What's an ION battery? Lithium Ion or is it a brand name?
"boosting chassis battery"?
From time to time your Ford battery goes dead so you start it with a boost from the house battery? Is that what you're saying?
To answer your question about Lithium Ion batteries they will function just as a flooded or AGM so your boost will work. However you need to find out if the converter has a stage to properly charge a Li-ion battery.