The battery packs aren’t a huge contributor to the total assembly cost of a phone (that would be the display) but every lit bit of fat trimming counts. A typical phone battery costs $6-$8 but when you mass produce, every bit counts.
Samsung is trying to popularize the foldable phones niche and for them to become mainstream the bendy handsets need to fall in price at least to the level of current rigid flagships, so the ATL and LG battery supply diversification spree over at Samsung is one piece of its market penetration puzzle.
One way to achieve lower Galaxy Z Fold 4 and Z Flip 4 prices yet still add new features and hardware to the phones is by replacing expensive suppliers in the chain with alternatives that are no less experienced but can produce the component for less and Samsung seems to be doing exactly that.
