A lead-acid battery is a rechargeable battery whose electrochemical reaction is based on a chemical reaction between lead (Pb) and sulfuric acid (H₂SO₄). It was one of the earliest types of rechargeable batteries; Lithium-ion batteries are also a rechargeable battery whose electrochemical reaction is based on the movement of lithium ions (Li⁺) between the positive and negative electrodes, and it is one of the most widely used battery types today.

In some cases, lithium-ion batteries can be replaced with lead-acid batteries, but the following factors need to be considered:

1. Device Compatibility

1.1 Voltage matching: Lithium-ion batteries and lead-acid batteries have different nominal voltages. For example, a common lithium-ion battery voltage is 3.7V, while lead-acid batteries are typically 6V or 12V. If the device is designed to use a lithium-ion battery, replacing it directly with a lead-acid battery may result in a voltage mismatch that can affect device performance.

1.2 Size and weight: Lead-acid batteries are typically heavier and bulkier than lithium-ion batteries. If the device has weight and size restrictions, such as a portable device or an electric vehicle, lead-acid batteries may not be suitable.

2. Performance differences

2.1 Energy density: Lithium-ion batteries have a much higher energy density than lead-acid batteries, which means they can store more energy in less volume and weight. If the device has high requirements for energy density, such as electric vehicles or portable devices, lead-acid batteries may not be sufficient.

2.2 Cycle life: Lithium-ion batteries typically have a much longer cycle life than lead-acid batteries. 

2.3 Charging speed: Lithium-ion batteries charge faster, usually fully charged in 2-5 hours, while lead-acid batteries can take 8-10 hours.

（Figure illustrates the characteristics of lead acid and Li-ion in the field of automobiles. Both chemistries perform similarly in cold cranking. Lead acid is slightly better in W/kg, but Li-ion delivers large improvements in cycle life, better specific energy in Wh/kg and good dynamic charge acceptance. Where Li-ion falls short is high cost per kWh, complex recycling and less stellar safety record than lead acid.)

3. Application Scenarios

3.1 Suitable scenarios for lead-acid batteries:

If cost is a major consideration and the device does not require much battery performance, a lead-acid battery may be an affordable option. In some scenarios where weight and size are not high (such as UPS backup power), lead-acid batteries can meet the demand.

3.2 Suitable for lithium-ion battery scenarios:

Lithium-ion batteries are a better choice for applications that require high energy density, fast charging, and long life (e.g., electric vehicles, portable devices, solar energy storage systems). Or in extreme environments, lithium-ion batteries generally outperform lead-acid batteries in both high and low temperature environments.

4. Safety and environmental impact

4.1 Safety: Lithium-ion batteries generally have better safety mechanisms (such as battery management systems), while lead-acid batteries contain lead and sulfuric acid, which are potentially harmful to the environment and human health.

ACEY-BP24-300A500A battery management system test equipment can detect the function of the lithium battery protection board and various performance indicators. It is especially suitable for factory inspections for mass production. It is developed using the principle of capacitor simulation battery charging and discharging, and has multiple functions. Simple operation, fast detection speed, etc.If necessary, please contact us.

4.2 Environmental friendliness: The recycling and disposal of lead-acid batteries require special attention to avoid heavy metal pollution.

5. Cost and budget

5.1 Initial cost: Lead-acid batteries typically have a lower initial cost than lithium-ion batteries, but lithium-ion batteries last longer and may be more cost-effective in the long run.

5.2 Maintenance costs: Lead-acid batteries require regular maintenance (e.g., water addition, cleaning), while lithium-ion batteries require little maintenance.

In conclusion,if the device does not require the weight, size, energy density, and cycle life of the battery, and the budget is limited, consider replacing the lithium-ion battery with a lead-acid battery. But in applications where high performance, portability, or long life are required, lithium-ion batteries are often the better choice.