Amazon.com: 6GTPY Laptop Battery 97Wh for Dell XPS 15 9560 9550 Precision 5510 5520 M5520 Replacement for 5XJ28 i7-7700HQ 5D91C Laptop [Longer Model Not for Laptop with SDD/HDD] : Electronics
i did it. XPS 15 9560 with 56Wh battery and 1TB secondary hard drive in place of the 97Wh battery : r/Dell