MEXICOWANDERER wrote:
Jajajajajajajajajaja, my kind a post! saludos,
Trying to add water to 8-year old AGM is like giving a 107 year old man a heart liver transplant.
They are almost 10 years old, according to the OP. It's miracle they still work - though possible with shallow cycles and daily 100% charging.
Since this is Concorde, I'd try their "conditioning procedure", see the Manual. The only manufacturer that tells how and when to condition the AGM, as if other AGMs were so perfect that didn't need that.
Consider that the solar panel is at least 10% less efficient after 10 years, so with any battery expect it to charge slower now.