By converting solar energy into electricity, the solar panel charges the battery during the day and the built-in sensor turns on the light automatically at dusk.
If no enough sufficient sunshine, you can just replace the rechargeable AA battery and it will work. Note, the replacement battery should also be rechargeable. Specifications:

- Total Length: 4.75M/ 15.6ft, distance between each light is 5.9inch/ 15cm; power cord length: 1.9meters/ 6.2ft; the Heart LED diameter: 3cm/ 1.2inch
- Solar panel: 6.8*6.8*2.4cm; 1.2V 100mAh
- Solar powered panel is With ON/OFF, MODE switches
- 2 different lighting modes: Steady on and twinkling
- Voltage: 2V
- Wattage: 0.03W
- Working time: can support 8-10 hours after fully 6 hours charging, Life more than 10,000 hours

Package includes:

1*20 LED Crystal Heart Shaped Lanterns Light
1*solar panel
2*Mounting brackets
1*manual

• Total approx. 15.6ft, 20 LED each one space 5.8inch/ 15cm, length of power cord 6.2ft/1.9 meter, the Heart LED diameter: 3cm/ 1.2inch
• Automatically turn on at dusk and turn off at dawn under on mode. If no enough sufficient sunshine, you can just replace the rechargeable AA battery and it will work. Note, the replacement battery should also be rechargeable
• Uniquely heart designed 20LED string lights, environment-friendly powered by solar with a high-performance solar panel kit, energy-saving and eco-friendly
• Can work 8~10 hours after fully 6 hours charging, life more than 10,000 hours. 2 modes (Steady on and twinkling) and 2 switch modes (ON / OFF & Flash)
• Fully waterproof, can be used indoor or outdoor. Great decoration for your gardens and porch by hanging the string light among the shrubs, trees and other areas, ideal for party, wedding, Christmas etc. Note: the lights may get rusted outside, but that will not affect the look in the night.

Total approx. 15.6ft, 20 LED each one space 5.8inch/ 15cm, length of power cord 6.2ft/1.9 meter, the Heart LED diameter: 3cm/ 1.2inchJOJOO