Power tool batteries: Past, Present and Future!
The different types of battery, what they’re used for and how they work.
Basic battery science and history.
There are actually quite a few battery types in the world and they work in much the same way. They’re in two parts; a cathode (positive pole), an anode (negative pole), with an energised liquid (an electrolyte, usually an acid) floating around both poles. When the circuit is activated the energised liquid wants to get rid of its charges, this creates a current of electrons from negative to positive, creating electricity from the positive electrode.
The most basic form of this was discovered by Alessandro Volta; which is where the word Volts is derived from. Volta experimented using sulphuric acid, copper and zinc to create the first batteries. This developed over time.
The first mass produced commercial batteries (which are still used today) were Lead acid batteries, developed by Gaston Planté consisting of a Lead anode, a Lead Dioxide Cathode and sulphuric acid as the electrolyte. The good thing about this type of battery was that it could be charged quickly and could be recharged after its energy was depleted.
Around 1900 the first alkaline battery (NiCad – Nickel Cadmium) was created by Waldemar Jungner another battery still used today. It was commercialised in 1910 and is still used today to power tools and household batteries today.
In the late 1980’s the first Nickel Metal Hydride (NiMH) batteries were produced as a substitude for the NiCad battery. These newer batteries had a greater charge and lasted longer than the older NiCad battery, they were also not as toxic to the environment. Used for much smaller components, computers and electronics.
The newest innovations in batteries are Lithium, Lithium Ion and finally in the late 1990’s the Lithium polymer battery (Used in today’s mobile phones.)
So how does this help with your battery?
Well, lets take them in order, of discovery and the drawbacks of each.
The Lead acid battery.
This battery is generally pretty heavy, and can be dangerous is overcharged or charged wrongly, boiling the electrolyte! The charge held is much less than other newer, more developed batteries like the NiCad. But it can be recharged to it’s former charge levels, however will dissipate from the solution over time. It’s a reliable performer, especially in it’s newer gel form.
The NiCad battery.
The greatest factor controlling this battery’s life-span is heat. If you purchase a new drill with a NiCad battery you will have lots of uses out of it. However, you will discover that if you recharge the battery while it’s hot, the battery won’t charge as effectively. This will become a cycle of reduced effectiveness over time. This can be described as “battery memory effect”; the battery doesn’t charge to the capacity at factory and gradually reduces over time. This effect is also induced of overcharging the battery!
Sometimes the battery can be “restored” by the use of a diagnostic charger, a deep charge then discharge cycle or by being put into a freezer and then charged.
The NiMH battery.
Sudden drop off of power rather than a slow drop off with NiCad. Temperature can not be subzero else the battery can be damaged. However, this battery is very good for discharging high amounts of energy if needed over a long period of time.
The Lithium, Lithium Ion and Lithium Polymer batteries.
The biggest pro for this battery is its capacity, up to 50% higher than the NiCad battery of equal size. It can be recharged at any point in it’s battery capacity without any adverse effects. However because of the battery’s internal resistance it can not deliver a high yeald of energy quickly in the same way NiCad and NiMH batteries can.
Other good points are the Lithium polymer battery can be moulded and is very versatile with it’s size delivering constant charge throughout its life.
The future…And what’s likely to be powering your drill within the next 20 years.
Yes, a form of graphite made of honeycomb sheets is at the center of this battery. It’s in development and could mean a revolution is battery efficiency, size and durability. This means future batteries could be miniturised to nano proportions. Companies are already looking into using graphene for electric car batteries, giving them a 500 – 600 mile range before needing to recharged.
Yep, foam. You read that right. Using a copper foam substructure a company called Prieto has develped a battery that is much more durable, has a higher capacity and is much smaller than anything before it.
This battery has 40 times the capacity of a similarly sized Lithium Ion battery! Using Aluminium, air and water! Believe it or not, these batteries will be released in 2016 for commercial use. So could be running your mobile phone within the next 5 years if developers get their hands on it and developing the battery.
So watch this space!