In this post I have explained a four simple yet a safe way of charging a Li-ion battery using ordinary ICs like LM317 and NE555 which can be easily constructed at home by any new hobbyist.
This lithium battery charger circuit automatically cut off the charging process when the full charge limit of battery is reached (i.e-4.2V) . This circuit also protect our battery from over discharging by automatically cutting the output power when the battery voltage falls below 2.4 volt.
In this tutorial, we are demonstrating a Li-ion Battery Charger Circuit. Li-Ion batteries usually require constant current, constant voltage (CCCV) sort of charging calculation. A Li-Ion battery ought to be charged at a set current level (regulating from 1 to 1.5 amperes) until it arrives at its peak voltage.
What is a battery charger circuit?
The circuit that charges the battery by supplying the charge carrier (i.e-electrons) to it is battery charger circuit. Most of the rechargeable battery has common problem of over charging and over discharging. we need a smart charging solution that protects our battery from over charging and damage cause by over charging.
This lithium-ion battery charger circuit utilizes an LP2931 controller IC. The diode is working as a blocker / current blocker to prevent the current flow back into the IC when there is no voltage on the IC input. The yield voltage can be adjusted with a 50k potentiometer between 4.08V to 4.26V. The circuit gives 100mA of charging current.
The post elaborately explains 3 Hi-End, automatic, advanced, single chip CC/CV or constant current, constant voltage 3.7V Li-Ion battery charger circuits, using specialized Hi-End IC TP4056, IC LP2951, IC LM3622, with battery temperature sensing and termination facility. CIRCUIT DESCRIPTION
Can a 4th Circuit charge a battery?
Also, if you keep the full charge level of the charger at 1V lower than the actual full charge level of the battery, then an auto-cut off will not be needed. So basically, the 4rth circuit is unnecessarily complex, you can actually charge your batteries effectively and safely using any simple CC CV voltage regulator circuit.