Lithium battery charger How do you distinguish it from a lead‑acid battery charger? What are the differences? When we think of lead‑acid battery chargers, the first application that comes to mind is electric bicycles. In fact, based on their structure and intended use, the industry divides lead‑acid batteries into four main categories: 1) starting batteries; 2) traction batteries; 3) stationary valve‑regulated sealed batteries; and 4) small valve‑regulated sealed batteries. This classification focuses primarily on structural characteristics while also considering applications, which can still be challenging for those outside the battery field to grasp. A more straightforward approach is to categorize them purely according to market applications; under this criterion, lead‑acid batteries fall into two broad types:
1. Main power supply, including: communication equipment, industrial instrumentation, electrically controlled machine tools, and portable devices;
2. Backup power sources, including emergency equipment, communication base stations, electronic switching systems, and solar energy systems. This classification of applications overlaps significantly with those of lithium‑ion batteries; in terms of market size, such overlap is concentrated primarily in the power‑battery segment, such as electric bicycles and small passenger vehicles. Within the power‑battery sector, the main competition also centers on these two technologies. Therefore, comparing lead‑acid and lithium batteries in this context is highly representative; otherwise, without a clear point of reference, any comparison would be unfocused and inconclusive.
The fundamental differences between the two stem from their distinct material properties: lead‑acid batteries use lead oxide, metallic lead, and concentrated sulfuric acid as the positive and negative electrode materials, whereas lithium‑ion batteries comprise four key components—cathode materials (lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, or ternary materials), graphite anode, separator, and electrolyte. These differences primarily result in the following distinctions:
1. Different nominal voltages: a single lead-acid cell is 2.0 V, while a single lithium cell is 3.6 V.
2. Different energy densities: lead-acid batteries have 30 Wh/kg, while lithium batteries have 110 Wh/kg.
3. Cycle life varies: lead-acid batteries typically last 300–500 cycles, while lithium‑ion batteries can exceed 1,000 cycles. Among the two mainstream technological approaches for lithium‑ion e‑bikes, ternary lithium batteries and lithium iron phosphate (LFP) batteries differ significantly: ternary lithium batteries offer about 1,000 discharge cycles, whereas LFP batteries can achieve up to 2,000 cycles.
4. Charging methods: Lithium batteries employ a constant‑voltage, constant‑current approach, in which both current and voltage are constrained within specified limits. In contrast, lead‑acid batteries offer a wider variety of charging techniques; the principal ones include constant‑current charging, constant‑voltage charging, multi‑stage constant‑current charging, and float charging—though it is not possible to detail them all here.
