Molicel P42A 21700 (4200mAh)

Molicel might not be a household name the way Panasonic or Samsung are, and that is exactly what makes it worth discovering. This Taiwanese manufacturer has spent years specialising in a single niche, and it excels at it: high-drain lithium-ion cells capable of delivering huge instantaneous current without sagging or overheating. Among enthusiasts of powerful torches and demanding cordless tools, the Molicel name carries serious weight, quoted far more often on specialist forums than mainstream consumer brands.

The P42A is the 21700 version of the famed P26A, carrying the same philosophy to a bigger format. This cell offers 4200mAh of capacity (4000mAh guaranteed minimum), trailing the 5000mAh of the best “high-capacity” 21700 cells on the market, but that is not what it is built for: its real strength is a 45A continuous discharge rating, one of the highest in the format. In practice, it can power a very demanding cordless tool, an ultra-powerful torch or a demanding DIY pack without ever throttling performance, where a classic high-capacity cell would overheat or see its voltage collapse.

Technically, the P42A has a nominal voltage of 3.6V, a maximum charge voltage of 4.2V and a discharge cut-off of 2.5V, in a Flat Top (flat positive terminal) format measuring 21.7 x 70.2mm. It is sold bare, with no protection circuit: like any cell of this type, it is intended for experienced users comfortable with the usual precautions (a dedicated lithium-ion charger, no short-circuiting, storage in a case, staying within the voltage range).

The P42A remains, to this day, one of the most recommended 21700 cells in the high-drain community, with a reliability track record proven over several years. Molicel now also offers the P45B, higher in capacity at an equivalent discharge rating, but the P42A remains a trusted choice for anyone who wants current above all.