Lithium-ion battery pack capacity depends on the capacity of each cell and the number of cells connected in parallel. Series connections increase voltage but normally do not increase amp-hour capacity, while parallel connections increase capacity and current capability. This guide explains how to calculate battery pack capacity in mAh, Ah and Wh, with practical examples for 1S1P, 2S1P, 1S2P, 2S2P, 3S2P and other configurations. It also explains the difference between rated capacity, usable capacity and energy, and highlights common calculation mistakes involving voltage, cell matching, temperature, discharge conditions and battery protection limits. The goal is to help OEM engineers and buyers prepare accurate lithium-ion battery pack specifications.
Lithium-ion battery pack design requires more than selecting a cell with a target capacity. OEM engineers must match voltage, energy, current demand, runtime, BMS functions, dimensions, connectors and operating conditions with the host device. This guide explains how these factors work together during battery pack design. It also provides practical examples using 3.7 V cells, series and parallel configurations, capacity calculations and runtime estimates. Detailed topics such as capacity formulas, runtime calculations, connectors, battery-compartment tolerances and BMS communication are linked to more focused resources instead of being repeated in full. The goal is to help product teams prepare a clearer battery specification before requesting a custom lithium battery pack.
Choosing a lithium battery manufacturer requires more than comparing price and capacity. OEM buyers should evaluate the supplier’s engineering capability, cell sourcing, production controls, testing procedures, documentation, traceability, certifications, change management and after-sales support. This lithium battery manufacturer quality checklist provides a structured way to review suppliers before approving samples or mass production. It also explains which documents and practical evidence buyers should request, why certificates alone do not prove product quality and how to compare manufacturers, pack assemblers and OEM/ODM suppliers based on actual responsibilities. The goal is to help product, engineering, procurement and quality teams reduce supply risk and select a battery partner capable of delivering consistent performance over the full product lifecycle.
