18 volt xtreme cordless drill chargers?

It's an Argos Brand - Challenge Extreme - Einhell (made by Einhell) - spares perhaps from...

http://www.einhelltools.co.uk/cmspage.php?page_id=46
0151 649 1500

Or from Argos Customer Services

Or from e-bay

Or from Solent Tools - try here first 023 8057 8057

Are you sure it's both chargers that are broken rather than the batteries?

Good luck...
January 2015