When we’re out and about, what’s the worst thing that can happen? Of course, running out of phone battery! It’s a big deal because almost everything we do today—navigation, shopping, payments—depends on our phones. Without one, nothing is convenient.
Luckily, power banks have come to the rescue. Today, power banks are nearly essential for every outing, especially as smartphones continue to add more features, which in turn drain the battery faster.
However, sometimes we notice that power banks heat up during use, which can be a bit worrying. We might even start to wonder if there’s a problem, or worse, if it could explode.
In fact, there’s a little “guardian” inside the power bank—a thermistor. It acts like a vigilant sentry, constantly monitoring the power bank’s temperature. If the temperature rises too much, it immediately activates a protective mechanism to ensure safety and prevent accidents.
What is a thermistor?
A thermistor is a type of temperature sensor whose resistance changes with temperature. There are two types based on the temperature-resistance relationship: Positive Temperature Coefficient (PTC) and Negative Temperature Coefficient (NTC) thermistors.
These resistors are small, responsive, and highly accurate, making them ideal for use in a wide range of temperatures. They’re commonly found in household appliances like refrigerators, air conditioners, microwave ovens, and printers, where they help measure and control temperatures.
Why is a thermistor useful in a power bank?
The core component of a power bank is the lithium-ion battery, which generates a lot of heat during charging. If the temperature becomes too high, the battery could decompose, potentially causing a short circuit or even an explosion.
This is where the thermistor comes in. It continuously monitors the battery’s temperature, and if it detects excessive heat, it triggers a protective mechanism that cuts off the circuit to prevent overheating and potential danger.
However, not all power banks are equipped with thermistors. So, when buying a power bank, it’s important to choose a high-quality, reliable brand. Don’t be tempted by cheap, low-quality options. After all, safety should always come first. Opt for a trustworthy power bank to avoid unnecessary risks.
This article is provided by JYH HSU (JEC) Electronics. JEC is a research, development, production, and sales-oriented company specializing in manufacturing and selling various electronic components such as capacitors and resistors.
Post time: Jul-08-2025