12.0V is not too low with a load on the batteries. 12.14V static is considered 50%, but any load on the batteries will cause the voltage to go lower. Magnum recommends setting it at 11.0V to prevent unnecessary starts. Do you have your AGS already? I have one to sell.
Scotty and Kristen, Airedales Dagny and Wyatt
2007 Newmar Mountain Aire 4528, 450 HP ISM, Allison 4000, 8 Lifeline AGM's
2019 F250 King Ranch 4x4 Powerstroke
Roadmaster Blackhawk 2, M&G 2.0 Proportional Brake System