Batteries are the energy storage units in several devices we encounter every day. They come in various shapes and sizes. They are commonly found in vehicles, emergency power supplies, mobile devices, tablets, iPads, and many other portable electronic devices. However, not all devices use the same type of battery. Each device has its own specifications and power requirements, and you will need a battery selection guide to choose the right battery for your application. Therefore, this article will examine the considerations to take into account when selecting a battery for your next electronic product design. If you are unfamiliar with batteries, it is recommended that you read this article on battery types and their applications first before continuing to learn about the basics of batteries.
Some factors to consider
When choosing a battery for an application, you must understand the important parameters involved in its operation. The truth about batteries is that there is no ideal battery, and therefore no one-size-fits-all battery form. You should be able to manage the parameters of the battery you choose to use when other parameters run out. For example, if you want the battery to provide a large amount of energy for your application, you should reduce the battery's internal resistance, which can only be achieved by increasing the surface area of the electrodes. Since energy density is compromised to obtain power, inactive components such as current collectors and conductive additives are also improved. You must discard anything to fit another battery into your system to get exactly what you want for your application.
Now, to understand their importance and impact on battery efficiency during maintenance, let's briefly look at each battery parameter.
Rechargeable/non-rechargeable batteries
There may not be much uncertainty in choosing between a primary and secondary battery; you simply need to determine whether you intend to use it once or multiple times. Primary (non-rechargeable) batteries are suitable for occasional applications such as toys, flashlights, smoke detectors, etc. They are also used in products like pacemakers, watches, and hearing aids that cannot be recharged. Secondary (rechargeable) batteries are suitable for applications requiring a standard power source, such as mobile phones, computers, cars, etc. Compared to primary batteries, secondary batteries typically have a higher self-discharge rate due to their rechargeability.
Available space
Batteries include button cells, cylindrical cells, pouch cells, and prismatic cells, and come in various shapes and sizes. Battery size is indeed important for making your computer comfortable and portable. AA, AAA, and 9V batteries are the standard sizes available for portable devices. Lithium-ion batteries (pouch type) are widely preferred in applications with limited space but requiring more power. Button cells can also be considered if power demand is low due to their very light weight and status as the smallest battery type.
System operating voltage
One of the most important characteristics of a battery, calculated based on the electrodes and electrolyte used, is its battery voltage (chemical reaction). A common misconception is that a fully discharged battery will never have 0V in any device. In fact, if a battery reading is 0V, it is likely dead. The battery's output voltage should always be read from its nominal voltage level.
Zinc-carbon and nickel-metal hydride batteries use water as the electrolyte and provide a nominal voltage of 1.2V to 2V, while lithium-based batteries use an organic electrolyte, which provides a nominal voltage of 3.2V to 4V. Most of the device's electronic components operate within a 3V voltage range. If you are using a lithium-based battery, a single cell is sufficient to power the device. Note that the battery voltage will not be constant and will vary between a minimum and a maximum value depending on the available battery power. The minimum and maximum values are shown below for each cell.
If your circuit operates at 5V and is charged with a lithium battery, the nominal voltage is only 3.2V to 4V. In these cases, a boost converter circuit is used to convert the battery voltage required by the circuit to 5V. If your operating voltage is high, such as 24V or 12V, you can use a 12V lead-acid battery, or you can connect multiple lithium batteries in series to increase the output voltage (if high power density is required).
Operating temperature
For example, batteries using aqueous electrolytes cannot be used at temperatures below 0°C because the aqueous electrolyte may freeze below 0°C. Similarly, lithium-based batteries can operate at temperatures as low as -40°C, but their efficiency may decrease. Battery performance can be significantly altered by temperature.
The optimal charging rate for lithium-ion batteries is between 20°C and 45°C. Using lower current/voltage outside this temperature range will result in longer charging times. If the temperature drops below 5°C or 10°C, dendritic lithium plating may form in the electrolyte, which must be avoided by using trick current charging.
Capacity, power and energy
The battery's power determines its operating time. Battery power/capacity is expressed in watt-hours (Wh). This is calculated by multiplying the battery voltage (V) by the amount of current the battery can produce in a given time.
High-power batteries always have the ability to discharge quickly at high discharge rates, such as in applications like power tools or vehicle starter batteries, but most high-power batteries have relatively low energy capacity.
Chemical properties
By then you will know that all the characteristics of a battery generally depend on the chemistry involved. Depending on the chemical methods used, batteries are called lead-acid batteries, alkaline batteries, nickel-cadmium batteries (NiCd), nickel-metal hydride batteries (NiMH), lithium-ion batteries (Li-ion), and lithium polymer batteries (Li-polymer).
Shelf life
Not all batteries are used immediately after development, but they will sit on shelves for a long time before use. The battery's shelf life tells you how long you can leave it idle. With a primary battery, the shelf life is simply a fact because a secondary battery can be recharged once used. A battery might sit idle for years, for example, in a fire alarm until a fire is detected and the alarm is activated. Even if a battery is not used for a long time, it will still retain its output, so please be careful.
