Lithium-ion cells (Li-ion batteries)

Popular, universal Li-ion batteries are cylindrical cells of the 18650 type, which can be found in many consumer devices powered by single cells (such as e-cigarettes, flashlights) or in the form of closed packs (power banks, batteries for power tools, laptops or electric bicycles). They are even used to power Tesla electric sports cars and energy storage for renewable sources, where the number of batteries in one pack often exceeds several thousand pieces. Compared to popular nickel-metal hydride batteries, however, there are several important aspects that every user of these cells should be aware of.

Li-ion batteries have a nominal voltage three times higher compared to Ni-MH cells (approx. 3.4-3.7 V), but they are also much more expensive to produce. They have a higher density of stored energy, making them smaller in size and much lighter than their nickel-metal hydride counterparts. Like rechargeable batteries, Ni-MH batteries have a very flat discharge characteristic.
They are also characterized by a low self-discharge rate of no more than 3-5% per month and greater reliability.

The device must be adapted to Li-ion rechargeable batteries – they are not a direct replacement for Ni-MH batteries or alkaline batteries. Li-ion batteries can be divided into protected batteries (such a battery has an integrated electronic system that protects the cell from improper use) and unprotected batteries (such cells are very 'fragile', the process of discharging and charging such a cell should be very carefully controlled and it should be particularly protected against short circuits).

Bearing in mind the requirement of special treatment of 18650 type cells, they should be charged in high-quality processor chargers from well-known manufacturers. The most advanced representative of chargers designed to charge 18650 cells is everActive LC-2100, which allows you to charge 1-2 pieces of cells in an optimal, safe and automatic way. It has two independent charging channels and the ability to choose the current with which the cells are charged. In addition, the LC-2100 charger has a capacitance (discharge) test and a unique internal resistance test, which allow you to accurately assess the condition of each individual cell and determine the appropriate application for it.

The batteries themselves should also be chosen rationally. We recommend choosing cells only from proven manufacturers with an established position on the market. One The initial criteria for assessing the quality of a battery may be its capacity. Here, as in the case of Ni-MH cells, you can encounter an unfair practice of significantly (even by 1000%!) overestimating the value of the capacity given on the battery label/packaging. It should be borne in mind that the maximum technological capacity achieved in the most expensive, Japanese 18650 cells is about 3500 mAh.
However, the most popular are cells with a capacity of 2000-2600 mAh – even these will be a much better choice than buying a "bargain" battery with an incredibly high capacity. Such batteries are often offered as 4000-10000 mAh, but in reality they have capacities no higher than 1000 mAh. At the same time, they are potentially dangerous to use. When buying such unreliable cells, you also have to take into account the fact that they are often not brand new – they may come from the disassembly of used batteries, e.g. for laptops. Copyright © Baltrade