Identify Battery Issue with 18V DeWalt Tools

What happens here

The creator introduces a common problem experienced with older DeWalt 18V tools: their NiCad batteries often fail to hold a charge or become unusable, even if the tool itself is still functional. He demonstrates this by attempting to activate an 18V DeWalt drill with an installed 18V NiCad battery, which produces no power, highlighting the issue that many users face with outdated battery technology.

Goal: Understand the problem with old 18V NiCad batteries.