Did you know?
For many years, nickel-cadmium (Ni-Cd) batteries had been
the only suitable choice for portable equipment from wireless communications to
mobile computing. Lithium Ion and nickel-metal-hydride (Ni-MH) batteries only emerged
in the early 1990s, fighting nose-to-nose to gain consumers' acceptance. Today,
lithium-ion is the fastest growing and most promising battery chemistry!
Paying for what it's worth
During the last decade, cordless tools have expanded in
voltage and applications to become the primary tools used in residential and
commercial job sites. The introduction of cordless power tools saw the demand
for stronger batteries able to deliver the punch comparable to a corded one.
Li-ion battery technology then sought its breakthrough as the solution to this
idea. Li-Ion batteries are therefore generally more expensive than their
counterparts made up of Nickel-Metal Hydride or Nickel Cadmium. But why? - Let
us find out.
Complexities in
manufacturing process
Li-ion batteries have a special in-built circuitry to manage and protect the battery from damage caused due to overcharging or
undercharging. It is akin to putting your cell to charge overnight and
over doing it or continual usage despite charging when battery is low.
Smaller production
Li-ion batteries are manufactured and produced in much
smaller quantity than Ni-MH or Ni-Cd batteries. Higher production costs lead to
smaller quantity produced.
Exclusiveness of chargers
for Li-ion batteries
Chargers are sophistically designed to suit the different
shapes and sizes of Li-ion batteries in order to facilitate and monitor the
charge process. This also means that there is no 'one-size fit all' universal
charger that could perhaps ease the cost of these batteries.
Knowing the Differences
Li-ion, Ni-MH and Ni-Cd batteries each have their own
advantages, knowing their strength and understanding what they have to offer
can influence your choice of batteries in getting the job done. Li-ion
batteries typically comes in three formats - pouch, cylindrical and prismatic,
of which cylindrical forms lend themselves to powering medium-sized portable
devices, such as power tools. Let us now look at the advantages independently.
Sample image (Li-ion) - Makita 18V/1.5Ah
Li-Ion Battery
Advantages of Li-ion batteries
- High energy density - potential for yet higher
capacities.
- Does not need prolonged priming when new - One
regular charge is all that's needed.
- Relatively low self-discharge - self-discharge
is less than half that of nickel-based batteries.
- Low Maintenance - no periodic discharge is
needed; there is no memory.
- Specialty cells can provide very high current to
applications such as power tools.
Sample image (Ni-Cd) - Makita 14.4V/2.0Ah
Ni-Cd Battery
Advantages of Ni-Cd batteries
- Charging with very high
currents does little or no damage to the battery allowing very fast charging
(15 minutes)
- Can provide very high
currents, suitable for high-drain application such as power tools.
- Capable of working in
extreme weather conditions - work well in cold weather.
- Longer shelf life.
- Can withstand 400-1000
cycles with minimum capacity loss.
- Relatively safe.
Sample image (Ni-MH) - Makita 14.4V/3.0Ah
Ni-MH Battery
Advantages of Ni-MH batteries
- High energy density
compared to Ni-Cd - up to 3600 mAh (milliamps hour) or 3.6Ah per cell compared
to 2400 mAh or 2.4Ah in Ni-Cd.
- Cheaper than Li-Ion batteries.
- High shelf life.
- Can withstand 500
cycles with minimum capacity loss.
Techies Technical Data
Making the right choice!
Now that you have a better idea
of these batteries, remember when you are choosing a power tool battery, you
should be looking at a battery's run
time, life cycle, volts and amp-hour rating.
Run time quite simply means the amount of work a tool can do before
its charge runs out.
Life cycle is how many times the battery can be recharged during
its life time.
Volts (Power) will determine work output of the tool, the higher
the volts, the higher the power. That means more torque for driving screws or
mitre sawing, more speed for jigsawing and sanding, more hammer action for
impact driving.
Amp-Hour Rating:
The higher the Amp-Hour rating the longer the battery lasts - note that power
tool batteries of the same voltage will often have different Amp-Hour ratings.
As we can see, clearly there are many different options to
choosing the right battery type. Therefore, it is imperative that you come
prepared with knowledge that will help you make the right decision to suit your
situation should a purchase need arise. Be sure to choose one that does not
under or over perform what is required.
Check it out as Andrew from KMS Tools explains why Lithium Ion batteries in power tools are better than Ni-Cad batteries - http://bit.ly/ZKOWrs
