RV Alternator Charging Time Calculator
Find out exactly how much driving time is needed to top off your house batteries.
Charging Estimator
How empty are your batteries?
Check your vehicle manual (typically 100A-220A).
Enter 0 if you don't have a DC-DC charger (Direct connection).
Charging While Driving
Using your vehicle's alternator to charge house batteries is a great way to replenish power while moving between campsites. However, it's not as simple as just connecting wires.
Why You Need a DC-DC Charger
Smart alternators in modern vehicles often lower voltage to save fuel, which can stop charging your house batteries. Additionally, lithium batteries can pull so much current that they overheat and damage a standard alternator. A DC-DC Charger solves both problems by regulating the charge profile and limiting current.
Protecting Your Alternator
Alternators are designed to top off a starter battery, not run at full power for hours to charge a large battery bank. Running an alternator at 100% duty cycle while idling can cause it to fail prematurely.