4 New Lead Acid Battery Capacity Testing Methods

News 2023年2月8日 80

Lead acid battery is a kind of storage battery that is possible converts electrical energy into chemical energy as well as chemical energy into electrical energy.  Lead acid batteries are widely used in telecommunication, power system, radio and television system, railways, solar, UPS, electric vehicles, forklifts, emergency lights, security, alarm, gardening tool, baby carrier, etc.

Lead acid battery for electric vehicle

The battery is composed of 3 or 6 single-cell batteries in series. The voltage of each single-cell battery is 2V, and the battery is connected in series into 6V or 12V for automobiles.  The lead battery is mainly composed of the container, positive and negative plate, gelled electrolyte, etc.  Its composition is shown in image 1.

lead acid battery gel 2v 12v
lead acid battery parts
  1. The plate is the core part of the battery. During the charging and discharging process, the mutual conversion of electric energy and chemical energy depends on the chemical reaction between the active substance on the plate and sulfuric acid in the electrolyte.  The battery plate consists of a positive plate and a negative plate, which is composed of the grid and active substance.  The active substance was filled on the grid made of lead-antimony alloy. The active substance on the positive plate was brown lead dioxide (PbO2), and the active substance on the negative plate was bluish-gray spongy lead (Pb).  
  2. Separator, in order to avoid the positive and negative plate contact with each other, and lead to short circuit. It separates the positive and negative plates with an insulation partition.  The separator is porous to facilitate free penetration of the electrolyte and reduce the internal resistance of the battery.  
  3. Electrolyte, electrolyte, and the active substance on the plate electrochemical reaction, electrical energy, and chemical energy conversion.  It is prepared with a high concentration of 1.84g/cm3 chemical pure sulfuric acid and distilled water, the standard density is 1.28±0.01g/ g/cm3 (25℃), and the appropriate selection is made according to the local minimum temperature
  4. Container, battery container for holding electrolytes and plates.  It must be resistant to acid, cold, and vibration, and have sufficient mechanical strength. It is generally made of rubber or plastic.  
  5. Connector, the role of the connection bar is to connect the single battery in series.
  6. Pole pile, pole pile has conical and L shapes and other forms, for easy identification, above or next to the positive pile marked with “+” (or P), above or next to the negative pile marked with “-” (or N) mark, or painted red paint on the positive pole.  

Lead acid battery capacity test methods

We know the composition and use of lead-acid batteries.  The capacity of a lead-acid battery is an important index to determine its quality of the lead-acid battery. How to test the capacity of a lead acid battery?

There are two ways to detect electrolyte levels.  

Liquid level height indicator line method

Glass tube measurement method.  Liquid level indicator line method. For batteries with transparent engineering plastic shells, the liquid level of the electrolyte can be checked by observing the liquid level indicator line.

2v1000ah gel lead acid battery
lead acid battery 2v1000ah gel

In the glass tube measurement method, insert a hollow glass tube into the upper plane of the plate inside the battery electrolyte, press the upper end of the glass tube tightly with your finger to seal the tube mouth, lift the glass tube, and the height of the electrolyte absorbed in the glass tube is the height of the liquid level, the standard value should be 10 ~ 15mm.


Battery Voltage Detection  

Learn how to use battery high-power discharge meter to measure electric storage   

Turn off the ignition switch, connect the red clip (needle) of the high-power discharge meter with the positive electrode of the battery, and connect the black clip with the negative electrode of the battery, as shown in the figure;  Press the switch of the high-power discharge meter and hold it for 5 ~ 10s before releasing it. After the pointer on the tester is stationary, read out the reading, as shown in Figure 4. This reading is the terminal voltage of the battery:  

  • Voltage is 11.5 V or higher indicating that the battery is good.  
  • Voltage from 9.6 V to 11.5 V, the battery is good.  
  • Voltage < 9.6 V, the battery to charge or faulty.  
  • Voltage drops rapidly, low value, and damage to the battery.  

Use a multimeter to test batteries in DC voltage mode  

The multimeter has two pens, the colors are respectively red and black.  Insert the red marker in the V /Ω hole, and insert the black marker in the VCOM slot.  Adjust the gear of the multimeter to DC voltage, 20V position;  Press the switch button to open the multimeter, the display is 0.000 and other numbers (according to the precision is different, the decimal number is different);  When the two pens of a multimeter touch the two electrodes of the battery, the multimeter displays the value.  The value is the voltage of the battery;  If the displayed value is negative, you can switch the two pens of the multimeter.  Finally, attention should be paid not to short-circuit the two electrodes of the battery, otherwise, the battery may burst.  

Test the battery power in terms of vehicle type  

Method:  Battery power detection is about to start the car engine, and open the hood, the multimeter range to DC voltage, respectively connected to the car battery between the positive and negative poles, open the car headlights, carefully observe the value of the multimeter change, if the voltage data on the multimeter regularly from 12.6 to 12.5 to 12.4 to 12.3 down.  If the voltage data shows a jump decrease, it indicates that the battery is not working well. Replace the battery in time.  


    This article shares four methods of lead acid battery capacity test.

    • Detection of electrolyte level height.
    • Detection of battery terminal voltage. 
    • Test the battery with the DC voltage file of the multimeter. 
    • On the vehicle type of battery power detection.  It can help the readers.