If your Power Core inventory goes over 6000, you reached the limit, so here’s what you need to know:
At the 6000 Power Core Limit:
Once you reach 6000 Power Cores, you will stop receiving duplicate Power Cores.
Instead of duplicates, you’ll receive Energon until your Power Core count drops below the 6000 threshold.
How to Start Receiving Power Cores Again:
To get back under the 6000 Power Core cap and start receiving them again, you’ll need to fuse some of your existing Power Cores.
Exception:
Duplicates from Combiner Bots are an exception to this rule. These duplicates will continue to reward you with Power Cores, even if you exceed the 6000 limit.