Lead-acid battery is a kind of electrode mainly made of lead and its oxides, and the electrolyte is concentrated sulfuric acid and water. Lead-acid battery in the discharge state, the positive electrode is mainly composed of lead dioxide, the negative electrode is mainly composed of lead, in the charging state of the positive and negative electrodes are mainly composed of lead sulfate.

Lead-acid battery charging

1. The chemical reaction equation of lead-acid battery in charging

PbSO4+2H2SO4+PbSO4→PbO2+Pb+2H2O4(under energized condition) i.e. anode+electrolyte+cathode→lead sulfate+water+lead.

2. Lead-acid battery chemical changes in charging

Charging occurs in the anode plate, lead sulfate on the cathode plate will be decomposed and reduced to sulfuric acid, lead and lead dioxide in the charging process, the concentration of electrolyte inside the battery will rise, this change means that the active substance inside the battery has been converted to a state that can be supplied with electricity, and the charging state ends when the lead sulfate at the two poles is converted to the original active substance. Note that when charging lead-acid batteries should be in an area with good ventilation conditions, and sparks or water are prohibited.

Lead-acid battery discharge

1. Lead-acid battery discharge chemical reaction equation

PbO2+2H2SO4+Pb→PbSO4+2H2O+PbSO4(discharge reaction) i.e. anode+electrolyte+cathode→lead dioxide+sulfuric acid+sponge lead.

2. Lead-acid battery changes in discharge

Lead-acid batteries in the discharge state, dilute sulfuric acid will react with the active substances on the anode and cathode to produce new compounds of lead sulfate, when the active substances on the positive and negative plates become the same lead sulfate, the battery voltage drops to the point where it can no longer discharge.

how to charge 12v lead acid battery?

1.Check lead acid battery

1.1 Check the appearance of the lead acid battery for any dents or protrusions, which may affect the integrity of the casing and the charging efficiency.

1.2 Check the appearance of the lead acid battery whether there are cracks or crack phenomenon, there are cracks or cracks will occur in the accident of leakage.

1.3 Check the appearance of the lead-acid battery for any foreign matter or pollution, any foreign matter or pollution will affect the performance of the battery and reduce the efficiency of the battery.

1.4 Check whether the lead-acid battery harness connection terminals are connected reliably to improve charging efficiency.

2. Determine the charging method

The charging method of lead-acid battery needs to choose different charging equipment according to different situations, usually the charging method of lead-acid battery has fixed-current charging, fixed-voltage charging, rapid charging (pulse charging) and so on, and it is recommended to use pulse charging, which is described as follows.

2.1 Constant-current charging, in the charging process, the charging current to maintain a constant charging method, known as constant-current charging. Fixed-current charging has great applicability, can arbitrarily select and adjust the charging current, can be a variety of different lead-acid battery charging, but the disadvantage is that the charging time is long, and the need to frequently adjust the charging current to match the different charging state.

2.2 Constant voltage charging, in the charging process, the voltage is always constant method is called constant voltage charging, in constant voltage charging need to pay attention to the charging voltage, if the charging voltage is too high, overcharging phenomenon will occur, resulting in lead-acid batteries plate bending, active material off a lot of the battery’s temperature will rise. If the charging voltage is too low, the phenomenon of not charging will occur. And constant voltage charging needs to connect the lead-acid battery in parallel between the charging power supply, the charging time is longer, which may affect the use.

2.3 Fast charging (pulse charging) Fast charging can overcome the polarization phenomenon produced during the charging process, and can improve the charging efficiency, the main advantage is that the charging time is shorter, and it can increase the capacity of the battery, mainly due to the fact that the pulse fast charging can eliminate the polarization phenomenon of the battery, and the charging of the chemical reaction is sufficient, so that the battery’s capacity is increased, and there is also the obvious de-sulfurization effect, but the pulse charging But the price of pulse charger is higher than ordinary charger.

3. Check the lead-acid battery charger

3.1 Check whether the parameter specification of the charger corresponds to the lead-acid battery, the use of different specification charger will be incompatible with the lead-acid battery, resulting in charging is not possible, replace the charger with the same parameter specification.

3.2 Check whether the appearance of the charger has corrosion and other phenomena, the charger has corrosion phenomenon may also lead to failure to charge.

3.3 Check whether the charger cable has broken circuit, damage phenomenon, there is damage will occur leakage or can not charge the fault.

3.4 Check the charger port, the port has a foreign body can also lead to poor contact or can not charge.

4. Check the safety equipment

Check insulated gloves, goggles, protective clothing for damage to prevent sparks or electrolyte leakage causing injury.

5. Connecting the charger

First identify the positive and negative terminals of the lead-acid battery, which are usually labeled with plus (+) and minus (-) signs. Connect the positive terminal of the rechargeable battery to the positive terminal of the battery and the negative terminal of the charger to the negative terminal of the battery. During operation, be careful to connect the positive terminal first and then the negative terminal, and avoid having metal objects on your body or touching other metal objects.

6. Turn on the power

After connecting all the devices correctly, you can turn on the power to charge the lead-acid battery. If you turn on the power to charge before the connection is completed, electric shock may occur.

7. Check the battery charging status

When the battery is being charged, you can use a multimeter to check the voltage status of the battery. The voltage of the battery will rise with the charging time, and when it is fully charged, the voltage of the battery can reach about the rated voltage. If any abnormality is found, please disconnect the power immediately.

8. Disconnect and clean

After the lead-acid battery is fully charged, disconnect the negative terminal and then the positive terminal. Then check whether the battery can work normally, and finally use a clean cloth or towel to wipe the battery.

Summarize:

The charging and discharging of lead-acid batteries need daily maintenance, pay attention to the charger specifications, charging environment, charging voltage when charging, and avoid deep discharge when discharging, so that the lead-acid batteries can be used for a longer period of time.