Can Lithium Batteries and Lead Acid Batteries be Used Together?

Introduction

As we know, the lead-acid battery has excellent quality, good performance, and high charge saturation, which can improve the service life of the battery.

Lithium-ion batteries have higher requirements on chargers and require protection circuits. The lithium batteries usually have high control precision and can perform constant current and constant voltage charging on lithium-ion batteries. Can lithium batteries and lead-acid batteries be used together?

Fig.1

Desirable but not recommended

Different types of lithium batteries and lead-acid batteries are not recommended for use together, because the load characteristics and capabilities of the battery are different, which will lead to abnormal conditions and safety issues. Batteries with completely different performances should not be used in parallel. Even if diodes are added, self-discharge between the batteries can be prevented, but a good parallel discharge effect is not obtained.

Charger

The charger of lead-acid battery is generally set to two-stage or three-stage charging mode, the charge is not matched for lithium and lead-acid battery due to different voltage levels. The lithium battery also has many kinds with different performance and parameters, the protection board parameters may all be different. Therefore, lithium batteries are not like lead-acid batteries, and do not have general-purpose battery chargers.

Generally, lithium batteries are equipped with special chargers when they are shipped out. In order to protect lithium batteries, specific chargers are necessary. When an emergency situation, if you have to charge the battery. The ideal situation is to take the same type of charger, do not fully charge. The lead-acid battery uses lithium battery charger will be undercharged, lithium battery use lead-acid charger will overcharge, so it is better to use the respective charger.

The lead-acid battery and the lithium battery have different capacities and voltages, the charger cannot be used indiscriminately because the charging voltages and currents of the two stages required by the two batteries are not equal. When the lead-acid battery is charged, the charger voltage is high; while the lithium battery technology requires high, so the charger uses constant current and constant voltage charging, lithium battery use lead-acid charger will overcharge and there is a danger of explosion.

Which is better for lead-acid batteries and lithium batteries?

1.Lithium battery is light in weight and large in specific energy, but has high safety and high-cost performance. The same lead-acid battery is heavy in weight, larger in volume and small in energy density, but it has good safety and the price is cheaper.

2.lithium battery is a rechargeable battery, and lead-acid battery is an alkaline battery; lithium battery cycle life of more than 2500 times, lead-acid battery cycle life of 800 times; the energy density of lithium battery is around 150Wh/kg, lead-acid battery is about 40Wh/kg; the charging time of the lithium battery can be full within 4 hours, and the lead-acid battery is generally full around 6 hours;

3.lithium battery charge and discharge electrical energy efficiency is better, lithium-ion battery charge and discharge energy conversion efficiency can be greater than 97%, and lead-acid battery charge and discharge energy conversion efficiency is about 80%, the same lithium battery than lead-acid battery volume Small, the volume of a lithium-ion battery is about 2/3 of the volume of a lead-acid battery;

4.Lithium battery is environmentally friendly, while lead-acid batteries are non-environmental batteries. There is a large amount of lead in lead-acid batteries. If it is improperly disposed of after disposal, it will pollute the environment. Under the same voltage and capacity, lithium batteries and Lead-acid batteries have the same cruising range, but lithium batteries are more than twice as expensive as lead-acid batteries;

5.Lead-acid is significantly damage the environment due to its production process or discarded batteries. The national policy has restricted the reinvestment of lead-acid batteries or restricted the use in some areas. In the future, the trend of replacing lead-acid batteries with lithium batteries will become more obvious, and the progress will be gradually accelerated. Many lead-acid batteries will be replaced by lithium batteries, so lead-acid batteries are slowly withdrawing from the lithium battery stage.

The path of Lithium battery

The lead-acid battery has a low cost and low internal resistance. There is not necessary to protect the circuit, it can be virtually maintenance-free, but with the growth of the lithium battery, the path of the lead-acid battery is narrow. Today, the standard is all lithium batteries, although the mistakes are well known, bulging, burning explosions and other issues emerge one after another, but until now, there is still no battery that can span lithium batteries in terms of capacity and charging times.

Fig.2

Both lithium batteries and lead-acid batteries are energy storage batteries, but they also rechargeable batteries with completely different characteristics, so they cannot be used together unless they can be used separately, but must meet the technical requirements, including protective measures.

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