Lithium batteries can not be overcharged and discharged, although lithium iron phosphate batteries are a high security battery, but overcharging will still be a risk.
No matter what kind of battery, overcharging will cause irreversible effects that are not repairable.
Safety hazards: overcharging will cause the battery to heat up abnormally, but also lead to increased pressure inside the lithium iron phosphate battery, resulting in expansion and bulging of the battery and other phenomena, which may have the effect of fire and explosion over time.
Internal changes: during normal charging, the positive electrode lithium ions will be embedded in the negative electrode carbon, when the temperature is too high, the lithium ions can not be embedded in the carbon, but only on the surface of the negative electrode to gain electrons, resulting in lithium monomers on the surface of the negative electrode, which is a kind of irreversible damage to the battery.
Shortened Battery Lifespan: The lifespan of the battery may be greatly reduced due to permanent damage to the battery.
Altered performance: Prolonged overcharging will reduce the internal voltage of the battery, which will reduce the capacity of the battery, shorten the battery’s range, and affect the performance of the battery. For example, a fully charged battery that could be used for 10 hours can now only be used for 7 hours or even less.
Disconnect the power supply immediately after the discovery, if you find the battery is too hot, first stand still and wait for its temperature to decrease, put it in a ventilated place, but can not use water to cool it.
Discharge the battery with a current lower than 0.1C, e.g. 20A for a 200Ah battery, until the voltage returns to the normal voltage range.
If the battery is equipped with a safety valve, open it immediately to release excess pressure from the battery.
Do not overcharge the battery again to avoid continued damage to the battery, charging the battery to 90% is sufficient.
If only accidentally overcharged for a short period of time, and the appearance of the battery as well as the performance has not changed too much can be used, if there has been a hot, swollen and other abnormal appearance of the changes, please stop using it immediately, as soon as possible to contact a professional to deal with it.
Under normal circumstances, the battery charging system will have a specialized protection mechanism, the power will be automatically cut off when full, to avoid overcharging conditions, but there are times when these protection mechanisms will fail. Charger failure, battery aging, charging time is too long, charging voltage and current mismatch, etc., all of these situations will cause overcharging of the battery.
Use the original charger:The original charger can ensure that the charging current and voltage match the battery to avoid damage to the battery.
Regularly check the battery and charger: Regularly check the status of the charger and battery to ensure normal operation, and repair or replace them when abnormalities are found.
Use a Battery Management System (BMS): A BMS is a common type of battery management system that keeps a data log of your battery to help you detect risks such as overcharging in time.
Good charging habits: Know your battery capacity and charging voltage, plan the correct battery charging time, as well as determine the charging current and appropriate temperature according to the manufacturer’s recommendations.
