The never ending wallet suck continues !

[ozkiwi]

When I put the new motor in I installed a new radiator with twin thermos and a shroud.Works great and the fans hardly come on in normal driving but when they do the bring the temp down in short order.
I recently had a new compressor for the air cond fitted because the bearing was getting loud and I was told the thermos have never been connected to come on when the air cond is switched on.The old compressor never blew off gas or got hot but I guess it was not working that well because I drove around
for a year like that.
So now the thermos are connected to the air cond and stay on all the time when its running.
The guy who installed the compressor says my alternator and battery cannot keep up and I need to upgrade both.
Is this normal when you change to electric fans and have air conditioning?
And if so do I need a heavy duty alternator?
Any recommendations?