What causes an electric vehicle's lithium-ion battery pack to fail to charge? Lithium-ion batteries are typically charged using constant current charging, constant voltage charging, or pulse charging, with different methods used at different stages. Electric vehicle lithium-ion battery packs have a self-discharge characteristic; if left unused for extended periods without charging, self-discharge will deplete the battery, resulting in low voltage and preventing it from charging.
What could be causing a lithium-ion battery pack in an electric vehicle to fail to charge?
The following are some reasons why an electric vehicle's lithium-ion battery pack may fail to charge: the charger may be connected incorrectly or the charger may be faulty; the protection board may not reset or the protection board may be faulty; or there may be an external open circuit between the lithium-ion battery pack and the electrical appliance.
When troubleshooting the above malfunctions, check the following in order: whether the charger is connected in reverse; whether the positive and negative terminals of the lithium-ion battery pack are connected in reverse; restart the appliance to remove the protection board's protection; measure whether the MOSFET on the protection board has a drive voltage; and check whether the wiring connections are loose or disconnected.
The main reason why electric vehicle lithium-ion battery packs cannot be charged
1. Check if the circuit connections are secure and whether chargers are being used interchangeably.
When charging the lithium-ion battery pack of an electric vehicle, check that the socket and charging cable are working properly to prevent charging failure due to a malfunctioning or loose socket. Use the charger that is compatible with your electric vehicle to avoid using chargers from other vehicle models or types, which may result in ineffective charging.
2. The battery is severely bulging, causing the electric vehicle to fail to charge.
First, measure the bulging battery to check if it can still be used. How to repair it? Open the battery compartment and open the sealed filler cap on the battery (do not lose the rubber cap on the filler cap). Observe if there is still liquid. Use a syringe to draw 5 to 10 ml of distilled water and add it to the filler hole, adding gradually until the liquid just covers the electrode plates. It is better if there is a water level indicator on the outside.
3. The lithium-ion battery pack has been stored for too long, resulting in a low voltage and preventing the charger from charging it.
Lithium-ion battery packs in electric vehicles can suffer significant damage if left unused for extended periods. Common issues include the battery entering a dormant state and becoming unusable, or, more seriously, the battery fluid drying out. The simplest solution for these situations is to try charging with a lower-powered charger first, and then switch to the original charger once the voltage has increased.
4. Problems with the battery charging IC or BMS system.
Problems with the lithium-ion battery management system can occur due to factors such as cell imbalance, leading to misjudgments by the management IC and its inability to detect voltage or current.
What's the best way to charge a lithium-ion battery pack for an electric vehicle?
● If a low battery warning appears while driving an electric vehicle, it should be charged as soon as possible. Lithium-ion battery packs begin sulfidation after discharge, with noticeable sulfidation appearing after about 12 hours. Timely charging can remove minor sulfidation; otherwise, these sulfide crystals will accumulate and gradually form larger crystals.
● Always use a compatible lithium-ion battery charger. First, insert the charger's output plug into the corresponding battery charging socket, then insert the charger plug into a mains power outlet. Observe the indicator light to determine if the battery is charging. If the charger is lost or damaged, please contact the corresponding dealer to purchase a replacement. Do not use lead-acid chargers or other types of chargers.
● If you are away from home or leave the vehicle for an extended period, the lithium-ion battery pack of the electric vehicle may experience self-discharge, causing "power loss". A depleted battery will seriously affect the battery's lifespan. It is recommended to charge the battery once a month.
In summary, the above explains the reasons why electric vehicle lithium-ion battery packs may not charge and the correct charging methods. Through this sharing, you should have a better understanding of the correct charging methods and process for electric vehicle lithium-ion batteries. Correctly controlling the charging time of lithium-ion battery packs will extend the life of electric vehicle batteries.
