Precautions for purchasing 18650 lithium batteries.
Dear Sir We like.to ask if you also.make Batteries.for Military Aircrafts.. If yes. Pls.contact me. Regards/18650 The core elements of lithium battery selection
Choosing 18650 batteries is not just about looking at price or capacity. The following core elements must be carefully considered when selecting.
Capacity (mAh): Higher is not necessarily better
Capacity is an important indicator for measuring battery life, usually measured in milliampere hours (mAh). In theory, the larger the capacity, the longer the battery can be used. The common 18650 battery capacities on the market range from 1800mAh to 3500mAh. However, it should be noted that many cheap batteries may falsely label their capacity, with the labeled capacity far exceeding the actual value.
More importantly, high capacity often means lower discharge rates. If your device requires high power output (such as power tools, certain high-intensity flashlights), simply pursuing high capacity while ignoring discharge rate may lead to decreased battery performance, severe heating, and even damage.
Discharge rate (C or maximum continuous discharge current): determines whether it can drive your device
The discharge rate (C-rate) or maximum sustained discharge current is an important indicator of a battery's ability to release energy per unit time. It determines whether the battery can stably supply power to high-power devices. For example, a battery with a nominal maximum continuous discharge current of 20A can stably output a current of 20 amperes for a long time.
For devices such as electronic cigarettes, power tools, drones, and high-power flashlights that require instantaneous or continuous high current discharge, batteries with high discharge rates must be selected. If a battery with insufficient discharge rate is used, it may limit the performance of the device, shorten the battery life, or cause danger due to overheating of the battery. The common power type 18650 battery can provide a continuous discharge current of 10A, 20A, or even 30A or more.
Simply put:
If your device is low-power (such as a regular flashlight or a portable power bank), you can choose a higher capacity battery.
If your device is high power consuming (such as power tools, electronic cigarettes), you must prioritize selecting power type batteries with high discharge rates before considering capacity.
Brand and Quality: The Foundation of Safety and Reliability
Choosing a well-known brand is the most direct way to ensure battery quality and safety. Internationally renowned battery cell manufacturers include Samsung, LG, Panasonic (now partially acquired by Murata), Sony (now acquired by Murata), Wanxiang A123, Molicel, and others. The battery cells produced by these large factories have stable performance, relatively accurate labeling of capacity and discharge rate, and strict safety testing.
Try to avoid purchasing 18650 batteries with unknown sources and exceptionally low prices, as they are likely to be recycled old cells, inferior cells, or falsely labeled products, posing significant safety hazards.
Internal Resistance: A Reference for Battery Health
The internal resistance of a battery is the resistance encountered when current passes through the interior of the battery. The smaller the internal resistance, the better the discharge performance of the battery and the less heat generated. The new high-quality battery has a lower internal resistance, which gradually increases with increasing usage and time. Although it is not convenient for ordinary users to measure internal resistance, understanding the approximate range of internal resistance when purchasing and checking whether the seller has provided relevant data can serve as a reference for judging the age and quality of the battery.
