This is a 10 cell (12VDC) 2200mAhr Rechargeable NiMH battery pack. The batteries are NiMH so they do not have the memory issues common with NiCad battery packs. The batteries are arranged in a 1x10 array of AA batteries interconnected via soldered strips and covered with a PVC wrapping (color may be different than picture). Two wire leads extend out of the pack.
As an option you can select to get connectors for the batteries. The connectors are sometimes referred to as Anderson Powerpole connectors. They can be soldered/crimped onto the wire ends and offer a great way of disconnecting the batteries for charging, etc. The 15A connectors and 30A connectors are the same and can plug into one another, they only are for different gage wires.
This is a 10 cell (12VDC) 2200mAhr Rechargeable NiMH battery pack.
These large Tiller Traction Lug wheels are 13" in diameter. They come as pair and have steel 5/8" diameter shafts and bearings.
The InvenSense MPU-6050 sensor contains an accelerometer and a gyroscope in a single chip. It is very accurate, this sensor is used in self balancing robots, drones, smartphones, etc. The sensor uses the I2C-bus to interface with microcontroller.