This video shows the hot models of li-ion cells and batteries produced by Yichun Topwell Power Co., Ltd. The hot models are 18650 2000mAh 3.7V, 18650 2600mAh 3.7V, 21700 5000mAh 3.7V, 26650 5000mAh 3.7V. These are our advantageous products with CE ROHS UN38.3 etc certified, and our factory is strictly controlled under ISO9001 quality management system.
A fixed outdoor sensor node lives through hot afternoons and cold nights, so its battery pack has to be judged on usable capacity, heat exposure, and protection logic together.
A wide-temperature 18650 cell is only one input, but a shippable pack also needs a BMS, wiring, an enclosure, thermal design, and compliance documents that match the device.
Cold charging behaves like a state machine, where the measured temperature picks a current limit and a termination voltage before the CC/CV loop ever starts.
Topwell Power's IFR21700 cell balances 3.2V, 3000mAh capacity, 9A continuous discharge, and more than 2,000 cycles for durable battery-pack integration.