Can a lead-acid charger be used to charge lithium batteries? We have already explained this issue in previous videos, but many fans still don’t understand. This time, we will explain the correct charging method for lithium batteries in one go. We want to remind everyone that when connecting batteries, we must first connect the battery and then connect to 220V. When the battery is fully charged, we must first unplug the battery before unplugging the 220V. For example, a 48V lithium battery on the market is mostly a 13-series ternary battery, with a charging voltage of 54.6V. A 60V lithium battery is usually a 17-series ternary battery, with a voltage of around 71.4V. A 72V lithium battery is usually a 20-series ternary battery, with a charging voltage of 84V. However, lead-acid batteries have a charging voltage higher than the highest charging voltage of lithium batteries. Therefore, if we charge lithium batteries without saturation, it will cause overcharging and safety hazards. Different types and series of lithium batteries have different charging voltages, so when selecting a charger, we should match it according to the battery type and series. If we store lithium batteries for a long time, we should ensure that they are stored at half charge. We should not charge lithium batteries below 0 degrees Celsius, as this will cause permanent damage. If possible, we can add a timer charging function to the lithium battery charger. It is also not allowed to charge lithium batteries indoors. If the voltage of the charger is too high or too low, the lithium battery will not be fully charged. For example, the protection board of a ternary lithium battery is designed to protect each cell at 4.25V, while the charger is designed based on a single cell voltage of 4.2V. If the voltage of the charger is too low, the lithium battery will not be fully charged, and if it is too high, the charger will not enter the constant voltage state, and the battery will still not be fully charged.