As computers are being used more and more in education, there will be soon no role for teachers in the classroom. Do you agree or disagree?

The Core of A 20V Cordless

Drills

The heart of a cordless

tool

is its

motor

and its

battery

. The best 20V cordless

drills

have a

brushless

motor

and a 12, 18, 24- or 36-

voltbattery

Correct your spelling

volt battery

at their core. You may have noticed that all these

batteries

have various

Ampere-Hour

values.

For example

, you will find a 20V

battery

with a

capacity

of 1.5, 3, 4, 5, 6, 9 and 12Ah. What Is the Relationship Between

Voltage

and

Ampere-Hours

? A

battery

's electrical potential is called

voltage

. It is the measure of the

power

or

energy

in the

battery

. An ampere is the measure of the rate of current or electron flow through the conductor. The conductor is the wire laid into the

circuit

.

Ampere-hour

is the total amount of charge in a

battery

that allows one ampere of current to flow through the

circuit

in one hour. In corded

tools

, it is measured in

amperes

, i.e., the amount of

power

drawn by the

tool

is virtually infinite.

In other words

,

voltage

is the

power

and

ampere-hours

are equivalent to the

runtime

. These two terms come from the

battery

’s actual

capacity

- the watts-hours.

Ampere-Hours

x

Voltage

= Watt Hours If you look at the label of the

batteries

. The

capacity

is mentioned in watt-hours. The larger the fuel tank - watt-hours the higher the

energy

potential. If you dissect your

battery

you will see it is made of individual

cells

connected in

series

. Each of these

batteries

delivers a certain

voltage

.

An

Change the article

A

show examples

18650

battery

is a Li-ion cell

that is

18mm by 65mm in dimensions. It is slightly larger than the AA

battery

. Higher

capacity

and discharge rate They are used in laptops, cordless

tools

, and high drain devices.

This

is because they have a higher

capacity

and discharge rate. Typically,

an

Change the article

a

show examples

18650

battery

is slightly more than 3.6 volts. In a fully charged state, they produce slightly more than 4V. There may be anomalies depending upon the

tool

, temperature of the

ambiance

Change the spelling

ambience

show examples

, etc. But usually, it means if you need a 12 Volt

battery

then

string three of them in

series

. If you need an18-volt

battery

then

connect 5

cells

.

This

means that if you want more

power

simply add another cell in

series

. In theory, you will

increase

the

power

by 4V. The

tool

industry has set the standards to 12, 18, 20 and 36V. These standards form the basis of the

tool

platforms and outdoor equipment. Increasing in

Voltage

and

Ampere-Hours

Now let us discuss how to

increase

the

ampere-hours

on the

tool

. If you ignore certain factors 3.0

ampere-hour

will

getyou

Correct your spelling

get you

3

amperes

of current in an hour. Unlike

voltage

,

this

is a variable number. You can draw a higher amperage from the

battery

and get lesser

runtime

.

This

is a linear relationship. You get 2.5

amperes

on a 5.0 amp-hour

battery

and 2 hours of

runtime

. You can draw 6

amperes

from a 3-

ampere-hour

battery

and get only 30 minutes of

runtime

. Most Li-ion

batteries

run around 2.0 Ah. You can

increase

the

voltage

by connecting the

cells

in

series

.

This

means if you connect three 3.6V

battery

in

series

you get 12V but only 2.0 Ah. To get a higher

ampere-hour

(Ah) you need to connect them parallel.

This

means if you connect three 3.6V

battery

in parallel you get 3.6V but at 6.0 Ah. So how to

increase

capacity

and

runtime

? Most manufacturers connect the 5

cells

in

series

to get 20 volts.

Then

they connect another set in parallel.

This

way we get 20V while the

runtime

increased to 4.0 Ah. You could add another set in parallel to get 6.0 Ah and so on. 20V

batteries

seem to be the base unit on which other capacities are built.

For example

, a 20V Max with 5.0Ah is usually a 5S2P configuration. Here there are 5

cells

in

series

and 2

cells

in parallel.

This

means a total of 10

cells

arranged in two sets of 5. If you need a 40V Max at 2.5 Ah

then

simply change the configuration to 10S or 10

series

. The Anomalies that affect

Battery

Capacity

In real working conditions parameters like temperature - too hot or too cold. Environmental conditions

such

as vibrations, etc. affect the Ah and

voltage

. As these conditions are inevitable at a job site manufacturers set a better expectation by listing a lower rating.

For example

- 18-volt nominal

instead

of 20V Max. There are advancements and innovations in

battery

research. People play with the chemistry and physics of the

battery

. They tweak and tinker with words like cathode, anode, and electrolytes. And you begin to see the difference between impedance, resistance, and other fun words to get better performance. And suddenly an 18 volt and 3 Ah

battery

can deliver 4 Ah and even 5.

Batteries

from different companies deliver different performances.

This

is due to different safeties, better housing designs, and electronic controls. The change in wiring configuration adds more

power

,

ampere-hours

, etc.

Brushless

Motors

on Cordless

Drills

A

drills

motor

is designed to convert electrical

energy

into mechanical

energy

. A

brushless

motor

does not have a brush.

This

elimination of the brush from the

motor

allows more area for a larger

motor

. As there is no friction the

motor

and the

tool

run cooler. The working principle of brushed and

brushless

motors

is similar. The windings on the

motor

become energized. A temporary magnetic field is generated that repels

/

attracts the permanent magnets.

This

magnetic

force

turns the shaft and allows the

motor

to do

work

. In the case of a

drill

, it would be boring a hole. In the case of a driver, it would be turning the screw. As the shaft turns the electric current is routed through different sets of windings of wire.

This

maintains the electromotive

force

of attraction and repulsion and the motion of the

motor

continues. The benefits of

brushless

DC

motors

are improved performance and efficiency. There are little mechanical wear and increased

torque

per watt. The

tool

is more efficient due to higher

torque

to weight ratio. As there is less wear the

tool

is low maintenance. The

tool

has a longer lifespan and quiet. There is no commutator, ionizing sparks or brush erosion.

Besides

the electromagnetic interference (EMI) is nearly eliminated. These

tools

are

also

smaller, compact and

energy

-efficient. The current is regulated by the

circuit

board

instead

of being delivered directly to the

tool

. The

tool

senses the resistance and draws only that much current required to do the

work

. Essential Features on The Best 20V Cordless

Drills

The features to look for on a cordless

drill

are...

Voltage

- The more the

voltage

the more powerful is the

drill

. There are light-duty

drills

(6 - 12V) for small jobs around the house. There are general purpose

drills

(12 - 18V) for driving and drilling works and some heavy

work

.

Lastly

, the heavy-duty

drills

(18 - 24V and sometimes 36V) can be used for construction and heavy works like hammering, etc.

Torque

- As

this

is a

drill

and driver

tool

it should have a turning

force

to make holes or turn a fastener.

This

turning

force

is called

torque

. It is indicated in Newton-meters (Nm) or Inch-Pound (in-lbs.). Most

drills

are made

such

that they can handle plastics, wood, drywall, etc. Harder materials like concrete, metal and other hard surfaces need less speed and more

torque

. To

work

on harder materials, choose a

drill

with a

torque

of 46Nm or more.

Power

(UWO) is a standard for measuring the maximum

power

of the

drill

. It is derived from

torque

and speed.

Thus

, the higher these values the higher the

torque

. Drive

Motor

-

Brushless

motors

have

circuit

boards that help modulate the current,

torque

,

power

and

ampere-hours

. They are quiet and efficient, too. Features

such

... Chuck size - There are 1

/

4-inch, 3

/

8-inch, and 1

/

2-inch chucks. The chuck size determines the type of

drill

bits the

tool

can hold.

Batteries

- The

battery

technology had advanced by leaps and bounds. Li-ion

batteries

with chips carry algorithms that help in the efficient use of

power

. Ensure you have an extra

battery

.

This

way while one is down and charging you are working - using the other.

This

improves your efficiency and eliminates downtime. Speeds -

Drills

can have dual speeds or variable speeds on them.

This

allows you to

work

on various materials - hard and soft. Charger or Charging station -

work

on the principle of alternating magnetic fields. There are

voltage

changing

batteries

available that let you run the

tool

according to

power

usage. Grip - As you are going to be working long hours.

Besides

, you want to do a precise job. Look for a

tool

with an ergonomic design and rubberized non-slip grip. Combo Kits - Many manufacturers offer kits that have a

drill

and driver. Some may have a hammer attachment while others may carry bits. It is always prudent to pick the

tools

of your trade as a set as

this

ensures you have the right sizes.