LiPo batteries power the T200 thrusters and the Pixhawk. According to Blue Robotics, the T200 thrusters are optimized for use with a 4S LiPo (16 V). However, the T200 thrusters can operate at voltages ranging from 7-20 V. We chose a 4S LiPo based off the information provided by Blue Robotics and it works great. That said, it appears that you have some flexibility when choosing a battery.
Safety
LiPo batteries are very popular with the drone and RC community because of their light weight and high capacity. Despite their popularity, they can pose a serious risk to life and property and there are many YouTube videos of LiPo fires and explosions.
Damaged or over-charged LiPo batteries can cause fires or explosions. Never use a LiPo that has been damaged, dropped, or over-charged. Always heed manufacturer warnings and best practices. Inspect LiPo batteries before and after each use and before and after charging. If the battery is “puffy” dispose of it immediately (consult your relevant authority for hazardous waste disposal). Never discharge a LiPo battery below 3.7 V. Never leave a LiPo unattended when charging and use a LiPo safe bag. If a LiPo ever catches a fire it is a chemical fire so have an appropriate fire extinguisher next to your charging station.
Charging and Discharging
Check your LiPo battery’s ‘C’ rating. The C rating tells you how much current (Amps) you can safely draw without causing damage to your battery. For example, the 4S 5000 mAh LiPo that we use in the Maker Boat Basic has 50C rating. That means that we could draw up to 250 A from this battery without causing any damage. Nothing on the Maker Boat Basic should ever draw this much current, so we can be fairly confident that the battery will not be damaged during normal use.
When charging LiPos, make sure you use a balanced charger to ensure that any voltage differences between cells are very small. Stick to the manufacturer guidelines when charging, or charge at 1C. For the 5000 mAh LiPo battery, charging at 1C means charging at 5 A.