If nothing else, AGM batteries. No watering and more power.Rather than investing more into lead acid, you should investigate going LiFePo4. Prices have come down to the point of being less than the cost for lead acid batteries.
I have a similar system and highly recommend them. Makes checking and refilling the cells a breeze.Not automated but I use the Trojan watering system on my T105s and find it very effective. Simple snap connection to the hoses running between the caps with inbuilt float valves. Takes less than 5 mins a month to check/top up 2 banks of 6 batteries.
Trojan Battery | Single-Point Battery Watering System
The Single-Point Watering Kit is designed to work with flooded deep-cycle batteries. It takes the guesswork out of properly watering flooded batteries.www.trojanbattery.com
two years ago I would have agreed, but not know. Replacement cost on my battery bank of L16’s was $2800. For $2400 I was able to install a larger LifePo4 bank. FLA has a 300 cycle life were LiFePo4 has a 3000 cycle life. The world changed in the last two years. Why pay more for less.FLA is still the best bang for your buck. I use the "Water-your-Battery" system. It's not automatic but simple to install and very quick and easy to water your batteries in minutes from a gallon jug of distilled water without even removing the battery box covers. Be sure to order the correct caps for the batteries you use so that the fill levels are correct.
The only place I use AGM (which are considerably more expensive) is for locations within sleeping cabins (i.e. bow thruster bank)
That’s what I have been using for years. Works great and can save your batteries.Check out, Flow-rite battery watering systems
Auto-fill may sound like a way to avoid doing a maintenance item, but it is a poor choice.Looking for some guidance in setting up an auto fill for my house bank. I did a search in this forum but didn't see anything.
Any help is appreciated.