Lithium and nickel batteries are the two most popular batteries out there. When it comes to Nickel batteries, there are Nickel Cadmium (Nicad) and Nickel Metal Hydride (NiMH) batteries. Among these two, NiMH is more popular. In this article, we will do a comparison of Nickel Metal Hydride and lithium batteries. It will help you decide which one is best for your application.
Let us get started.
1. Battery Cost
Battery cost is an important parameter that you must consider while selecting a battery. When you compare the price of Nickel batteries with lithium ones, the cost will be more for the lithium battery. The cost will be almost double the nickel battery. Lithium batteries are becoming more popular nowadays. Thus, the cost of the battery is also coming down. But, you must also consider the other costs like the maintenance and operational costs. Many consider only the actual price of the battery and miss these additional expenses.
Nickel batteries drain out faster when compared to lithium battery of similar size. So, you will end up replacing the batteries of your device every now and then. Thus, the effective cost of the batteries will be more. Also, if your device is a power hungry one, the nickel batteries will not last long. The performance of lithium batteries will be better for such power hungry devices.
2. Battery Weight & Size
Certain devices demand lightweight batteries, especially portable battery operated devices. So, you need to go with the battery that offers very less weight. When you compare the weight of a nickel battery with a lithium one, the nickel one will be heavier. If you consider the case of electric cars, they prefer lightweight batteries. A lightweight battery helps to reduce the overall load on the engine. Thus, you can get more mileage for the car. It is one of the important reasons why electric cars prefer lithium batteries.
3. Voltage Output
You can keep both nickel and lithium batteries in series and parallel arrangements. It helps to provide more current and voltage to the circuitry. The standard output voltage of a NiMH battery is 1.2 V. For lithium batteries; the typical output voltage is 3 V. Thus, the output voltage is more for lithium cells. But you will need more alkaline cells to provide the same amount of output voltage as the lithium cells.
4. Energy Density of Battery
The energy density of the batteries is another critical factor. For nickel batteries, the energy density comes in the range of 70 to 100 kWh/m3. For lithium batteries, the energy density comes in the range of 80 to 200 kWh/m3. So, lithium batteries have more energy density than nickel ones. Thus, you will be able to pack more energy inside a lithium battery when compared to a nickel one. It is the reason why you can get higher-capacity lithium batteries in smaller packages when compared to nickel metal hydride batteries.
5. Memory Effect
Nickel metal hydride batteries show a special phenomenon called the memory effect. According to this memory effect, if you do not discharge the nickel battery completely before charging, the energy-holding ability of the batteries will come down. Thus, the overall lifespan of the nickel battery will get reduced. There are no such memory effect issues for lithium batteries.
6. Battery Efficiency
Efficiency is a key factor for any application. You will be looking to run your device at the maximum possible efficiency. So, you must take the efficiency of the battery also into account. Nickel batteries come with an efficiency of around 80 to 85 percent. On the other hand, lithium batteries come at a higher efficiency of almost 95 percent. This higher efficiency of lithium batteries makes it a preferred choice for most applications. It helps to improve the overall efficiency of the device.
7. Battery Chemistry
The major difference between Nickel Metal Hydride and Lithium batteries is in the battery chemistry. Both these batteries come with entirely different chemistries.
There are four different parts to a lithium battery. It uses lithium as the cathode and graphite as the cathode. There will be plastic and polyethylene that act as separators. The electrolyte consists of lithium salts. If you take the case of a nickel battery, it consists of two main ingredients. They are nickel and hydrogen. One more metal will be present inside the nickel battery. In most cases, it will be titanium. It is essential to know the difference in chemistry between these two batteries to know the internal elements.
8. Durability Factor
The durability of the battery is another important factor to consider while selecting a battery. When you consider durability, you need to consider the working temperature of the battery. Under normal temperature conditions, both lithium and nickel batteries show good durability. But under extremely hot weather conditions, the performance of nickel batteries is better than lithium ones. It is one of the reasons why some prefer nickel batteries over lithium ones for devices that operate in extremely hot conditions.
9. Battery Charger
Another important factor regarding batteries is battery charging. In the case of lithium batteries, there are multiple variants of lithium batteries. So, each type of these batteries demands a specific type of charger. In the case of alkaline batteries, they support various types of chargers. So, they have more flexibility when it comes to the charger factor. Even if you misplace or lose the NiMH charger, you can still find a quick solution to charge it.
10. Voltage Depletion Factor
One main advantage of the lithium battery is its zero voltage depletion rate. Unlike nickel batteries, you do not see a lithium charge level reduction. It is one main reason why lithium-ion batteries have a long lifespan.
11. Time to Charge
Another factor to consider is the total time taken to charge the battery. Nickel batteries take more time to charge when compared with lithium-ion batteries. This faster charging time comes with an added advantage. If you use lithium batteries in your device, you can use them for more time when compared with nickel batteries, which take more time to charge. Also, the infamous memory effect is not present in lithium batteries.
12. Compatibility Factor
NiMH batteries come in standard sizes. So, you can use it in the application that supports that support standard-size batteries. Lithium batteries usually come in custom sizes. So, you cannot use it in applications that support standard-size batteries.
13. BMS (Battery Management System) Requirement
It is not mandatory to have a Battery Management System for Nickel batteries. Still, you can keep a battery management system for nickel batteries, as it will not increase the overall cost drastically. But Lithium batteries do need a Battery Management System. It is because of the difference in the charging techniques for both these batteries. In the case of nickel batteries, you need to force the current into the battery for charging. But for lithium batteries, the charging happens in different phases at different rates of current and voltage. So, a battery management system is essential for lithium batteries. It is also needed for the safety of lithium batteries.
14. Safety Factor
If you compare the traditional lithium cells with the nickel cells, nickel ones are found to be more stable. But, the rapid advancement in the field of lithium-ion batteries helped to come up with the new lithium cell technology. This new technology helped to fix all the previous safety concerns associated with lithium batteries. It has made lithium safer. Thus, the new generation of lithium batteries is completely safe to use without any issues.
Now you know the various pros and cons of both nickel and lithium batteries. After going through the detailed comparison, it is quite clear that Lithium batteries do have more advantages when compared to Nickel ones.