2. When in use, if the voltage reduces by 1.75V, for example, from 6V to 5.25V, from 12V to 10.5V, or the electrolyte density reduces to 1.170, the cell should be recharged.
When the cell is being recharged normally, what is the proper temperature of the electrolyte?
The temperature should not be over 45. When the temperature is approaching 45, you should stop recharging the cell or reduce the charging current by half. When the temperature is lower than 35, recharging process can continue.

3. How to judge that the cell is fully charged and stops charging?
When a lot of the bubbles are generated during charging, the single voltage is between 2.4V to 2.8V, the density of the electrolyte increases to 1.280+9.995(25), and the density and the voltage keeps stable for 2-3 hours, the cell is fully charged.

4.When the storage cell is being charging, if the voltage has reached between 24V-2.8V, and the electrolyte density cannot reach 1.280+0.005(25), what measures should be taken?
When the density is low, adjust with the electrolyte whose density is 1.4. When the density is high, adjust with pure water until the accurate electrolyte proportion (1.26-1.28) is reached.

5. When should the electrolyte be refilled?
When in daily use, you should frequently check the height of the electrolyte to ensure it is over the minimum line. If there is no minimum line, the height of the electrolyte should be 10-15mm higher than the protection board.

6.What measures should be taken in winter and summer when the electrolyte is in short?
Refill with the vitriol electrolyte whose density is 1.05 in winter, refill with water in summer.

7.How to deal with the storage cells which are discharged?
Discharged cells should be recharged in time to prevent from the sulfuration of the anode. In cold seasons, they should keep charging often.