The main feature of this lambda-diode low battery indicator for Ni-Cd batteries is that, the circuit itself consumes almost zero current, until the set low threshold level is reached and the indicator LED is illuminated. This feature makes the circuit very suitable for many low voltage battery operated systems, like radios, watches, timers, alarms, remote […]
Battery Charger Circuits
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 […]
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 […]
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 […]
Simple SCR Battery Charger Circuit
In this post I have explained a simple yet accurate SCR triggered battery charger circuit which can be used effectively for charging all types of battery, which includes, lead acid battery, Ni-Cd battery banks, Li-Ion battery, etc. This SCR charger can be seen implemented in most automobile garages, and is very popular among auto mechanics, […]
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 […]