Fully diacharge the battery，yes or no？
Jul 30, 2024
| Li-Iron Phosphate (Li-FePO4) batteries are lithium-ion batteries, and when it comes to a series of scenarios such as RVs, off-grid solar systems, and home energy reserves, Li-FePO4 batteries are always discussed. Lithium iron phosphate battery performance is powerful, high energy density, large available capacity, long service life, is a cost-effective type of battery, the scope of application is becoming more and more extensive, but also belongs to the green environmental protection type of battery. There are often questions about the BMS overdischarge protection of batteries, because a battery that was working normally suddenly triggers the BMS protection and does not function properly. When encountering such a situation, most people will think that the battery has a fault, but confirmed by the voltage, most of them are due to over-discharge over the threshold set by the BMS, triggering the BMS protection, in this case, it is often necessary to use the charger that can be activated by 0V, with lithium iron phosphate mode, to activate the battery and restore its use. For example, the SANFOU 14.6V20A charger is equipped with this activation function, which meets the recommended charging rate of 0.2C for SANFOU 12.8V 100Ah batteries. Battery cycle times and charge cycles Battery cycle time refers to the number of complete cycles of the battery from charging to discharging and back to charging.SANFOU Li-FePO4 battery cycle time can reach 4000~5000, much higher than the lead-acid battery's 500 cycles. Charging cycle The charging cycle refers to the process from fully charged to fully depleted, and then from a completely dead state to fully charged. This process is also known as the number of times a battery completes a cycle. In addition, if a battery is used up to 40% from a fully charged state, then charged to a full charge, then used up to 40%, and then continued to be charged to a full charge, then the battery is also considered to have completed one cycle. Battery life is closely related to the number of battery cycles, and as the number of battery cycles increases, the battery capacity decreases. Fully discharged Theoretically, LiFePO4 battery can be fully discharged, the depth of discharge (DOD) is 100%, but in order to maintain the performance of the battery as well as to extend the life of the battery, we usually recommend not to fully discharge, try to maintain the discharge of 80% after charging, in order to improve the performance and life of the battery. Full discharge may cause irreversible damage to the LiFePO4 battery, affecting its service life, and it will cause BMS protection. Properly maintained SANFOU LiFePO4 batteries have a service life of up to 10 years and 4000+ cycles, but long-term overcharging and over-discharging can lead to irreversible damage to the battery, reducing its performance and service life. Deep charging and shallow charging Deep charging and shallow charging relate to the depth of discharge during battery use. Deep charging: The depth of discharge of the battery is deep, that is, charging after a significant discharge, when the discharge is equal to or more than 80% and the remaining charge is 20% or less, then charging the battery belongs to deep charging. Deep charging tends to put more stress on the battery, which can lead to faster battery aging and reduced battery life. Shallow charging, on the other hand, occurs when the battery is only partially discharged (when the remaining charge is equal to or greater than 50%). This approach puts less stress on the battery and helps extend the overall battery life. Due to the varying depths of discharge, the number of charges involved can become unpredictable. Here we have to distinguish between the number of charges and the number of cycles; the number of charges is not the number of battery cycles. The number of charging times can be up to tens of thousands of times depending on the depth of charge and discharge, but the number of cycles of SANFOU lithium iron phosphate batteries is maintained at 4,000 to 5,000 cycles as the battery maintenance floats. Depth of charge cycle times may be reduced, the battery life is shortened; shallow charging is more conducive to extending battery life, SANFOU LiFePO4 deep cycle battery, deep discharge, cycle up to 4000 +, each discharge 50%, can be charged about 8000 times. This also reflects the importance of battery monitoring and maintenance, always pay attention to the remaining capacity of the battery, timely charging, long-term unused batteries should also maintain a certain amount of power to maintain battery performance. Maintenance 1. Avoid overcharging and overdischarging Overcharging and overdischarging will cause irreversible damage to the battery. 2. Avoid deep discharge and recharge Deep discharging and recharging will reduce the service life. Partial discharge (when the remaining battery power is higher than 20%) and then charging, can better extend the battery lifespan. 3. Avoid high humidity in the storage and use environment of the battery. Storing or using lithium-ion batteries in a high humidity environment will damage the battery life and performance. 4. Avoid operating environment temperature exceeding the battery limit threshold. Use the battery at the temperature indicated in the instruction manual. 5. High and low temperatures can affect the internal chemistry of the battery. 5. 5. Use lithium iron phosphate mode charger, or use lithium iron phosphate special charger Using a charger designed for lithium-ion batteries can help customize charging and limit damage to the battery. The charger supplied with the battery is the best choice. Note the optimal charging voltage and current for LiFePO4 batteries, e.g., SANFOU 12.8V 100Ah LiFePO4 battery recommended charging voltage is 14.6V, charging current is 20A (0.2C charging rate, 5 hours full charge). Conclusion Full discharge is not recommended and will affect battery performance and health. For optimal performance and longevity, please follow the guidelines in the manual when using the battery. |
