How To Calculate Watt Hours
The basic formula is simple:
Watt hours = Voltage × Capacity
Capacity must be converted from mAh to Ah first. For example, a 3V lithium battery with 1500mAh capacity equals 1.5Ah. Its energy is:
3V × 1.5Ah = 4.5Wh
| Battery Example | Voltage | Capacity | Watt Hours |
|---|---|---|---|
| CR123A | 3V | 1500mAh | 4.5Wh |
| CR2 | 3V | 850mAh | 2.55Wh |
| CR14505 | 3V | 2400mAh | 7.2Wh |
| 2CR5 | 6V | 1500mAh | 9Wh |
Why Watt Hours Matter In Sourcing
Watt hours affect device runtime, battery pack design, carton labeling, and transportation review. For lithium batteries, international shipping usually requires UN38.3 test documents, MSDS, proper packaging, and clear battery information. This is why buyers should not only compare capacity, but also confirm voltage, chemistry, discharge current, working temperature, and certification documents.
Manufacturer Vs Trader
A trader may provide different battery models, but may not control cell consistency, capacity grading, internal resistance, safety testing, or batch traceability. A direct manufacturer can manage material selection, cell production, testing, packing, and shipment documents more effectively.
Hongli focuses on primary lithium manganese batteries and battery pack solutions. Our products include CR123A, CR2, CR14250, CR14505, CR17450, CR17505, CRP2, 2CR5, CRV3, CR9V, 3V button cells, and customized lithium battery packs.
OEM ODM And Quality Control
OEM / ODM projects can include battery model selection, wire connector, plug type, housing, label, shrink wrap, packing method, and discharge requirement. Key quality checkpoints include open circuit voltage, capacity, internal resistance, leakage inspection, high-low temperature performance, safety testing, and batch records.
For bulk orders, buyers should confirm watt hours, application load, storage life, MOQ, lead time, packaging, export documents, and compliance requirements. Hongli can support stable production, customized battery pack development, and export-ready lithium battery supply for industrial and commercial applications.