18650 lithium-ion cells have become the mainstream modular power source for modified, customized and lightweight electric tricycle batteries in recent years, replacing integrated factory lithium batteries and traditional lead acid battery packs for modified tricycles, folding cargo tricycles and sightseeing tricycles. Standard 18650 cells adopt cylindrical 18mm*65mm size specifications, with single nominal voltage 3.7V and mainstream capacity ranging from 2000mAh to 3500mAh. Compared with integral lithium batteries, 18650 cell assembled tricycle batteries feature flexible combination design: assemblers adjust series-parallel quantity freely to form 60V, 72V high-voltage battery packs matching tricycle motor parameters. This modular design brings prominent maintainability, as users only replace damaged single cells instead of the whole battery pack, greatly cutting post-fault maintenance cost for private tricycle owners and repair shops.

Scientific series-parallel grouping and complete BMS configuration are the premise of safe 18650 tricycle battery assembly. To reach common tricycle working voltage, 16pcs 18650 cells in series form a 60.8V full-charge 60V battery pack, and 20pcs cells in series form a 74V full-charge 72V battery pack, with parallel groups increasing overall discharge capacity for longer mileage. Only grade-A industrial 18650 cells are qualified for tricycle power use; recycled disassembled cells have inconsistent internal resistance, causing thermal runaway and cell burnout during high-current discharge. Every assembled 18650 tricycle battery must be equipped with a dedicated lithium BMS board, which realizes over-charge protection, over-discharge protection, over-current protection and temperature protection. For cargo tricycle use, high-rate discharge 18650 cells are required to support instant high current output during uphill and heavy-load startup, different from low-rate cells for energy storage lamps.