Battery OEM FORD or OEM Mercedes

Always read your manual/mfr suggestions for battery charging and longevity.

For Li-ion you generally should charge no more than 80% (some mfg hide 10% via software like Ford, so you charge to 90%). Also, limit fee cycling these types too, regularly you should DC to about 50% max. Occasionally deep cycling and full charging is fine. Should limit DCFC also.

When you say, \u201ctwo new batteries\u201d are you speaking of the big ones? There is a small one that operate your convenience/comfort items. It looks like a small garage door battery.