Ok that's a 2 stage timed (I am not familure with the 7400 but I am the specs for the7300T and you just typed how it works)
You should be able to just plug it in and leave it on.. Forever.
I had a Progressive Dynamics Wizard.. It works a bit different. It monitors voltage and current.. Batteries low (Below around 90% it goes into BULK or as they call it BOST 14.4 up to .. mine was 80 amps.
Then it dropped to 13.6 to finish the charge
And 13.2 float.
Then after so many hours it would pop back to 14.4 for 15 minutes just to stir things up.
Batteries lasted 9 years plugged in well over 90% of the time (And engine running 90 percent of the rest at least) only time they were not charging.. was if Boondocking, wal-docking or parked at a truck stop having a meal or overnight.
Very pleased with it.. Sadly it only lasted 12.5 years then I had to get a rebuilt.. Thankfully the factory was right close to my "Beaten path" so I dropped in.. They don't do a lot of walk in traffic there :)