What types of batteries are there?

According to the Ecolec Foundation, created by the National Association of Manufacturers and Importers of White Line Appliances (ANFEL) and the Spanish Association of Small Appliance Manufacturers (FAPE), one of these batteries has the capacity to contaminate 12,000 liters of water.

The composition of alkaline batteries is different: They are made with zinc and manganese dioxide. In this case, the electrolyte is potassium hydroxide. For this reason, its performance and duration are higher than those of a saline battery. It is recommended that they be kept at a temperature below 25 ºC, since heat accelerates chemical reactions, decreasing their power over time. However, it is also not advisable that they be stored in the refrigerator. Due to their characteristics, their use is usually reserved for devices that consume a lot of energy or that are used regularly, such as the control of a remote control car or a video game console.

Below is a table with the most common types of alkaline batteries.

According to the Ecolec Foundation, an alkaline battery can contaminate 167,000 litres of water.

Finally, we will talk about lithium batteries. We would like to remind you that we are listing non-rechargeable batteries. Lithium batteries have a low self-discharge and have greater resistance to extreme temperatures, from sub-zero temperatures to 70 degrees. There are several compositions, such as lithium-iron disulfide, lithium-thionyl chloride and manganese-lithium dioxide.

Rectangular batteries

There are far fewer appliances that use rectangular batteries. Their voltage is higher than 4.5 V. One of the most popular batteries of this type is the pouch battery, which is used in school experiments. As in cylindrical batteries, there are saline, alkaline and lithium batteries, with the same properties. This table shows the most common.

Button batteries

They are the smallest batteries. Their performance is highly optimised: They have a high energy density, their discharge is less than 1% per year, they are very economical, their voltage discharge is uniform, they are very stable in the face of temperature changes and do not overheat. That's why they have a lot of versatility and numerous applications. They are usually used in watches, hearing aids, computers, medical devices and pacemakers. According to their composition, they can be classified into alkaline, lithium, silver oxide and zinc-air (those usually used by hearing aids, which have a tab to facilitate their installation).

There is a wide variety of types of button batteries, so it is necessary to follow the manufacturer's instructions to find the right battery.

Despite their size, they are capable of contaminating about 6,000 litres of water, according to data from the Ecolec Foundation.

Batteries

We must clarify the difference between a cell and a battery.

Difference No. 1: A cell's charge will deplete and it can't be recharged, unlike a battery which, if connected to electric current, is recharged.   It must be stressed that cells should never be recharged and that doing so can pose serious dangers.

Difference No. 2: A cell will always hold its charge if not in use, unlike a battery, which tends to lose its charge over time.

Rechargeable batteries

This type of battery is usually more expensive, but having the possibility of recharging implies savings in addition to reducing the amount of waste that is generated. Let's talk about the most common rechargeable batteries.

NiCd

Rechargeable nickel-cadmium batteries have a poorly optimised performance, since their recharge usually presents problems (the memory effect, with each recharge the voltage or capacity is reduced, gradually hindering the use of 100% of its energy) and it has cadmium in its composition, which is a very polluting element. For these reasons, they are used less and less, despite the fact that a priori they have a greater number of potential recharges than other rechargeable battery models.

NiMH

They are rechargeable nickel-metalhydride batteries, with high energy density. In addition, the memory effect has little impact on this model. On the other hand, they have a higher self-discharge rate than NiCd rechargeable batteries, so they are indicated for devices that have continuous consumption and not intermittent or sporadic.

Keep in mind that these rechargeable batteries have a low self-discharge version, know as LSD-NiMH, which offset this issue.

These types of batteries must be recharged with care, since their charging speed is low and they tend to overheat. Temperature changes can affect their performance. Therefore, they have to be recharged in a device capable of identifying the maximum load and stopping the process, otherwise the overheating could cause the electrolyte to escape.

Li-ion

This denomination refers to rechargeable lithium batteries, such as the ones in mobile phones. Due to their high energy density, small size, low weight and low rate of self-discharge, they are versatile and their use in mobile phones means that more technical improvements are being developed every day in this regard. However, their manufacturing process is more expensive and their charge cycles still have a high margin of improvement compared to other rechargeable batteries.

The following table gives you at a glance the main characteristics of rechargeable batteries.