Medkits are pretty self-explanatory, healing any units within the yellow ring that they deploy once you fire them onto the battlefield. Remember, Medkits only affect units currently inside their radius, so you need to target them so that the troops you want to heal are stationary inside their radius. You also can use multiple medkits to 'stack' their effects.
First Shot: 6 Energy
Second Shot: 9 Energy
Third Shot: 12 Energy
Fourth Shot: 15 Energy
Medkits are very straightforward to use. Throw them at an injured ally and they will be healed. All Medkits last the same amount of time (7 seconds), regardless of what level they are at. When you upgrade them, their strength increases, but otherwise they remain the same.
The best position for a Medkit is always a location that you know your troops will remain still at. Throw them near buildings so that they are healed while they attack - if your units are moving then there's a chance you will have wasted your power-up.
Healing per pulse: 7
Total Healing: 175
Research Cost: None
Armory Level Required: None
Research Time: None
Healing per pulse: 8
Total Healing: 200
Research Cost: 12,100
Armory Level Required: 1
Research Time: 3 hours
Healing per pulse: 9
Total Healing: 225
Research Cost: 23,800
Armory Level Required: 2
Research Time: 4 hours
Healing per pulse: 10
Total Healing: 250
Research Cost: 50,000
Armory Level Required: 3
Research Time: 7 hours
Healing per pulse: 11
Total Healing: 275
Research Cost: 99,000
Armory Level Required: 4
Research Time: 11 hours
Healing per pulse: 12
Total Healing: 300
Research Cost: 168,000
Armory Level Required: 5
Research Time: 15 hours
Healing per pulse: 13
Total Healing: 325
Research Cost: 284,000
Armory Level Required: 6
Research Time: 21 hours
Healing per pulse: 14
Total Healing: 350
Research Cost: 450,000
Armory Level Required: 7
Research Time: 1 day 4 hours
Healing per pulse: 15
Total Healing: 375
Research Cost: 650,000
Armory Level Required: 8
Research Time: 1 day 8 hours
Healing per pulse: 16
Total Healing: 400
Research Cost: 760,000
Armory Level Required: 9
Research Time: 1 day 8 hours
Healing per pulse: 17
Total Healing: 425
Research Cost: 850,000
Armory Level Required: 10
Research Time: 1 day 11 hours
Healing per pulse: 19
Total Healing: 475
Research Cost: 1,160,000
Armory Level Required: 11
Research Time: 1 day 20 hours
Healing per pulse: 21
Total Healing: 525
Research Cost: 1,590,000
Armory Level Required: 12
Research Time: 2 days 3 hours
Healing per pulse: 23
Total Healing: 575
Research Cost: 1,800,000
Armory Level Required: 13
Research Time: 2 days 3 hours
Healing per pulse: 25
Total Healing: 625
Research Cost: 2,160,000
Armory Level Required: 14
Research Time: 2 days 6 hours
Healing per pulse: 27
Total Healing: 675
Research Cost: 2,970,000
Armory Level Required: 15
Research Time: 2 days 22 hours
Healing per pulse: 29
Total Healing: 725
Research Cost: 3,400,000
Armory Level Required: 16
Research Time: 2 days 22 hours
Healing per pulse: 31
Total Healing: 775
Research Cost: 3,800,000
Armory Level Required: 17
Research Time: 3 days 7 hours
Healing per pulse: 34
Total Healing: 850
Research Cost: 4,500,000
Armory Level Required: 18
Research Time: 3 days 10 hours
Healing per pulse: 37
Total Healing: 925
Research Cost: 5,300,000
Armory Level Required: 19
Research Time: 3 days 14 hours