How to choose between lead-acid batteries and lithium batteries, what are the differences, and which is safer?

How to choose between lead-acid batteries and lithium batteries, what are the differences, and which is safer?

Many users always encounter the choice between lead-acid batteries and lithium batteries when purchasing batteries, and because lithium batteries are much more expensive than lead-acid batteries, they choose lead-acid batteries. They rarely analyze and judge before making a choice. Some intuitive choices are that lithium batteries are lighter in weight, so they choose lithium batteries directly, but they do not fully understand the real differences between them. So here, we will explain to users clearly, so that they will know how to choose battery types in the future.

Lithium batteries and lead-acid batteries have almost the same application fields, not only for power batteries, but also for energy storage. However, their essential differences lie in the following aspects.

In terms of power battery applications:

For the same battery capacity, lead-acid batteries are more than three times heavier than lithium batteries. In electric vehicle applications, lithium batteries can reduce the weight of the vehicle body, which is of great help for extended travel and easy to transport. We advocate purchasing qualified battery products from reputable manufacturers.

The cost of main materials such as positive electrode materials, negative electrode materials, current collectors, separators, electrolytes, etc. for lithium batteries is much higher than that of lead-acid batteries. The assembly materials and external circuit system costs of lead-acid batteries are extremely low.

Due to the manufacturing process, the labor cost of lithium batteries is relatively high. In terms of manufacturing costs, labor costs for lithium batteries account for over 40%, while labor costs for lead-acid batteries are generally between 10% and 20%.

The mechanical equipment used in the production of lithium batteries is expensive and of high value, with significant depreciation and losses. Lithium batteries are mostly irreversible in the production process, while lead-acid batteries are reversible for repair and reuse. The recycling value of lead-acid batteries after use is over 40%, while the recycling value of lithium batteries is almost zero.

Lithium batteries have a volume to energy ratio and weight to energy ratio that is more than three times higher than lead-acid batteries. Lithium batteries are smaller in size, lighter in weight, and have a longer cycle life.

The cycle life of lithium batteries used in electric vehicles is generally over 800 times, and lithium batteries using lithium iron phosphate cathode materials can reach about 2000 times, which is 1.5 to 5 times longer than lead-acid batteries.

This greatly reduces the cost of using lithium batteries, extends their lifespan, and improves their convenience of use. Has a wide range of charging efficiency.

This is a unique advantage of lithium batteries. When needed, the charging time can be controlled within 20 minutes to 1 hour, and the charging efficiency can reach over 84%. On the basis of further technological innovation, this characteristic will be better utilized.

In short, lithium batteries are lightweight, small in size, have a long service life, high charging efficiency, and higher cost-effectiveness. This makes lithium batteries almost a large part of electric vehicle applications, and this proportion will further increase.

Application areas of energy storage batteries:
We know that generally comparing energy storage products should be done from the perspectives of weight energy density, volume energy density, service life, price, applicability, national policies, etc.:
1. Weight energy density
At present, the energy density of lithium batteries is generally between 200-260 Wh/g, while lead-acid batteries are generally between 50-70 Wh/g. Therefore, the weight energy density of lithium batteries is 3-5 times that of lead-acid batteries. This means that under the same capacity, lead-acid batteries are 3-5 times that of lithium batteries. Therefore, in terms of lightweight energy storage devices, lithium batteries have an absolute advantage.
2. Volume energy density
The volumetric capacity density of lithium batteries is usually about 1.5 times that of lead-acid batteries, so for the same capacity, lithium batteries are about 30% smaller in volume than lead-acid batteries.
3. Usage cycle
The currently popular material systems are ternary and iron lithium. The cycle times of ternary power type lithium batteries are usually over 1000 times, the cycle times of lithium iron phosphate batteries are over 2000 times, and the cycle times of lead-acid batteries are usually only about 300-350 times. Therefore, the service life of lithium batteries is about 3-6 times that of lead-acid batteries.
4. Price
At present, lithium batteries are about three times more expensive than lead-acid batteries in terms of price. However, based on the analysis of their service life, even with the same cost, the service life of lithium batteries is still longer.
5. Applicability
Lithium batteries are slightly less safe than lead-acid batteries, so various safety precautions need to be taken during use, such as preventing external forces or accidents from damaging lithium batteries, as this may cause fire or explosion; At present, the temperature adaptability of lithium batteries is also very good, so in other aspects of adaptability, lithium batteries are not inferior to lead-acid batteries.
6. National policy
Lead acid batteries pose a significant threat to the environment due to their production process or discarded batteries. Therefore, from a national policy perspective, there are already restrictions on the expansion and reinvestment of lead-acid batteries, or on their use in certain fields. In the future, the trend of replacing lead-acid batteries with lithium batteries will become increasingly apparent, and progress will gradually accelerate. 
7. In terms of durability
Lithium batteries have strong durability, slow consumption, over 500 charge and discharge cycles, and no memory. Their general lifespan is around 4 years? 5 years. Lead acid batteries generally have a memory and a lifespan of about two years after being deeply charged and discharged within 400 times. If using maintenance free lead-acid batteries, it should be noted that the battery loses less water and generally does not require the addition of distilled water during use. In terms of durability, lithium batteries have good shock resistance, and fully charged batteries are securely fixed. They vibrate at a frequency of 16.7Hz for 1 hour with an amplitude of 4mm, without leakage, battery expansion or rupture, and have normal open circuit voltage; Good overcharge resistance, 25 degrees Celsius, fully charged battery with 0.1CA charging for 48 hours, no leakage, no battery expansion or rupture, normal open circuit voltage, and capacity retention rate of over 95%; Good resistance to high current, fully charged battery can be discharged at 2CA for 5 minutes or 10CA for 5 seconds without any conductive parts melting or appearance deformation.
8. In terms of price and warranty period
In terms of price, lithium batteries are more expensive than lead-acid batteries, but their warranty period is longer, which is closely related to their service life.

Based on the above analysis and comparison, do you choose lead-acid batteries or lithium batteries? I suggest that using lithium batteries is the appropriate choice, and it is recommended to choose lithium iron phosphate, which is not only reasonably priced, but also has higher safety. Whether it is power or energy storage, it can still meet the needs of users in these two aspects.