The seeeduino is an arduino clone and has very similar specs.
- Microcontroller____ATmega168
- Operating Voltage_____5V/3.3V
- Input Voltage (recommended)_____7-12 V
- Input Voltage (limits)_____6-20 V
- Digital I/O Pins_____14 (of which 6 provide PWM output)
- Analog Input Pins_____8
- DC Current per I/O Pin_____40 mA
- DC Current for 3.3V Pin_____50 mA
- Flash Memory_____16 KB (of which 2 KB used by bootloader)
- SRAM_____1 KB
- EEPROM_____512 bytes
- Clock Speed_____16 MHz
Just follow the traces from the connector to the header on the board that has the voltage and ground labels.
As with all electronic devices the pin labeled Vin is for positive voltage input. So if your plugging in a battery pack the positive lead goes to Vin and the negative lead goes to ground. So any battery pack that supplies between 7 and 12 v can be connected there or at the power connector.