“Li-Ion batteries (18650 cells) are very widely used in all the electronics gadgets that we use today like mobile phones, laptop, powerbanks, etc. These batteries provide good backup and are a reliable source of power, therefore are also very convenient to use in DIY projects. However, charging these batteries is still hassle as the commercial chargers are quite expensive. Also, a good quality charger is essential for Li-Ion batteries, otherwise the battery life will get degraded soon. A balanced charger does the job well but it is available in higher price range.
So, in this instructable i decided to make a Li-Ion battery charger that can simultaneously charge four 18650 cells together. This charger is very simple to make and performs the work of a balanced charger by stopping the power to the individual cells after the battery gets charged completely.”