I ended up using a brand I have used in other equipment & RV's.
Motobatt. MBTX30U
I have had great service with their batteries before.
Their batteries also have 4 terminals so it is easy if you need to tap in without overloading the terminals that is a plus also.
They are only rated at 385CCA, but it tests out higher than that.
With all AGM batteries I never charge over 10 amp. Slower the better.
My OEM lasted 4.5 yrs.

 

Got the trike back today from the dealer. Had a new reverse motor installed and it feels much stronger than when the trike was new.

 

I've got a '16 with 12,000 miles. I use the reverse every day when I back into my garage. Always get the engine RPM's to 2000 when using the reverse. Haven't had any issues, works like a charm. By the way, I always have it on a battery tender.

 

I’m having the slow reverse issue now. When starting the engine, first couple of cranks are slow. My original battery is five years old now. Maintained with a battery tender, but I think it’s time for a new battery.

 

Our Tri-Glide is still doing fine on the original battery , it’s a 2017 and is on the tender except for the trip I know it’s time to replace battery