THUNDERBIRD 2 KM SOLAR ENERGISER ** CLEARING ****LAST ONE** once it's gone, it's gone. With Built in Rechargeable Battery Pulse Operation light Compact and very portable Easy and fast to set up Earth and Fence leads supplied Solar 2 uses a NiMH battery that can be left flat for long periods without being damaged. If the battery is flat, simply place it in the sun for a few minutes and it will start to operate. Super effective Solar to Battery system only requires 3 hours of sun a day. To install