The 3 km solar energizer comes with an internal battery which has a 2 year factory warranty.

This energizer offers the following features:
• Robust solar bracket and weather-resistant housing
• On/off TAG to switch the energizer on and off
• Battery charge state indicator
• Solar panel charge state indicator
• Deep sleep mode for battery safe mode storage
• Day/night sensor
• Star picket mounting
• Lightning protection
Specifications

• Energy: 0.26 Joules output. 0.33 Joules stored
• 5 Watt solar panel included
• Built-in solar regulator: Advanced MPP power
management system