With the development of battery technology, people's requirements for electric vehicle usage experience have also become increasingly high. In the past, electric vehicles needed to be charged overnight or at least for 8 hours to be fully charged. In recent years, however, lithium-ion battery fast-charging technology has emerged, enabling electric two-wheelers to achieve a range of 100 kilometers with just 15 minutes of charging! But currently, only lithium-ion batteries can achieve this. So, why can't lead-acid batteries reach such fast charging speeds? There are four main reasons:

First, high cost of fast charging

Lead-acid batteries are typically used in low-to-mid-range vehicles, while high-end electric vehicles employ lithium-ion batteries. To achieve fast charging for lead-acid batteries, ordinary chargers are insufficient and customized fast-charging chargers are required, which can cost 5-10 times more than regular chargers. Additionally, the internal structure and composition of lead-acid batteries need to be upgraded, and the production process must be refined. These factors significantly increase the manufacturing cost of vehicles. Currently, graphene lead-acid batteries support 2-hour fast charging. They use graphene materials for both positive and negative electrodes, reducing resistance and minimizing battery heating, thereby avoiding excessive water loss. However, achieving a 30-minute full charge for lead-acid batteries is technically challenging at present.

Second, shortened battery life

Lead-acid batteries typically have a cycle life of around 500 times, and even graphene batteries only reach around 800 times. Using fast charging accelerates the cyclic loss of the battery due to high currents, potentially leading to battery swelling, plate sulfation, and even battery failure. Even with safe fast charging, batteries may still heat up and lose water more quickly, ultimately reducing their lifespan.

Third, lack of necessity for fast charging in lead-acid batteries

For household electric vehicles used primarily for commuting within a 10-kilometer range, the current 48V20ah batteries can already provide a range of 40-50 kilometers, which is generally sufficient. Slow charging overnight is convenient and does not require urgency. Unless for delivery riders who need to cover more distance, fast charging might be considered. However, with the emergence of battery swapping cabinets, delivery riders now often opt for direct battery swaps instead of fast charging. Thus, there is limited demand for fast charging in lead-acid batteries.

Fourth, potential safety risks associated with fast charging

Although lead-acid batteries do not explode, fast charging involves high currents that can cause devices to overheat and potentially catch fire if internal components of the charger fail. This poses a fire risk, especially if fast charging is performed overnight.

In summary:

From a chemical perspective, lead-acid batteries have lower energy density and higher resistance compared to lithium-ion batteries. Fast charging requires batteries to absorb a large amount of electrical energy in a short time, which can be challenging for lead-acid batteries due to their limited capacity. In contrast, lithium-ion batteries have more active chemical properties, higher energy density, and lower resistance, enabling them to accept large amounts of electrons quickly during fast charging. Therefore, lithium-ion batteries outperform lead-acid batteries in terms of fast charging capabilities. What are your thoughts on this? We welcome your comments!

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