In this era of rapid technological advancement, Lithium battery Pool pack It has become an indispensable part of our daily lives. From everyday devices like smartphones and laptops to essential electric vehicles for travel, lithium batteries… pond Their presence can be seen everywhere. However, lithium batteries… pond In fact, there are also varying grades—different qualities of… Battery There are significant differences in performance, safety, and service life.

Lithium cell (a single lithium battery) as a lithium battery PACK The fundamental constituent elements of a product currently lack a unified industry standard for clear delineation. A 、 B 、 C Regarding product grades, some companies and industry organizations establish their own classification standards based on their manufacturing processes and market demands. In contrast, remanufactured and scrapped batteries are those that have been used for a period of time, circulated through various channels, and subsequently retired; their origins are often unclear, their performance is uncertain, and they pose significant safety risks. So, As an ordinary person Users and How should consumers make their selection? Next, let’s delve together into the secrets of lithium‑ion battery cell quality.

I. On the Determination and Origin of Cell Grade at Factory Exit

of the lithium battery cell A 、 B 、 C The grading of battery cells is typically determined through an evaluation that considers multiple factors, including performance, quality, appearance, and safety. Below is an excerpt from the criteria used by a well-known battery manufacturer to assess its own cell products:

The table assigns grades based on three performance metrics: discharge capacity, open-circuit voltage ( OCV ), internal resistance ( OCR ). The factory‑grade classification is determined based on the deviations of these three performance indicators.

Of course, the above is just a single example, provided solely for illustrative purposes. Regardless of the grade, in addition to meeting the aforementioned specification requirements, safety is the most fundamental consideration; appearance and dimensions are also important criteria. As… A When evaluating the battery cell, in terms of appearance, should It is exquisite and flawless. Battery PACK The membrane is smooth and tightly sealed, with no wrinkles, bubbles, or damage; the electrode interfaces are flat and polished, showing no signs of oxidation or corrosion, thereby ensuring excellent electrical conductivity and stable connectivity. In terms of dimensions, the product strictly adheres to the design specifications, with extremely tight tolerances for thickness, length, and width. As B Quality battery cell ， Its emergence is primarily attributable to defect rates in the manufacturing process. Even leading lithium‑battery manufacturers struggle to reduce these defect rates to zero, typically at… 2% Around, while the defect rates of second- and third-tier manufacturers may reach 5% - 10% . These, due to minor defects, fail to meet A A battery cell that meets the standards then becomes B Product.

Common defects Battery PACK There may be slight differences in capacity, or minor deviations in length, width, and thickness from the order specifications, but it still fits the vast majority of devices. It is worth noting that, B The battery cell’s performance is absolutely uncompromised; it delivers a stable voltage, providing reliable power to the device. In terms of cycle life, it also… A The battery cells are virtually identical and can withstand repeated charge–discharge cycles.

And C product and below Battery cell, In principle, it is not permitted to leave the factory if, during manufacturing, the performance parameters deviate excessively. Or… It is due to B The battery cells are stored in the warehouse. 8 This situation arises when a product remains unshipped for more than one month. Prolonged storage triggers a series of adverse reactions within the battery cells. Self-discharge continuously depletes the charge, leading to a significant reduction in cell capacity. Meanwhile, the ingress of dust and moisture accelerates cell aging, rendering its performance highly unstable. In terms of appearance, C Battery cells often exhibit swelling, with the battery casing bulging—this is a sign of internal pressure imbalance. During charging, leakage may also occur, as the electrolyte inside seeps out, which not only corrodes the battery itself but can also damage the device in use. Short circuits are even more… C A major safety hazard of battery cells is that, once triggered, a sudden surge of high current can lead to overheating, ignition, and even explosions.

Two , Disassembled item and scrap materials

First of all, let me say... Refurbished item Lithium battery / Battery cell 。

This type of Battery Mainly derived from Two approaches: one is for power lithium batteries that have reached the end of their service life; the other is… Batteries removed from the underbody of new-energy vehicles that have been scrapped or flooded, as well as battery cells salvaged from various used electronic devices.

On the cascade utilization of retired power batteries, national standard GB/T 34015-2017 (Recycling and Utilization of Automotive Power Batteries—Residual Energy Testing) has established corresponding provisions. Among them, the standard’s section … 3 Section: Requirements for Cascade Utilization, which specifies the conditions that end-of-life power batteries must meet to qualify for cascade utilization. Paragraph 4 Section: Second‑life product labeling clarifies that second‑life enterprises must affix compliant labels to conspicuous locations on their products. These standards provide clear technical specifications and operational guidance for the second‑life utilization of lithium batteries. However, Unscrupulous merchants, in pursuit of exorbitant profits, Disregarding the standard requirements, Often will take Non-compliant retired batteries Disassemble After solving, Selling under the guise of a brand-new battery cell. 。

As for the second method, the refurbished units offer even less assurance. Its source more Complex; the quality of disassembled battery cells is highly inconsistent. , these batteries After undergoing secondary capacity grading and other simple processing steps, it is then released onto the market. ， This poses a significant safety risk to consumers.

When identifying refurbished battery cells, start by examining the cell’s connection points. Genuine, brand‑new cells have smooth, neatly arranged connections with clear positive and negative markings; in contrast, refurbished cells may show soldering marks, cracks, or deformation, and their markings may be faint or absent altogether. Inspecting the packaging and labeling is equally critical: authentic products feature a complete set of information on the box—product name, model number, manufacturing date, after‑sales contact details, and more—while the packaging remains intact. Refurbished cells, by contrast, often come in flimsy packaging, with unclear or altered labels, or even no packaging at all. Visually, refurbished cells are likely to bear scratches, dents, or stains, and their dimensions may be irregular, deviating from the standard specifications of genuine cells. Additionally, specialized equipment can be used to measure key parameters such as capacity, internal resistance, and voltage. Because refurbished cells have already been used, their capacity will have declined and their internal resistance will have increased, resulting in performance metrics that differ markedly from those of new cells.

Then let’s talk about… Scrapped battery cells 。

Such battery cells often suffer from severe defects during manufacturing, or sustain significant damage during use or storage, resulting in a complete loss of performance and a total compromise of safety. With regard to regulations on the disposal of lithium batteries, the “Guidance on Lithium Battery Health Assessment,” jointly issued by the Ministry of Industry and Information Technology, the State Administration for Market Regulation, and the Fire and Rescue Bureau, stipulates the following: 5 Scenarios of scrapping:

1 1. Physical damage: A lithium battery must be scrapped if its casing is cracked or leaking, the cell‑protection circuit is exposed, wiring or the circuit board is visible, or if the battery exhibits severe deformation, signs of shell ablation, or damage to the charge/discharge connector that cannot be repaired.

2 1. Exceeding the service life: If a lithium battery has surpassed its specified service life, prolonged use may lead to the formation of dendrites inside, which can puncture the battery separator and cause a short circuit, posing a risk of fire or explosion. Such batteries should be retired.

3 , Incomplete battery label information: From 2024  Year 11  month 1  Batteries manufactured on or after this date must have 3C The battery must bear a certification mark, and its label must clearly display specifications such as voltage and rated capacity; otherwise, it will be deemed a substandard battery, posing safety risks and requiring disposal.

4 , the battery internal resistance is greater than 0.5 Ohm: Excessive internal resistance in the battery can generate significant heat during use or charging, potentially leading to a fire. If the battery’s internal resistance exceeds ohms, it must be discarded.

5 , the battery degradation exceeds 50% : Lithium batteries experience capacity fade during use; if the degree of fade exceeds 50% , such as originally being able to travel when fully charged 100  An electric vehicle with a range of kilometers now travels only when fully charged. 50  Kilometers indicate that the battery is nearing the end of its service life and should be scrapped.

Must Note that once electricity is detected… pond If there are signs of obsolescence, the item must be immediately taken out of service and properly disposed of. Otherwise, it could easily lead to serious safety incidents. In recent years, the use of obsolete or scrapped equipment has… Lithium Electricity pond Fires and explosions caused by this occur from time to time.

Identification Scrapped battery Time , you can first From the appearance Let’s do the recognition. Scrapped battery cells typically exhibit severe deformation, with the battery casing twisted and cracked, as if they had endured a… “ Disaster ” Bulging and leakage are also extremely common: gas accumulates inside the cell, ruptures the casing, and electrolyte leaks out uncontrollably, corroding everything in its vicinity.

Three , Adopt a multi-pronged approach to accurately identify lithium battery cells.

First of all, the purchasing channel is of paramount importance.

It is recommended to choose reputable, well-known options. of or reputable Lithium Battery suppliers. These channels typically maintain rigorous procurement‑approval processes, ensuring the highest possible quality of the battery cells used in their products. Products sold through authorized channels usually come with detailed user manuals, certificates of conformity, warranty cards, and other documentation, providing consumers with comprehensive after‑sales support.

Secondly, View Product Certification mark 。

For example, of the electric bicycle 3C Certification, including the certification standards for lithium batteries. GB 43854-2024 ， For lithium‑ion cells, safety and reliability are tested under a variety of fault conditions. The presence of these certification marks indicates that the product has undergone rigorous scrutiny in terms of both safety and quality.

Again is Professional equipment testing provides more precise data support. A capacity tester can accurately measure a cell’s actual capacity and, by comparing it to the nominal capacity, determine whether it meets specifications. An internal resistance tester measures a cell’s internal resistance; generally, the lower the internal resistance, the better the cell’s performance.

Finally is Price Comparison 。 If a certain model Lithium battery products The price is far below the market average—especially ridiculously low—so you should be cautious; it’s very likely that substandard materials are being used. C They use high‑quality cells, and even recycled or end‑of‑life ones. After all, you get what you pay for: the cost of premium‑grade cells ensures their price won’t be excessively low.

Conclusion

Lithium battery Battery Pack The quality directly affects what we use. Vehicle type or The performance, safety, and lifespan of electronic products. As consumers, make informed choices by evaluating multiple factors—such as official distribution channels, certification marks, professional testing, reasonable pricing, and aesthetic details—to select high‑quality lithium batteries. pond Only then can you enjoy long-lasting battery life and peace of mind, fully embracing the convenience and benefits of technology while staying clear of the potential risks posed by substandard battery cells—and welcoming a worry-free lifestyle.