How long does it take to charge a 72v battery with six cells?
3 Answers
72v six-cell battery charging should follow the manufacturer's recommendation of 8 hours to fully charge the battery. Subsequent charging should be based on remaining power and charging frequency. If charging daily, 6 to 8 hours is sufficient. If waiting until completely drained before charging, it's recommended to charge for 8 to 10 hours. For electric vehicles with daily power consumption around 10%, consider extending charging frequency to once per week. When daily power consumption is between 20% to 30%, charge every 2-3 days. For daily power consumption of 40% or more, daily charging is recommended, keeping it within 5 to 6 hours.
I usually commute by electric bike, with a 72V six-piece lead-acid battery pack that has been used for two years. The charging time mainly depends on the discharge level. Last time when delivering takeout, I ran the battery down to 20%, and it took a full 8 hours to fully charge with the original 5A charger. It is recommended to charge when the battery is around 30% left; with a 5A charger, 5-6 hours is sufficient, which helps prolong the battery life. If the battery feels hot during charging, disconnect the power immediately. In winter, the charging time needs to be 1 hour longer than in summer. For the first charge of a new bike, remember to charge for a full 8 hours to activate the battery. It's best to charge in a cool and ventilated place under normal circumstances.
Having repaired electric vehicles for ten years, the charging time for a 72V battery pack depends on its capacity and the charger's power. A 20Ah battery with a 3A charger takes 8 hours when fully discharged, while a 32Ah battery requires over 10 hours. The worst habit is leaving it charging overnight for convenience—lead-acid batteries can swell and become unusable if overcharged. Once the charger turns green, unplug it within an hour at most. If the voltage difference between individual cells exceeds 0.5V, it's time for maintenance. Charging in summer is about 15% faster than in winter, and always remember to ventilate the garage by opening windows.
