Reverse current is a common issue in battery-powered circuits where current flows back into the battery when the power source is disconnected or reversed. This can damage batteries, lead to overheating, or even cause a short circuit. Fortunately, you can prevent reverse current easily using a Schottky diode or a P-channel MOSFET in your circuit.
The Problem :
When a battery is connected to a load, any fluctuation in power or reverse polarity can allow current to flow backward into the battery. This not only reduces battery life but can also damage connected devices.
The Solution :
Schottky Diode: Place a Schottky diode in series with the battery’s positive terminal. The diode allows current to flow only in one direction, blocking reverse current.
P-channel MOSFET: For higher efficiency, use a P-channel MOSFET in the high-side configuration. It offers lower voltage drop and minimal power loss compared to a diode.
Practical Example :
Consider a 12V solar panel charging a battery during the day. At night, if no protection is applied, the battery may discharge back into the solar panel, causing damage. By adding a Schottky diode (e.g., 10A10 diode) in series with the positive wire, reverse current is blocked, preventing damage.
Sample Calculation :
If the solar panel delivers 5A peak current, choose a Schottky diode rated for at least 7A and 20V to ensure reliable operation.
A 10A10 diode (10A, 100V) is a suitable choice.
Product Suggestions :
[Schottky Diodes] Ideal for low-voltage reverse current protection.
[P-Channel MOSFETs]
For high-efficiency reverse current blocking.
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