How to judge the quality of car batteries?

1. Look at the old and new battery: In fact, this is a good judgment. Generally, you can judge whether there are scratches or scratches by looking at the appearance, and then see whether there is rust on the positive and negative metal parts of the battery. 2. Use a professional voltage measurement tool to determine whether the battery has an internal short circuit (bad battery): After riding for a while or after charging the car and letting it stand for several hours, measure the voltage at the charging plug and it is 48 volts. Or a higher point is a normal battery (no distinction between old and new). If it can only reach 46 volts or below, it means that there is a short circuit in one battery (there are four groups of batteries in a 48 volt car, and each group consists of 6 2 volt batteries connected in series to become 12 volts), indicating that the 10 volt group is a bad battery. 3. Judging the end-of-life battery: 1) After the battery is fully charged, if the bicycle is suddenly accelerated and the battery gauge needle drops less than half a mark (a small mark), it is a new battery. 2) After the battery is fully charged, if you suddenly accelerate the ride and the battery gauge needle drops one mark, it is a half-new and old battery. 3) Just after fully charged, if you suddenly accelerate the ride and the battery gauge needle drops 2-3 bars, it is an old battery that is about to be scrapped (the battery will run out of self-discharge if it is fully charged for half a month without riding). 4) After being fully charged, if you suddenly accelerate and ride more than four bars, the battery will be scrapped. (Not fully charged for a week. Statement: Some pictures and contents of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What should I pay attention to for lithium batteries for electric vehicles that run far?