The development of battery technology is a core issue in the electric car industry such as the electric sightseeing car. Therefore, the series balance of the battery pack is a difficult problem. The battery pack of the same batch may not be in the same state. There are many reasons for this situation, such as the production is not strictly controlled or the use of raw materials.
First of all, the battery of the electric sightseeing car should be normally charged, and then discharged with a 2-hour rate current (discharge current = rated capacity of the battery ÷ 2). The flowing voltage of the battery should be tested during discharging, some of the lagging capacity should be filtered out. It should be continuously charged for more than 10 hours if there is an emergence of the current solution after adding 1.0 sparse acid. The temperature should not be too high during charging, and it should be placed for 0.5 to 4 hours and discharged at the rate of 2 hours again after charging. If the test voltage still does not reach the single-cell voltage of 1.6V, the above operation method should be repeated until it meets the standard.
If the battery capacity is still around 0V low voltage after repeated charging or discharging, the battery may have a short circuit or there are shedding active materials, or severe irreversible sulfation, etc. It should be scrapped because it will not be repaired.