I think I am are confused. If you have a 12V battery bank, and 12V batteries, they will have to be wired in parallel, not series. Will's drawing shows them in parallel, pluses together and minuses together. That will increase the Ah, not the volts.
Because lithium batteries have low internal resistance, they can generally take all of the current given to them. So they could potentially cause your alternator to run at full speed for hours, which it is not designed to do. It is recommended that you run the alternator no more than 50% to prevent burning it out. The BattleBorn batteries are rated for up to 100A each, if you have 3 in parallel, that would be 300A max (solar plus alternator). For longer life, it is generally recommended you do a slower charge. With all of this said, you should plan on no more than 90A from your alternator.
If your alternator has an external controller with a temperature sensor, you can set the current limit to 90A and make sure the temp sensor is working and will throttle it back if it gets too hot. If it doesn't have an external controller, you can get DC/DC converters to do it. Victron makes an excellent 30A one, the Orion, you can wire 3 of them in parallel for 90A.