Battery Health & Charging Options

[SirDrake]

I'm looking for some advice on Battery Health and Charging.
I have read through numerous posts on this forum concerning the TM battery and charging and I have a couple ideas.
I guess what I am primarily looking for is the best way of charging the battery in my TM and keeping it in good health.
We don't do any boon docking, at least not yet, so we use the battery primarily for the refrigerator while traveling.
Most of our trips take 6 hours or less on the road, so running the fridge on battery is feasible.
Also, we camp at sites with full hookups and I like to keep the TM plugged into shore power when parked at home.
I usually pull the battery for winter and store it in the garage.

The TM came with a group 24 marine battery, which I upgraded to a Group 27 a few years ago.
I learned the hard way that the Converter/Charger in the TM, if left plugged into shore power, will cook the battery; I didn't realize that the on board charger was not intelligent.
Needless to say the Group 27 Lead/Acid battery is dead. So I decided to buy an Optima AGM Marine battery to replace the old lead/acid unit (no more fumes, liquid, etc).
I just bought a blue top Optima D34M and now I am trying to decide the best way to maintain it.
https://www.optimabatteries.com/en-u...-starting/d34m
I read through many, many threads concerning the TM battery. I like the idea of either upgrading the charger in the TM or adding a third party charger to the battery compartment.
The DC Charger that ShrimpBurrito installed sounds interesting too and I believe it was Bill (the moderator) who has a Guest charger in his battery compartment.

Here are my thoughts.
Option1:
I could upgrade the Parallax 7300 on board Converter with the new Ultra III kit.
Found a site that sells 45 and 55 amp kits ranging $198-$213.
http://www.bestconverter.com/Magnete...-Kit_c_64.html
This kit upgrades the charging unit to 3-stage charging capabilities.
Not sure if I need 45 or 55amp though, and would this work well with my Optima battery?
Can I leave the TM plugged into shore power and not toast the battery with this upgrade?
If I go this route, is there a monitoring device I can install to show the stats on the battery?
Anyone have any experience with this kit or similar on board converter/charger?

Option 2:
My other thought was to skip the on board upgrade and install a separate charger in the battery compartment.
Optima sells a portable performance charger, the Digital 400 for $110.
It is designed to work best with the Optima batteries, obviously, and seems to get 5 star reviews online.
https://www.optimabatteries.com/en-us/battery-charger
I was thinking that I could mount it in the battery compartment and run an extension cord to the power outlet behind the refrigerator to power it (when plugged into shore power).
In addition, I was going to install a Three-way Battery Switch in the compartment as well, so I could switch between:
1. Shore Power/TM Charger (for traveling purposes)
2. The Optima Charger (for when I have shore power)
3. Off (battery disconnect)
https://www.amazon.com/dp/B001V7TL10...84KLCX38&psc=1

If anyone has any input, thoughts, etc I would greatly appreciate it.
Thanks!

~ John