The motor vehicle sector is one of the few areas that have benefitted from the tech advancements. Long ago, starting a vehicle wasn’t easy as it’s is today. In that era, ignition was done by a hand crank as opposed to the recent start/stop technology. The crank would provide the car’s engine with sufficient compression to fire off the cylinder.
Often, the flywheel wouldn’t carry on to the next firing, thus forcing the driver to crank the engine now and then. It must have been a hell of a task. Thanks to innovation, today we’ve electric cars and which run on batteries. This car’s batteries are tasked with igniting, as well as, run the vehicle.
How are electric car batteries made? Electrical car batteries are usually made using a step-by-step procedure to come with every working component. Like any other car battery, an electric car battery comprises one or more electrochemical cells.
Each cell contains electrodes or two-half cells. One of the half-cells is called the negative electrode and has plenty of negative electrons. The other half cell is termed as the positive electrode and has a deficiency in electrons.
The two halves are joined using a cable, thus allowing the flow of electricity which is tapped to perform tasks such as running a car. To understand this functionality, I’ve to dig deeper and explain the various areas surrounding the electric car batteries.
Components of an Electric Vehicle Battery
As stated earlier, an electric car battery comprises positive and negative electrodes. The negative electrode in a Li-ion cell, for instance, is made of graphite or carbon. The positive wire is made from metal oxide. In between, there is an electrolyte which is made from an organic solvent of lithium salt.
Today, you will find various battery brands in the market. The truth is that every battery is made using a similar or related procedure. The typical process of building car batteries for electric vehicles starts by coming up with the battery grids. Battery grids are the components responsible for conducting electrical current while providing a structure for the active material to adhere to.
Once the grids are ready, a paste of lead oxide, water, and sulfuric acid is poured on either side of them. An expander material is applied to the grids to create the negative plates.
The material comprises powdered sulfates. The fully pasted grids are then taken through a curing process which takes 2-4 days. The process takes place in a controlled environment and is aimed at binding the paste at the grids.
Once the paste is wholly bound to the grids, the grids are stacked alternately with separators in between the negative grids and the positive grids. As their name implies, the spacers help separate the plates, thus reducing the chances of short-circuiting during the current flow.
Once the grids/cells are correctly arranged, they are placed into a battery case. The top cover is sealed either heat sealed or placed temporary based on the battery model. The battery is then filled with the primary electrolyte and then given a formational charge.
After it’s charged, the sulfuric acid (electrolyte) is replaced with a higher strength acid. Later on, the battery is appropriately sealed, labeled, and checked for quality before being released to you the user.
Types of Electric Car Batteries
Although many manufacturers of electric vehicles utilize a kind of electric batteries, there are many other models that you ought to know.
1. Lead-Acid Batteries
Lead-acid batteries were used early on electric cars and are found today on petroleum driven vehicles. These battery models can be designed to be high power and are quite affordable as opposed to the other electric vehicle batteries (EVBs).
Unfortunately, these battery models have a poor cold-temperature performance and a short lifespan. The fantastic thing is that efficient lead-acid batteries are being made. But, these new models are being released targeting a specific line of electric-drive cars.
2. Nickel Metal Hydride (NiMH)
As compared to lead-acid batteries, NiMH models are considered to be powerful. These battery models can have up to double the specific energy found in the lead-acid battery. Cars using NiMH batteries are somewhat lighter and thus a reduced cost of operating the BEV running in this particular battery.
Also, NiMH batteries are known to have higher energy density. As a result, these types of cells tend to take less space in your vehicle. However, these battery model are known to have a various drawback. For instance, a NiMH battery is said to have a lower charging efficiency.
Besides, the battery has self-discharge issues of up to 12.5 percent on average temperatures. As a result, the self-discharge problem makes this battery model unsuitable for hot regions. In return, the downsides have affected the use of NiMH batteries in most electric vehicle’s manufacturers.
3. Lithium-ion Batteries
Many platforms argue that the lithium-ion (Li-ion) batteries are the perfect batteries for electric cars. Well, the statement is somewhat true as there are many kinds of Li-ion cells in the market today. Despite the many options, vehicle manufacturers focus on models that have fantastic longevity.
As compared to the other EVBs, Li-ion offers many benefits. First thing first, this line of battery has a super-amazing specific energy and energy density. As a result, it remains a perfect option for many vehicle models. Also, the Li-ion cells have a self-discharge of five percent, which is quite lower as compared to that of NiMH, which is 12.5 percent.
One disadvantage of owning this battery is that they are expensive. Of course, with all the benefits, you don’t expect it to come cheaply. Not long ago, I also heard news about Tesla Model S, exploding because of the Li-ion battery.
Well, the Li-ion battery model has issues with fluctuating charges or damages which can cause a fire. The good thing is that vehicle manufacturers have made significant moves aimed at improving the safety of vehicles running on Li-ion batteries.
4. Zebra
Zebra or the sodium battery as termed by many people, relies on molten chloroaluminate sodium to act as the electrolyte. Many platforms refer to the action as ‘hot salt.’ A zebra battery model has a specific energy of 120Wh/kg and a considerable series of resistance. The zebra EVB requires some heating for use.
As a result, it’s suitable for cold weather conditions. This battery model can offer a few thousand charge cycles and thus favorable for a safe environment. Zebra battery models have a poor power-to-weight but have still been used in modern commercial vehicles.
7 Things to Consider When Buying an Electric Vehicle Battery
1. Size
Size does matter when it comes to picking the right battery for your electric vehicle. By digging shallow, you will realize that batteries are categorized based on length, width, and height. You must, therefore, check to confirm the actual size needed for your car from the manual.
Besides, you can consult with your mechanic to be sure that you get the right size for your vehicle. A perfect option should fit perfectly in the battery compartment, thus reducing the damages or complications that may arise from the vibrations.
2. Freshness
Like in groceries, you need to get your battery fresh. The battery’s freshness is usually indicated by a letter code which comprises of a number and a letter. The figure stands for the year while the letter dictates the month. I believe that you shouldn’t choose an EVB that six months older than the date of manufacture.
3. Capacity
How far can the battery run a car? Well, this is one question that you need to ask yourself before you invest in any EVB. As you’re aware, the battery’s main task is to power up the engine. Therefore, you require that one battery that can perform the job without any complications. So, you must pick an array that meets your daily vehicle use.
4. Maintenance
EVBs are quite expensive. The cost can even go higher when maintenance is put in the picture. When choosing the right battery for your electric vehicle, you must, therefore, consider the maintenance cost.
A suitable option should be the maintenance-free type of cell. These maintenance-free batteries are usually sealed. Also, their electrolyte can run throughout the life of the battery. This, therefore, means that you won’t have to incur the replacement cost.
5. Warranty
Like any other commodity in the market, car batteries do have warranties as well. When picking your car’s battery, it’s advisable to have its warranty into consideration. Car batteries do come with varying warranties.
You should choose a model that has the most extended warranties on the list. You can know the importance of a battery’s warranty until it breaks down and has no warranty at all.
6. Type/position of terminals
The location of the positive terminal is vital as it impacts the polarity of the car. Say, for instance, if the positive terminal comes into contact with the car’s metal parts, chances of shorting are high. Unless you don’t mind an accident, you must consider the position of the positive terminal. A perfect battery should have its terminals adequately labeled and placed to prevent accidents.
7. Lifespan
Every cell has a different lifespan. Some have shorter, while others have longer lifespans. The battery’s lifespan is affected by many factors among them the manufacturer. Therefore, when choosing the right battery for your electric vehicle, ensure that you consider the lifespan.
Your ideal choice should have a favorable lifespan. In other words, the battery should be in a position to serve you over a considerable amount of time. (This article is helpful for the longevity of an electric car battery, if you like to know more).
Sources:
1. Batteries for Electric Cars – BCG
2. How do electric car batteries work – Financial Times
3. Types of Batteries Used for Electric Vehicles – Stanford University
