Probably twice as long as the battery it replaced (assuming twice the range). You can still stop and recharge every 300 miles if you want to. Ultimately you're

Probably twice as long as the battery it replaced (assuming twice the range). You can still stop and recharge every 300 miles if you want to. Ultimately you're gonna spend the same amount of time charging to get the same distance. This just means you could go out 300 miles and back without stopping for a charge at all. The advantage of this though is that you can at least start with 600 miles of range from your home. You'd probably only ever have to charge it overnight, because that's a solid 12 hours of driving. So long as your hotel has a charger you can use, you're basically never stopping to fuel up on a road trip as a single driver.