Use USB-C lithium battery Charging Module 3S 12.6V 4A & Heating Problem Fixing

Fixing Overheating in a 2S/3S/4S LiPo Charger by Upgrading the Inductor

I was using a multi-cell 2S/3S/4S LiPo charger that steps up voltage via a boost converter, but I noticed it was overheating during operation. After some troubleshooting, I identified the inductor as the main issue—it was getting extremely hot, leading to reduced efficiency and potential long-term failure.

Understanding the Problem

The inductor in a boost converter plays a crucial role in energy storage and transfer. If it's undersized or has a low saturation current rating, it can overheat, causing power losses and inefficiency.

The charger operates at the following voltages:

8.4V for 2S (7.4V nominal)

12.6V for 3S (11.1V nominal)

16.8V for 4S (14.8V nominal)

Since this circuit boosts the voltage, it requires an inductor capable of handling higher currents without saturating.

Inductor Upgrade to Fix Overheating

To resolve the issue, I made the following improvements:

Increased the Inductor’s Current Rating

The original inductor was likely undersized, causing it to heat up under load.

I replaced it with an inductor rated for a higher saturation current (e.g., from 3A to 5A or more) to ensure it could handle peak currents without overheating.

Used a Larger Inductor Value

Increasing the inductance (e.g., from 4.7µH to 10µH) helps reduce ripple current, improving efficiency.

A larger inductor also reduces switching losses and stress on other components.

Upgraded to a High-Efficiency Inductor Type

I selected a Sendust inductor with low DC resistance (DCR) to minimize power loss and heat generation.

Results After Upgrading the Inductor

Significantly lower heat generation—the charger now operates at a much safer temperature.

Improved efficiency—better power conversion with less energy wasted as heat.

Stable voltage output—the upgraded inductor ensures the charger delivers consistent voltage without excessive ripple.

Increased longevity—less heat means reduced stress on the components, increasing the module’s lifespan.

Final Thoughts

This simple inductor upgrade fixed the overheating problem and made the charger much more reliable for continuous use. If you're experiencing similar issues with LiPo chargers or boost converters, checking and upgrading the inductor can be an effective solution.

#lithiumbatterycharger #3Sbattery #lithiumbattery #lipo #batterypack #batterypackcharger