Batteries are stronger than cells because they consist of a collection of cells, and are hence used when high amounts of power are required. These cells then undergo certain chemical reactions within the collective circuit of the battery, and a good amount of energy is generated through this process.
Why should you care about the different battery types out there though? Well, given that the need for more efficient as well as more environmentally sustainable energy sources is increasing day by day, a lot of research is going into battery technology, and advancements are coming hard and fast. Which makes this a good time to learn about the different battery types currently out there.
Also, the battery is extremely important when it comes to budget laptops, as the battery is one of the things that is usually sub-par on them. Knowing battery types and how they work will allow you to make a more informed decision on which laptop to go for.
How Batteries Work
First things first, let’s take a quick look at how batteries actually work. Batteries provide and store electrical energy. However, remember that only DC (direct current) can be stored in batteries; AC (alternate current) cannot. The individual cells consist of the following components: the anode or negative electrode that produces electrons, the cathode or positive electrode that is needed to create a potential difference inside the circuit, and the electrolytes that prevent the redistribution of electrons inside the battery; which is a natural tendency. Ultimately, when the battery is switched on, the electrons move from the anode to the cathode, and this is what powers the circuit to which the battery itself is connected.
Types of Batteries
There are two major categories of batteries: primary and secondary batteries; wherein primary batteries cannot be recharged and secondary batteries are rechargeable. Each category has further types, and we will now look at the specifics of each.
Primary batteries cannot be reused because they utilize electrochemical reactions which cannot be reversed. These batteries can exist in different sizes and forms; ranging from AA batteries to coin cell batteries. Primary batteries are usually used for standalone applications, ones where recharging is either impractical, impossible or simply not required. For instance, military-grade devices and equipment use primary batteries; recharging a battery is likely to be the last thing on a soldier’s mind.
Primary batteries consume very low amounts. As a result, the battery can last as long as possible. The most commonly used type of primary batteries is the alkaline battery. These have high energies and are both cost-effective and environmentally friendly. They do not leak even after they have been fully discharged and can be stored for. The only downside to these is that they have a low load current, which means they can only be used for devices that have low current requirements. Think flashlights, remote controls, and portable devices.
The electrochemical reactions in secondary batteries can be reversed by applying the same amount of voltage in the reversed direction. These batteries are rechargeable because the secondary cells in them can be recharged. Such batteries are generally used in scenarios where it would be too expensive or impracticable to use single, non-rechargeable batteries. Secondary batteries having smaller capacity are used for portable devices like mobile phones and laptops, or heavy-duty applications, like powering electric vehicles.
Types of Rechargeable Batteries
Secondary Batteries can further be differentiated between, based on their chemistries. In this regard, we see four types of rechargeable batteries.
In a lithium-ion battery, the materials used for the electrodes serve as a host for the lithium-ions which move from the anode to the cathode during discharge and reverse direction during charging. The electrolyte used here is an organic solvent with a dissolved lithium salt. These batteries are used commercially the most, and the average voltage range is 3.0 V when discharged, to 4.2 V when fully charged.
Nickel Metal Hydride Batteries
In a nickel-metal hydride battery, the active components are nickel hydroxide contained in the positive electrode and a hydrogen storing metal alloy contained in the negative electrode. The electrolyte is potassium hydroxide. Compared to the second category of nickel-based batteries, which we discuss next, these have a much higher energy density, both per weight and volume.
Nickel Cadmium Batteries
This is the second Nickel-based battery commonly used, and its active components are nickel hydroxide in the positive electrode and cadmium in the negative electrode. The electrolyte is, again, potassium hydroxide. These batteries can supply very high currents and can be recharged rapidly because they have low internal resistance and excellent current conducting properties. However, misuse could result in a quick, and dangerous, high-pressure rise, so these cells contain a safety valve. They are usually economical because they offer a long service life.
Lead Acid Batteries
Lead-acid batteries are also called small sealed lead acid, or SSLA batteries. They are often called maintenance-free because they work well in poorly ventilated or confined spaces. This is because the valve-regulation in these batteries means that they do not need regular inputs of water to the cells as other, wet lead-acid batteries do.
What to Consider When Buying Batteries
Now that you are well aware of how the different battery types work, there are certain factors you need to consider when it comes to buying batteries. These are as follows.
Energy density will determine how long your device will stay on before it needs to be recharged. Power density determines the kind of device that the battery will work best with. Low power is good for laptops and high power is used for power tools, like solar battery banks.
Safety is important because depending on the temperature you are working at, some battery components can break down and undergo exothermic reactions at high temperatures. In fact, high temperatures can generally reduce battery performance.
Also, consider life cycle durability as well as the stability of the charging and recharging cycle of the battery. Lastly, cost matters. A battery should be both effective and efficient; it should be able to meet your needs without dramatically escalating project cost.
The aforementioned types should help you figure out what kind of batteries you need. In most cases, the casual user will need rechargeable batteries. Primary batteries are only situational, and may be used by you at your workplace, but probably not at home!