From my experience and I have the AGM battery in mine (2.0TDI), it charges the battery just fine. When the battery is discharged the voltage goes well over 14V even on V6 Amarok and as the battery is close to fully charged the voltage drops. When you see the 13.8V, it’s float charge and sure enough even for the AGM batteries. You don’t want them to be charged at 14.4V at high temperature environment, like under the bonnet. As far as charging a second battery away from under the bonnet, when you use DC-DC charger it will charge even when your battery is at any voltage from approximately 11V.
Bookmarks