Are you saying that between fights a ship you encountered healed 102 dmg or it healed 102 dmg while fighting in the battle viewer?
If a ship has 100 hit points but also has 25 each of the defenses, those defenses will go first. They also fully return each engagement in the battle-viewer. Hit points do not, they slowly regenerate unless you have the end line ship repair module in it. That module requires thulium and heals quite a bit DURING combat. It is a late game module and I have yet to see the ai have it installed.
First thing I've noticed is that the battle viewer only registers damage that affects the ship; if a defense module blocks an attack or it misses (which happens a lot, they have a jamming perk ) then no damage is reported after a battle for that attack. Second thing, is that none of their ships have modules that repair in-combat but all of them manage to. Every design usually has one shield, 1-2 chaff, 6-8 railguns, and an enhanced reloader (or whatever it's called).
My ship had 18 beam attack (recharger dropped 15% damage) and the enemy ship had 6 shielding. Shields weren't the problem either (especially considering how fast he wore through 52 armor).
I also just attacked another ship (saved this time first... ) with a fighter with 10 beam attack and a destroyer with 18 kinetic attack; that ship had 22 health and 6 shields, plus 0 armor; they managed to survive 102 damage and actually gained 45 health. Ships also should never be able to heal more damage mid-battle than they started with in health (let alone 5x as much).
If I attack with 2 bigger ships I'll almost always win with no damage, but if I attack one on one (or 2 small on one medium) with anything but overwhelming superiority (aka durantium drivers or elerium beams) I take a ton of damage if I even manage to win.