[Wide Compatibility] The USB lithium-ion rechargeable batteries are designed with standard AAA battery size, which has high compatibility. It can be widely used in different devices such as alarm clocks, mice, wireless keyboards, toys, digital cameras, flashlights, calculators, shavers, fans, household products, etc,. [Note: Please charge the batteries before the first time use. These rechargeable batteries were not fully charged when you received them.]. [LED Light Indicator] There is a built-in light indicator on the rechargeable battery. When the battery is recharging, the Charging-Green light will flash. After fully recharged, the Charged-Green light will be on. You can quickly judge the charging status of the battery through the LED light indicator, and do not need to keep your eyes on it all the time. [Quick Charge and Safety Protection] HW rechargeable battery can be fully recharged within 1 hour, which only needs 40 minutes under the best condition. Multiple over-charger protection makes it safe and reliable, including over-charging, over-discharging, over-voltage, over-temperature, over-current, short circuit and undervoltage. HW always provide customers with safe and reliable rechargeable batteries. [USB Charging Design with 1000+ Recycling Times] The Lithium-ion rechargeable battery has built-in micro USB port, which allows you to be recharged from the PC, desktop, wall plug, power bank through the included USB charging cable. You do not need extra battery charger. More than 1000 cycle times. Compared to non-rechargeable batteries and rechargeable batteries with less cycles, HW batteries not only save you time and money to repurchase a regular battery, more important significantly reduces pollution to our lived environment. [600mWh Lithium Battery] HW USB rechargeable AAA battery has 600mWh capacity.Constant output 1.5V, Embedded with innovative technology,solid output 1.5 voltage from 100% to 0% electric capacity, providing constant voltage and best performance even in very heavy load. Great use for high-power demand device like Insulin pumps, Game Controller, Bluetooth Earphone, Electric Toothbrush, Flashlights,Portable audio players etc.