill bits, drill bit angle, drilling mechanisms, and drilling machines. Additionally, you can save power using the drill in proper environmental conditions because high heat helps to discharge the drill batteries rapidly.

How a Drill Battery Power is Consumed

After charging a drill battery, its power is consumed in many ways. Mainly it is used for operating the tool. More than that, power is wasted due to environmental factors such as high temperature, heat, etc. So you should know how much power is needed for your job. According to that, you can use an additional battery also.

When a drill battery is open to heat, it will discharge quickly. Because inside reactions speed will occur fast and as result of this it will discharge.

If you do not use the proper angle drill bits, suitable mechanisms on time, you may waste the power of the drill batteries. So make sure to gain the maximum power from the drill batteries.

Ways to Save the Drill Battery Power

When you work with a drill, you should know how to save power? And gain the maximum efficiency from it. When you use a drill you should know how to operate it properly.

Follow the below steps for power save the drill battery

  • Use the proper angle drill bits with suitable mechanisms
  • Use hammer drill mechanism for brick, stones and concrete
  • Use impact mechanism for drivng screws
  • Use High RPM for soft material such as wood, aluminium
  • Use low RPM for hard materials such as metals, tiles etc.
  • Use proper dril bits for specific materials

How to Select the Proper Drill Battery?

What you Should Know Before Select a Drill Battery?

After you refer all in detail, let’s see how to select a proper drill bit for your task. Normally drills are available in the market with recommended voltages and Amh. So you had better use those. But more than that, you can select better batteries for long time usage.

When we consider the drill battery’s capacity affects the runtime of the tool, and voltage is a measurement of the speed of the tool and Amh is the power of the torque. So when you consider the same voltage with different capacity batteries, You should select the high capacity battery considering the same amount of voltage.

Do not use more voltage batteries in the tool. it will burn the tool finally.

What Capacity you Should Select?

When you select the capacity in the same voltage batteries, you should select the high-capacity battery because it has a high running time and longer lifetime.

Imagine you need to select 18V 2 Amh and 4 Amh batteries; you should select 4 Amh batteries. Using that, you can do more tasks than 2 Amh.


  • Cordless drill use less power (watts) than corded drills
  • Always use the high capacity battery in same voltage
  • Do not use more voltage battery in less voltage tools
  • Adjustable drill use few watts
  • Watt = Ampere X Voltage

Tom Mackency

Tom Mackency

Hi, I am Tom Mackency. It has been 10 years that I have been working as a professional woodworker since 2013. I am really enjoying my carrier by creating many kinds of projects in my workshop. But mostly I like for home improvement projects. Home improvement and DIY projects are the most interesting things for me. More than that, the coolest things are power tools. Those are very precious and efficient than a decade ago. So I try to introduce so many things about power tools, woodworking, DIY projects, home improvement and many more interesting topics here.