Special charger
Lithium batteries need a special charger, or a self-made charger with cc-cv automatic switching. Remember, the battery cell voltage should not exceed 4.2v Simply put, the maximum charging voltage of four batteries connected in series should not exceed 16.8v (the error should not exceed 5%). Test your charger. If this voltage is exceeded, the battery will be damaged, even if it does not explode, it will seriously affect its life.
Question answer
Isn't lithium iron phosphate battery overcharge-resistant? Why do you need a protective plate? The protective plate is still recommended, and every battery is required. Its function is to prevent overcharge and overdischarge, and the battery will be automatically cut off if the voltage is too high or too low.