In this post I have explained what are gel cell batteries and also learn how to build a specialized charger for charging a gel cell battery, with full calculations. The proposed circuit works in two modes: it starts charging a discharged gel cell battery with constant current, until the full charge voltage is reached across […]
Newly Updated Circuit Projects:
Series 2S, 5S Li-Ion Cell Charger using BQ7718
This BQ7718 series 2S to 5S series Li-Ion cell charger is designed to monitor the voltage of each of the li-ion cells independently, with reference to an internally set reference level. As soon as any of the cell voltage tends to go above the reference level, it triggers an internal delay timer. This delay timer […]
3 LED Battery Level Indicator Circuit
The proposed 3 LED battery level indicator can be typically used for monitoring a 12 V lead acid battery charge level, through 3 distinct LED illumination. The entire circuit is built using just a couple of BJTs , a few zener diodes, resistors and LEDs. Different Ways to Check Battery Voltage A hydrometer is perhaps […]
EV Wireless Battery Charger Calculator Tool
This calculator helps estimate resonant frequency or compensation capacitor for a wireless EV charging primary coil. It is for first-step design and learning, not final tuning… Calculator by homemade-circuits.com EV Wireless LC Resonance Calculator EV Wireless LC Resonance Calculator Calculate: Resonant Frequency (Hz)Capacitance (µF)Inductance (µH) First Value: Primary Inductance µHCapacitance µFFrequency Hz Second Value: Primary […]
Make this EV Battery Charger Circuit
In this post I will explain how to build and test a homemade yet very professional looking high power EV battery charger transmitter circuit using H-bridge fixed-frequency AC inverter topology, driving a series-resonant LC tank. I will also explain how to build a complementing EV charger receiver circuit for receiving the charging current from the […]
Wireless Li-Ion Battery Charger Circuit
Charging batteries through inductive wireless charging is one of the applications that’s becoming very popular and getting appreciated by the uses. Here we’ll study how to make a wireless Li-Ion battery charger circuit using the same concept. Any electrical system which involves wire networks or cables can be very messy and cumbersome. Introduction Today the […]





