18650 button top protected batteries are a type of rechargeable lithium-ion battery with a button on the positive end that protrudes slightly from the battery casing. This button helps to ensure that the battery fits securely in devices that require a tight fit or have spring-loaded contacts. The protected circuit on the battery helps prevent overcharging, over-discharging, and short-circuiting, which can damage the battery and cause it to fail prematurely.

Protected batteries are ideal for use in high-drain devices such as flashlights, digital cameras, and other portable electronics that require a reliable power source. They have a capacity of up to 3500mAh, providing long-lasting power and reducing the need for frequent recharging. When used properly and with compatible chargers, these batteries can provide years of reliable service.