Advice on how to handle LiIon cells
Tip 1: ALWAYS charge cells fully BEFORE starting built battery pack
This protects you against the flow of equalizing currents. Our cells are not aligned, they come in a different state of charge. If you try to connect cells with different voltages, you can start a fire. Therefore, the cells should always be fully charged first with the appropriate charger for 18650 cells (e.g. Litokala Li-400, Li-500, description 3100 and many others). The cells charged to 4.2V can be safely connected together to form a ready package
Tip 2: Get a soldering station
There is nothing worse for cells than soldering them with a weak resistance soldering iron. Buy the cheapest soldering station with a power of at least 60W at auction portals. This will allow you to solder the plates or wires to the package as quickly as possible and will protect the cell from overheating and, consequently, damaging it.
Tip 3: NEVER throw cells
Take care of the cells and don't drop them on the floor. The cells have very delicate cores. If a cell falls from the desk to the floor, it may be damaged internally and this defect will reveal itself after a few weeks, leading to the discharge of one section to 0V. If any link fails - do not use it and treat it as untrusted
Tip 4: NEVER discharge the cells with the maximum current stated in the datasheet.
The catalog note, referring to the maximum currents, covers work for 1 cell. at a temperature of 25 degrees. In each packet there are many cells that heat each other and this will lead to a quick damage to the battery. Safe maximum current for cells operating in a package is always about 50-60% of the current from the note. So, for example, for the LG MJ1 cell, the note informs about the maximum current of 10A. This means that by discharging the cells in the package, the maximum current drops to 5-6A. If you do not follow this rule - the battery will work 30 charges and you will have to build another ...