Answer: The main difference is that while primary cells cannot be charged, secondary cells can be recharged.
Step-by-step explanation:
A primary cell is an electrochemical that can't be recharged. The chemicals will be replaced regularly e.g. Leclanche cell.
The reactions in a secondary cell can be reversed through an external electrical energy source, heve, they can be recharged. Examples of secondary cells include nickel and lead storage battery.
The main difference is that while primary cells cannot be charged, secondary cells can be recharged.