Merging a Xantrex SW2024 to a Tesla Lithium battery

We have considered some sort of resistor setup to keep the voltage down but aren’t real clear on how to do it. You can set the voltage for absorption, but the bulk voltage does not stop at absorption level and switch to absorption. It keeps right on going up. We don’t know how far it will go because we don’t want to fry our battery. But our understanding is that you should limit the charging voltage of the Tesla battery at 25.2.