The E-Coal armor in its current state isn't really worth using due to its short battery life and relative cost. Giving it enchantments would bring it up to its tier, but would also completely unbalance the set.
A better solution is to give the E-coal armor some upgrades which can be installed to make it more effective:
Capacitance: E-Coal armor has a higher internal storage
Battery: Acts like a battery in your inventory, only inside the armor
Flashlight: Turns on when dark. Can be configured to be always on or toggle
HV-Receiver: Allows the armor to recharge by standing in a power dish's path
Bio-Sensor: Emits a wireless signal based on your character's health or food
Inventory Monitor: Emits a wireless signal based on your inventory space: uses comparator output
Power Monitor: Emits a wireless signal based on the % of energy left in the armor
Locator: Emits a wireless signal based on your X/Y/Z co-ordinates. Scale can be configured (10V =10k blocks)
E-Choke: Allows the armor to be less effective but also use less energy
E-Boost: Armor deflects all damage at a greater cost of energy
ESD Module: When taking a hit, unleash a burst of electricity at whatever hit you
Some of these upgrades could even be installed into tools as well, if their effects are relevant.
The E-Coal armor in its current state isn't really worth using due to its short battery life and relative cost. Giving it enchantments would bring it up to its tier, but would also completely unbalance the set.
A better solution is to give the E-coal armor some upgrades which can be installed to make it more effective:
Some of these upgrades could even be installed into tools as well, if their effects are relevant.