01 Passat no electrical at all

The other morning I went to start my 01 Passat and I am getting zero electric through the car, no dashlights, radio, clock, etc. I am thinking that it is either the battery, because it is old and has had some terrible corrosion on it lately, or the alternator, because at idle my motor repeatedly drops like it is going to stall. One strange thing was that yesterday I went out to look at it and the electrics were all on again, I could use the remote to unlock, clock worked, etc., but as soon as I tried to start the car it completely died again.

FYI, a week or so ago, I had to cut and re-attach a new battery line because mine had almost corroded through. Everything has been fine up until now. I doublechecked the connection, but could it be a main fuse that has blown? Thank you for any help.

Have you cleaned your battery terminals and cable terminals ?
Have you had the battery tested ?
You said you had to cut and re-attach your battery cable.
Did you replace the entire cable or just the connector ?
If the cable was that bad in that area it might very well be completely bad.
Just some thoughts.

I have double-checked the terminals and connections and everything is clean. I also replaced the battery thinking it might fix the problem, but I still have no power. My next guess would be the alternator. I thought maybe the starter, but it's not turning over at all and I'm not hearing any click from the starter, and correct me if I'm wrong, but the starter isn't really directly related to electrical in the car is it? Would a problem with the alternator come up on the computer fault codes when hooked up and scanned?

I took all the connections apart and re-did everything and it fired right up, verrrry strange, but I did get to take the new $60 battery back that I bought, thanks for help.

Just in case someone else is having similar problems, my car stopped receiving any power again and after hooking up a mulitmeter throughout the lines and connections, I was able to conclude that the new terminal connection that I bought at Advanced Auto was restricting the flow, perhaps because of the powdercoating and red paint, but after changing up the connections it is fine, I hope this may help anyone else with similar issues