Although it owns its own battery factory, Samsung is said to have chosen a Chinese supplier to deliver the batteries for the next Galaxy S21 flagship.
As a global smartphone maker, Samsung is already turning to the services of several battery providers. The strategy of not being its own sole supplier of batteries, through the Samsung SDI division, is motivated both by cost criteria and stock availability. It is simply more efficient in certain situations to procure the necessary components from external suppliers than to produce them in our own factories.
Galaxy S21 phones, delivered with 4000 and 5000 mAh batteries
In this case, the battery supplier selected for the Galaxy S21 series would be Amperex Technology Limited, a Chinese manufacturer that has collaborated with Samsung in the past. Most likely, it will only supplement the deliveries of batteries produced in Samsung SDI factories, ensuring that component stocks will not limit production in any way.
On a hierarchical scale, Amperex holds 17.1% of the global battery market, followed by Samsung SDI with 28.4% market share and LG Chem with 19.5%.
Theoretically, the brand of battery used should not influence in any way the perceived performance, all the components used going through an extremely strict validation process. Thus, the standard Galaxy S21 model comes with a 4000mAh battery, while the S21 Ultra version is chosen with a 5000mAh battery, or 4500-4800mAh (according to other rumors).