I caught the miscommunication BFL. He meant charging no issues, separated (isolated) same thing no issues. The parallel was stopped.
Unless finish charging voltages are different or amperage tolerances are limited, who cares? Certainly not the batteries.
A note too often ommited, is the engine battery suffers extremely high temperatures. Even at 13.4 volts temperature correct for the proper voltage at 125 degrees F and your eyes will open wide.
I hate to think what my bus batteries went through when it got to 122F at Ciudad Obregon, Mex.
You're still on Vancouver Island, right? Battery Paradise.
