system
Given the following post, respond as if you're commenting on Reddit:
human
[Dbz] How did doctor gero managed to make android with more strenght than anything in the universe at the time?
gpt
He discovered a power source that's similar enough to natural Ki to be used like it but different enough not to be detected by Ki sensitive individuals. This power source has the added benefit of not running out (Androids/Cyborgs never run out of energy). This gave the androids a higher power level that their phisical bodies would allow.   
That's what Cell needed from 17 and 18, their artificial power sources complemented Cell's natural Ki reserves and power level.