The Molicel P50B packs 11% more capacity than the P45B into the same 21700 form factor. At pack level, that translates to lower operating currents, better thermal headroom, and up to 50% longer cycle life in our testing. But is it a straightforward drop-in replacement? We ran both cells through electrical, 2D thermal, and degradation models to find out.

Explore About:Energy’s case study on the Molicel P45B (also known as Molicel P45B INR21700) battery cell. The article examines its role in powering record-breaking electric vehicles like the McMurtry Spéirling and highlights key insights into thermal performance, system design, and battery testing for high-performance applications.