A lead acid battery is considered fully charged when its voltage level reaches 12.7V for a 12V battery. However, this voltage level may vary depending on the battery’s manufacturer, type, and temperature. What are the voltage indicators for different charge levels in a lead acid battery?
The 24V lead-acid battery state of charge voltage ranges from 25.46V (100% capacity) to 22.72V (0% capacity). 48V Lead-Acid Battery Voltage Chart (4th Chart). The 48V lead-acid battery state of charge voltage ranges from 50.92 (100% capacity) to 45.44V (0% capacity). Lead acid battery is comprised of lead oxide (PbO2) cathode and lead (Pb) anode.
For example: In a 12V 45Ah Sealed Lead Acid Battery, the capacity is 45 Ah. So, the charging current should be no more than 11.25 Amps (to prevent thermal runaway and battery expiration). Importantly, if you have other equipment connected to the battery during chargning, it also needs to be powered, so you need to add that to your calculations.
The highest voltage 48V lead battery can achieve is 50.92V at 100% charge. The lowest voltage for a 48V lead battery is 45.44V at 0% charge; this is more than a 5V difference between a full and empty lead-acid battery. With these 4 voltage charts, you should now have full insight into the lead-acid battery state of charge at different voltages.
Temperature affects lead acid battery voltage levels. The voltage level of a lead acid battery increases as the temperature decreases and vice versa. Therefore, you need to consider the temperature when measuring the voltage level of a lead acid battery. At what voltage level is a lead acid battery considered fully charged?
Lead acid batteries must always be stored in a charged state. A topping charge should be applied every six months to prevent the voltage from dropping below 2.10V/ cell. With AGM, these requirements can be somewhat relaxed.