Molicel P45B Battery for EVTOL: Weight v Power Trade Off in Pack Design - How to Pick the Right Balance
Discover the Molicel P45B battery for EVTOL applications, optimising weight and power trade-offs for drone battery design challenges.
Value Propositions
Cylindrical 21700 form factor for efficient design.
Nominal capacity of 16.2 Wh and 4.5 Ah for reliable performance.
Top-quartile volumetric energy density of 633 Wh/l for compact designs.
Maximum continuous discharge of 45 A, ideal for high-demand applications.
Gravimetric power density of 2314 W/kg, supporting rapid energy delivery.
About the Cell
The Molicel P45B is a cylindrical 21700 cell with a nominal capacity of 16.2 Wh and 4.5 Ah, making it suitable for various UAV applications. It boasts a volumetric energy density of 633 Wh/l, which is in the top-quartile compared to the database median of 541.67 Wh/l, providing a compact solution for drone battery design. The gravimetric energy density of 231.429 Wh/kg is also competitive, being around the median of 210 Wh/kg. With a maximum continuous discharge of 45 A, this cell is designed to handle the high current demands typical in UAV operations. Additionally, the volumetric power density of 6330.6 W/l is among the highest in the database, enabling efficient power delivery during critical phases of flight. These specifications make the P45B an excellent choice for applications requiring a balance of weight and power.
Application Challenges
In EVTOL applications, the weight versus power trade-off is crucial for optimising battery pack design. The Molicel P45B addresses this challenge by providing a high energy density that allows for longer flight times without significantly increasing weight. The ability to deliver high current outputs is essential for maintaining performance during take-off and manoeuvres. As UAVs are often deployed in demanding environments, ensuring that the battery can withstand varying temperatures and discharge rates is vital. The P45B's specifications help mitigate risks associated with overheating and ensure reliable operation across different mission profiles, making it a suitable choice for both commercial and industrial UAV applications.
Why this Cell
The Molicel P45B is specifically designed for UAV applications, offering a nominal capacity of 16.2 Wh and a maximum continuous discharge of 45 A, which is top-quartile compared to the median of 30 A in the database. This capability is essential for applications requiring high discharge rates, such as heavy-lift drones. The volumetric energy density of 633 Wh/l allows for a compact battery design, which is crucial for maintaining the overall weight of the UAV. Furthermore, the gravimetric power density of 2314 W/kg supports rapid energy delivery, ensuring that the drone can perform efficiently during critical operations. These features make the P45B an ideal choice for optimising the weight versus power trade-off in battery pack design.
How Model-Based Design Helps
Simulation and model-based design play a pivotal role in selecting the right battery for UAV applications like the Molicel P45B. By simulating load profiles, engineers can predict how the battery will perform under various conditions, including thermal rise and voltage sag. This predictive capability allows for the identification of the optimal battery specifications needed to meet mission requirements without compromising safety. For instance, modelling can help determine the maximum continuous discharge rates and how they affect overall battery performance during flight. Additionally, simulations can assess the usable energy across different temperatures and states of charge (SoC), ensuring that the selected cell can reliably deliver the required thrust and energy throughout the entire flight envelope. This approach reduces the risk of mid-air failures and enhances operator confidence in mission readiness.
