I open the brand new Librem 14 freshly received.
There are two slots for Nvme hard dirves on this hardware, one is on the right side and the other one is behind the large battery.
Is it ok to install an additional Nvme and put the battery over it ? it may cause some damage I guess ?
which means that the second nvme can’t be used ?
Yes. Even if it fits, NVME drives get very hot. The 2nd slot is only usable if you get a 3S battery from Purism. If that’s something you’re interested in, email support and ask them if you can buy one.