2. Check whether the outer package is damaged or has been disassembled.
3. Check the appearance of the battery itself, and observe whether there are scratches and corrosion at the positions of the positive and negative terminals.
4. Check whether there is an anti-counterfeiting label on the battery shell, whether the production date is long, whether the relevant information signs of the manufacturer are complete, and whether the handwriting is clear and complete. If the outer packaging of the battery is more than 1 min, it is considered that the battery is old and there may be quality problems.
5. Install the battery that has just been fully charged on the electric vehicle, start the power supply of the electric vehicle, suddenly accelerate the electric vehicle while driving, observe the change of the ammeter pointer, and judge that the ammeter pointer drops less than half a grid when accelerating riding, indicating that the battery is brand-new or has good performance.
Extended data
For battery packs composed of many single cells, such as fixed batteries, after running for a certain date, they should be charged regularly and evenly. This is because when charging under the same conditions, the active materials in different parts of the electrode plate have different charging degrees, which leads to uneven reaction of the active materials.
In addition, considering the differences in some charging and discharging characteristics between single cells, some single cells will be under-charged. Therefore, after normal charging, continue to charge 1 ~ 3h at a current rate of about 20h. This kind of charging is also called overcharge. When batteries are usually used under the same conditions, it is beneficial to carry out balanced charging regularly in battery maintenance.
Different users have different regulations on the interval of balanced charging, and some stipulate that it should be carried out once every three months or half a year. According to the progress of battery design and manufacturing technology, there is little difference in battery characteristics, so the interval of balanced charging is often extended.
Reference source; Baidu encyclopedia-electric vehicle battery