With the acceleration of the aging society and the increasing travel needs of people with disabilities, electric wheelchairs, as essential mobility aids, rely on batteries as their core power source. The performance of these batteries directly impacts the user experience. Currently, lithium batteries and lead-acid batteries are two commonly used battery types in electric wheelchairs. They exhibit significant differences in energy density, endurance, service life, safety, and other aspects, which determine their suitability for different application scenarios in electric wheelchairs.
1. Energy Density and Portability
Lithium batteries have a significant advantage in energy density. For instance, common lithium iron phosphate batteries can achieve an energy density of 130 - 160Wh/kg, while that of lead-acid batteries is only 30 - 50Wh/kg. This disparity in energy density means that for the same power requirement, lithium batteries are smaller in size and lighter in weight. Take an electric wheelchair equipped with a 24Ah battery as an example. If a lead-acid battery is used, it may weigh as much as 15 - 20kg, whereas a lithium battery of the same capacity can reduce the weight to 3 - 5kg. For users who frequently need to fold and carry their electric wheelchairs, such as when traveling by car or plane, the lightness of lithium batteries greatly enhances portability and eases the burden on users and their caregivers during handling. Additionally, the smaller size of lithium batteries allows for more flexible placement within the electric wheelchair, facilitating the optimization of the wheelchair's overall structural design.
2. Endurance
In terms of endurance, lithium batteries can provide more sustained power for electric wheelchairs due to their high energy density. Generally, for lithium batteries and lead-acid batteries of the same capacity, the cruising range of an electric wheelchair powered by a lithium battery can be increased by 30% - 50%. For example, when an electric wheelchair is equipped with a 48V/12Ah lead-acid battery, its cruising range is approximately 20 - 25 kilometers. However, after replacing it with a lithium battery of the same voltage and capacity, the cruising range can reach 28 - 35 kilometers. For users who need to go out for long periods, such as attending social gatherings or visiting parks, the longer endurance of lithium batteries reduces the embarrassment of running out of power midway and enhances the convenience and autonomy of travel.
3. Service Life and Maintenance Costs
Lithium batteries generally have a longer cycle life. The number of charge-discharge cycles of common lithium-ion batteries can reach 500 - 1000 times, and some high-performance lithium iron phosphate batteries can even exceed 2000 cycles. In contrast, the cycle life of lead-acid batteries is usually only 200 - 300 times. Assuming an electric wheelchair user charges and discharges the battery once a day, a lithium battery may only need to be replaced every 3 - 5 years, while a lead-acid battery may need replacement every 1 - 2 years. Frequent battery replacement not only increases economic costs - a 48V/12Ah lead-acid battery costs about 300 - 500 yuan, while a lithium battery is more expensive, around 1000 - 2000 yuan - but considering the replacement cycle, the long-term comprehensive cost of lithium batteries is actually lower. Moreover, lead-acid batteries require regular inspection and replenishment of electrolyte during use, which is quite cumbersome. Lithium batteries, on the other hand, are basically maintenance-free, further reducing usage costs and the operational burden on users.
4. Safety
Lithium batteries and lead-acid batteries each have their own safety characteristics. Lithium batteries do not contain harmful heavy metals such as lead, mercury, and cadmium, resulting in less environmental pollution during production, use, and disposal. However, lithium batteries pose safety risks such as fire and explosion in cases of overcharging, over-discharging, or short circuits. Nevertheless, with the continuous advancement of Battery Management System (BMS) technology, advanced BMS can monitor parameters such as battery voltage, current, and temperature in real-time. Once abnormal conditions are detected, immediate protective measures, such as cutting off the circuit or adjusting the charging current, are taken to effectively reduce safety risks. Although lead-acid batteries are less likely to cause severe combustion or explosion accidents, their production process consumes a large amount of lead resources. If not properly disposed of after being discarded, heavy metals like lead can cause serious pollution to soil and water sources. Additionally, the electrolyte of lead-acid batteries is corrosive and may harm humans and the environment if it leaks.
5. Cost
Currently, the initial purchase cost of lithium batteries is significantly higher than that of lead-acid batteries. Taking a 48V/12Ah battery as an example, a lead-acid battery costs 300 - 500 yuan, while a lithium battery costs 1000 - 2000 yuan. This makes lead-acid batteries more appealing to price-sensitive users. However, as mentioned before, considering the long service life and low maintenance costs of lithium batteries, their comprehensive cost is more competitive from a long-term usage perspective.
6. Adaptation to Practical Application Scenarios
Based on the above characteristics, lithium batteries are more suitable for users who have high requirements for portability, endurance, and service life and have a relatively sufficient budget, such as electric wheelchair users who often travel or are frequently engaged in social activities. Lead-acid batteries, on the other hand, are more suitable for users who are price-sensitive, have a low usage frequency, and have a small activity range, thanks to their lower initial cost. For example, an elderly person who mainly stays at home and only occasionally moves around the neighborhood can meet their basic needs with an electric wheelchair powered by a lead-acid battery. However, for a young person with disabilities who often participates in outdoor activities and values travel convenience, an electric wheelchair with a lithium battery is a better choice.
Lithium batteries and lead-acid batteries each have their own advantages and disadvantages in the application of electric wheelchairs. With the continuous development of lithium battery technology and the gradual reduction of costs, lithium batteries are expected to play a more dominant role in the field of electric wheelchairs in the future, bringing users a more high-quality, efficient, and environmentally friendly travel experience.