The 3.7V Li-Ion polymer battery has a typical charge cut-off voltage of 4.2V and a minimum discharge cut-off voltage of 2.8V. There are various common capacity specifications, including 250mAh, 320mAh, 650mAh, 850mAh, 1000mAh, 2000mAh, and 3700mAh. Batteries of varying capacities can be supplied to meet the specific battery requirements of different devices.For instance, small electronic toys usually utilize batteries with a capacity ranging from 250mAh to 650mAh. In contrast, some larger portable speakers are likely to be equipped with batteries having a capacity of 2000mAh or more, enabling them to operate for an extended period without frequent recharging.