All androids, no matter which type, are defined by their unlimited stamina.  This allows them to never require sleep and never get exhausted.  You gain immunity to exhaustion and don’t require sleep.

Due to being created by something, all androids have a certain level of respect for their creator.  This is dependent on what type of android they are.  This usually makes their alignment the same as their creator.  This makes them immune to any alignment changes that stray from their creators.  The only exception to this is semi-mechanical androids, who have the same alignment as the creature they originally were. 

Mechanical and semi-mechanical android naturally loose the ability to suddenly charge Ki due to their inorganic bodies.  As such, they have energy-chargers built into them.  The usual type of energy charger is a nuclear core, but can really be anything.  With this, you gain back any abilities (Things like action surge and bardic inspiration) that require long rests over time.  After 2 hours of non-strenuous activity or rest, you will gain 1d6 uses of the ability.  Rolling more than the limit will instead have the amount of uses cap off at the limit.

While fully mechanical androids lack the ability to use Ki, they can absorb it to generate power and even send attacks back.  As a reaction, against an energy based attack(including spells), you can choose to absorb the attack.  When you can do this, you can either heal yourself equal to the damage that would’ve been dealt, or you can fire it back at the attacker, dealing the same damage it would’ve done to you.  When you return the attack, it always hits.  The DC is equal to the attackers DC

You can use it three times per Ki well reset.

Due to your mechanical physical prowess and intelligence, you gain a +2 to either strength or constitution and a + 1 to either intelligence or wisdom.  Additionally, you can make an investigation or perception check before a battle.  If it is higher than the targets AC, you can learn one thing about the creature whether an attack, it’s total HP,  or how threatening it is.