mosfet prevents battery damage

Posted on Feb 5, 2014

Sealed-lead-acid batteries, which find wide use in power-electronics products, such as UPS (uninterruptible-power supplies), inverters, and emergency lamps, supply power to the load whenever utility power is unavailable. When you restore utility power, a charger supplies the power to the load and charges the batteries (Figure 1). You can add a dio

mosfet prevents battery damage
Click here to download the full size of the above Circuit.

de to protect a load from current resulting from a reverse-connected battery. The diode, however, won`t protect a reverse-connected battery from the charger circuit. If the charger is on, a potentially dangerous current can flow into a reverse-connected battery. The battery voltage, which normally opposes the charging voltage, now aids it, which lets a higher current flow into the battery. If you add an N-channel MOSFET to the circuit, you can protect the battery from this damaging condition (Figure 2). The MOSFET conducts only when the battery is correctly connected, which lets the battery charge or discharge. In this condition, the transistor gets forward-biased, which switches on the MOSFET. If the battery is reverse-connected, the transistor and MOSFET turn off, thus preventing current flow. This simple circuit provides reverse-battery protection in both charger and battery paths, thereby protecting the battery, the charger, and the load. You can use a microcontroller to measure battery current and make a decision on appropriate action, as well.

Leave Comment

characters left:

New Circuits



Popular Circuits

AVR Microcontroller Digital Clock with ATtiny2313
Basic Multivibrator
Microcomputer-To-Triac Interface Circuit
Interfaces For The Remote-Control Transmitter Circuit
autotronics injector circuit
Water Level Sensor with Arduino Ethernet
Hum Filter Remove AC Line Noise Pre Amp Circuit for Hi-Fi Amplifier Audio Systems
local oscillator
make circuit diagram
ir remote control tester
Overheat Detector Alarm Switch
I burned out some resistors on the circuit board of my Roland
TDA6103Q having a feedback factor of the test circuit
Audio high-pass filter