How to prevent charging cars from battery

[power.saver]

If you set it to 100% will solar throttle because powerwalls are full.

Yes, and may shutdown completely if your inverters can't do Freq-Watt curtailment.

 

[jjrandorin]

If you set it to 100% will solar throttle because powerwalls are full.

This sort of sounds like a question, but is written like a statement (with a period). If its a question, the answer is " the setting in question will go no higher than 95%, at least on my system."