Spaceships don't come with two batteries, they come with a smart battery system. Thisis an intelligent system that makes sure the battery isn't drained when the engine isn't running. It makes sure there's always power left to start the engine the next morning.
The 12V smart battery system of your Spaceship allows you to run internal items, like the fridge and USB ports on the car battery. It protects the battery. It's like having a second car battery. The battery won't go flat. It's a closed system, with no plugs, and no connections for outside items or devices. It charges when you are driving and it powers the internal items when the engine isn't running.
You can use the fridge and use USB ports at night. No worries. The smart battery system will protect the battery so you can always start the engine again in the morning. As you'll be driving again the next morning the system will fully charge itself again so you can use it again the next evening/night.
The system is self-charging. As long as you drive on a regular basis you'll be fine. Being on a campsite at 6pm and spending the night (leaving the fridge etc on) and then driving the next morning at 9am is fine. That's what most customers do on a road trip. Staying on a campsite for several days, leaving it all on will drain the system. But even then, there will always be a little bit of power left to start the engine so you can drive and charge again. That's why it's called a smart battery system.
Self-contained campervans with a solar panel roof
The smart battery of our self-contained campervans will last even longer. However, it will all depend on where you park it and what the weather is like.
Tip: set the fridge on setting 2 to 3 for maximum use of the battery charge while keeping your food cool.