I see that the max. voltage for that charger is 18V.
I bought one from here for my NET3(250W) charger but I got the 24V version:
http://cgi.ebay.com/15V-DC-23-2A-350...item2559851f4a
You will need to add the connectors for the input power plug (240V) and the output plugs for the charger.
http://www.rcgroups.com/forums/showthread.php?t=1154748
The power supply doesn't get hot when I charge 2S at 20A.