Talk to an Angaran Mechanic in warehouse adjacent to the hangar in the northwestern part of the Resistance Base and he’ll freely hand over a schematic, which he claims will upgrade the Nomad’s shielding. To finish this simple task all you need to do is visit any Research Station and spend the necessary resources - 120 Iron, 40 Nickel and 30 Platinum (ouch!) to develop this “Improved Shield Regeneration” upgrade.