a. Control the charging power to avoid overcharging and excessive gas production.

b. Avoid open flames near batteries during the charging process and ensure good ventilation.

c. Ensure a firm connection during charging to prevent sparks from loose connections.

d. Use a constant current and limited voltage charging method to reduce gas evolution.

e. Prevent sparks or even fire and explosion due to short circuits.

f. For maintenance-free sealed batteries, keep the degassing hole unobstructed to prevent the accumulation of internal pressure and potential bulging or explosion.

a. If the density is too high, it can cause plate sulfation and accelerate grid corrosion. If the density is too low, it can affect the discharge capacity.

b. Under normal charging conditions, if the density does not increase significantly or even remain unchanged, there is a possibility of plate sulfation, which may need countermeasures to eliminate sulfation.

c. After the battery is charged, if the density decreases significantly during the resting period, it indicates severe battery self-discharge, which may be caused by impurities in the electrolyte. If the electrolyte shows abnormal color or smell, or even shows turbidity, t indicates impurities have entered the battery.

d. If the electrolyte shows the color of metal ions, there is a possibility of contamination.

Filling new batteries with acid is due to the neutralization reaction between the acid and the oxidized negative plates, which generates a significant amount of heat. During this period, charging should only start once the electrolyte temperature drops to around 40℃, or the battery should be charged with a low current.

During normal charging, if the electrolyte temperature is high or exceeds 45℃, cooling measures should be taken to cool the battery or the charging current should be reduced. If the temperature does not decrease, the possibility of a battery internal short circuit or plate sulfation should be considered.

During normal usage of the battery, if the temperature is too high, there are two possibilities: one is that the surrounding ambient temperature is too high and the heat generated by the battery is not easily dissipated. The other is that the charging voltage or current is too high.

When recharging a normal battery, there should not be a large number of bubbles (gas) generated during the primary charging period, as the current is only serving the electrochemical reaction of the active mass. While at the end of the charging period, along with the completion of the electrochemical reaction, the current charged begins to electrolyze water, and degases hydrogen and oxygen.

If there is only a small amount of gas generated at the end of the charging period when recharging the battery after usage, it may be due to the charging current being too low or the battery not being fully charged. If only one single cell shows no gas generation during battery charging, this may indicate an internal short circuit. On the other hand, if the entire battery produces too much gas and too early, this indicates the possibility of plate sulfation, which should be treated with repeated discharge and charge processes. If the battery produces gas in the resting period or discharge process, it may be caused by impurities in the electrolyte.

After charging, the voltage of each single cell should be around 2.1 V (may be affected by electrolyte density). If the voltage is low during primary usage, check if the battery is fully charged or if the electrolyte density is too high or too low.

If the battery shows a comparatively higher voltage during charging, along with numerous bubbles and a fast voltage drop during discharge, this may indicate plate sulfation. Fully discharge the battery with low current and then charge the battery with low current (0.1C20), repeat the discharge and charge steps several times. The effectiveness of this method may be affected by the degree of sulfation.

a. Sulfation (over-charge, repeated charge, hydrotherapy for desulfurization)

b. Pollution of electrolyte (after multiple flushing with distilled water, change the electrolyte)

c. Partial short circuit in the batteries.

d.  Grid corrosion, plate breakage, or active mass shedding, which can occur at the end of the battery's service life.