Batteries won't boil at 13.2 volts. Your T-105s should take 2 full amps and not have a problem.

Go to the Trojan website. There's a lot of info. there.

When was the last time you did a hydrometer test of each cell in your battery bank? If the battery's are charged, let them sit for a while without the charge on and test each cell with the hydrometer (less than 10 dollars anywhere). You may get your answer.