Voltage drop on batteries when connected to ups/inverter

Question

I have recently installed a solar system and trying to understand the voltages of batteries when they are being charged and when they are providing power to load. Here is what I observed:

I have 2 Lead Acid 12v Deep Cycle 200ah batteries connected in series with a 24 volt solar inverter/charger.

During the charging phase I notice that the voltage of batteries as shown on the lcd display go up as high as 29.1 and then stops.

At night when connected with load and providing about 100 watts 220v the batteries read 25.9 in the beginning and drops to about 24.9 in about 6 hours.

Is it normal for a battery to charge upto 29.1v but then read 26v when it starts to provide power to inverter for dc to ac inverter?

Answer 1

That is a normal range of voltage for lead-acid batteries. The voltage may go as low as 22 volts as the batteries discharge.

The "12 volt" battery in a car can be up to 14.5 volts when charging, about 13 volts after sitting not being charged or used for a while, and down to 11 volts under load.