Do you often encounter such problems? If you suddenly lose the charger for your drone, power tool or speaker, you may find an ordinary charger to charge the device. Does this charging method bring safety risks?
It is directly related to your personal safety, equipment safety and the life of the battery itself, because lithium batteries have their own specific charging methods, and even cause overheating and damage. This article explores identifying and judging which charger is really suitable for your battery, as well as charging alternatives.
Using any charger not specifically designed for your model and specification of Li-Ion battery is extremely dangerous and not recommended.
This is mainly because the potential risks are very high. This is not simply a matter of not being able to charge or charging slowly, but a real safety hazard.
It may permanently damage the battery or break your device; in serious cases, it is very likely to cause the battery to overheat, smoke, catch fire, or even explode. These are not small probability events. Lithium batteries are dangerous goods, so we must be very cautious.
The charging mode of lithium batteries is CC/CV, which requires a very precise and staged charging process.
At the beginning, it needs constant current charging, charging with a stable and appropriate current (this is called constant current, CC for short) until the voltage rises to the charging cut-off voltage, which is like pouring water quickly into an empty cup.
When the battery is almost full, it switches to constant voltage charging. The charger switches to a specific voltage (such as 4.2V for a single-cell lithium battery), and then slowly reduces the charging current until the battery is fully charged (this is called constant voltage, or CV for short). This is like carefully adding water to a nearly full cup, making sure it stops at the mark and does not overflow.
Lithium batteries are extremely sensitive to voltage. Do not overcharge them. You can think of it as a balloon that cannot be over-inflated. If the charging voltage is slightly higher, the lithium battery may also be seriously damaged. Excessive voltage will damage the internal structure of the battery, causing internal short circuits and rapid heating, which is one of the main causes of bulging, smoking and even fire. Therefore, the output voltage of the charger must accurately match the charging voltage required by the battery, without any deviation.
They may be designed for completely different batteries, such as the nickel metal hydride (Ni-MH) or nickel cadmium (Ni-Cd) batteries commonly used in the past. The charging voltage and charging method of these traditional batteries are completely different from modern lithium batteries. In addition, they require trickle charging, but trickle charging is harmful to lithium batteries.
Some chargers are just simple power adapters, which only provide a fixed voltage or current, and cannot match the constant current to constant voltage charging mode required by lithium batteries. It may continuously output a voltage that is too high or unstable for lithium batteries.
If your charger is indeed designed for lithium batteries, but its voltage specifications (for example, it is for a 12V battery pack) and your battery (for example, a single 3.7V/4.2V battery) do not match, then it is definitely wrong and dangerous.
What happens if you use the wrong charger
If you use an inappropriate charger, what dangerous things will happen? The following are the specific hazards.
The most common hazards are overcharging and overheating. As we mentioned before, if the charger voltage is too high, it will keep charging the battery. This will cause the chemical reaction inside the battery to get out of control and the temperature to rise sharply.
It may even lead to an extremely dangerous condition, “thermal runaway”. You can think of it as a fire inside the battery, forming a vicious cycle, the temperature will soar out of control and there is no way to stop it. Once thermal runaway occurs, the battery will become extremely hot very quickly, and then it is likely to emit a lot of smoke, sparks, or even directly catch fire, or explode in extreme cases.
You may also see some obvious signs, such as bulging. This is because the incorrect charging causes abnormal gas to be generated inside the battery, which deforms the outer shell. Sometimes, in order to release pressure, the battery will vent from the safety valve, which is usually accompanied by a pungent odor, and the discharged substances are harmful.
Even if there are no direct hazards as mentioned above, it will definitely cause permanent damage to the battery. The most common is that the battery capacity is greatly reduced, resulting in a decrease in battery life.
It may also damage the charger itself, and excessive voltage or current may also burn out the charging circuit of your device.
How to identify the correct charge
If you need a new charger, how can you choose a safe and suitable one? Here are some things you need to refer to:
Whenever possible, use the OEM charger that comes with your device. This is designed specifically for your device and battery, and all parameters (voltage, current, charging logic) are optimally matched, and are the safest to use.
If your original charger is lost, please refer to the label of the battery or device to find a replacement charger, which will find the corresponding voltage, capacity, current, charging terminal type and other information.
Please make sure to purchase from reliable channels, choose reputable brands, or choose chargers that are certified by UL, CE, etc.
Charger alternatives
Never settle for just any charger to charge your battery.
We recommend buying an official charger. You can contact the manufacturer of your device directly, or find their designated authorized dealer to buy a charger that is exactly the same as the original one for your device. This is the safest way.
If you can’t buy an original charger, consider buying a high-quality, fully compatible third-party brand charger. It must support lithium-ion batteries, have the same charger output voltage as the battery charging voltage, and have an output current within the range your battery or device accepts. It must have a reliable safety certification mark and the terminals must match consistently.
Conclusion
Lithium batteries are dangerous goods and require specific and fully compatible chargers. Using the wrong charger is not a trivial matter, but a serious safety hazard that may cause fire and explosion. Protecting yourself and your device often starts with using the right charger. If you still have questions, please contact us directly.
