Paul Buff is talking about the circuit protection circuits on the battery/charger. In lithium cells, you have protection circuits to prevent undercharging and overcharging. In your laptops, the lithium cells are about 4 VDC, so there is three of them to make the 12VDC pack ; while the VLX are about 3.1 VDC so they use four to make 12VDC. So you have to match the right transistor for the charging.
To me, that Nomad seems to have the same specs as the VLX... I think PCB did have trouble sourcing the battery from China, so I thought Interfit bought several months of product from the same factory as PCB. Hence, they have the same specs. So I am waiting to see if I can see pictures of the Internet product, so I can see if it is really the same stuff.