[Target70]

I admit that we don't know what voltage and current the phantom battery charger is using. I don't even know if it has a circuit to stop charging when the batteries are full. So if the voltage is so high it will overload the AGM, and the current is so high it will overload the lead acid, the only thing I can think is to add a voltage limiting circuit on the charging side of the controller. Honestly the best thing to do would be to measure the phantoms charger circuit output.