Only a little. The charge wire in most 7-pin connectors is small, so it trickles power to your trailer rather than recharging it. And a lithium battery should only connect to an alternator whose output tops out at 14.6V or below. A DC-to-DC charger is the usual fix: it takes power from your tow vehicle and charges the trailer battery at the right voltage. Millertech carries 12V 10A (1210DC-DC) and 12V 20A (1220DC-DC) DC-to-DC chargers.

Your furnace burns propane, but its blower fan and controls run on your battery, and on cold nights that fan runs a lot. A lithium battery delivers steady power all night and doesn’t sag as it drains the way lead-acid does. Watch your remaining charge in the Millertech app so you know where you stand by morning.

Check with your RV manufacturer, since each one sets its own rules about electrical changes. Your Millertech battery has its own coverage: every Sport Series battery carries a 10-year warranty, and we pay shipping both ways. (Warranty page)