Campervan Battery & FF Heater Guide in Japan | Roam and Roll Renter Tips
- roamandrollcampervan
- Mar 2
- 4 min read
Updated: Mar 12

If it’s your first time renting a campervan in Japan, it’s completely normal to have questions about the battery system and the FF heater. This guide explains how both systems work, how to use them safely, and what equipment is included in Roam and Roll campervans so you can travel confidently and avoid common mistakes.

Batteries: How the Dual Battery System Works
All Roam and Roll campervans use a dual battery system, meaning there are two separate batteries onboard:
Engine battery: Used only for starting the vehicle
House (sub) battery: Powers interior equipment such as interior lights, charging ports, the fridge (if equipped), and the FF heater.
The battery is 1,000w, 100AH lithium-ion battery system. It can charge approximate 50 iPhone 15/16.
The key benefit of a dual battery setup is that normal use of interior equipment is designed around the house battery, helping protect the engine battery needed to start the van.
Battery charging (important for trip planning)
The house battery charges automatically while you drive. As a general guideline, driving around 2–3 hours per day helps keep power levels healthy for typical campervan use.
Battery tips (best practices)
If you plan to stay parked in one place for a long time (more than 3 days) and you have a lot of devices, do schedule occasional driving (2-3 hours) to recharge the house battery.
If your campsite offers an external power hookup (RV/Auto-camp), charging may be possible depending on location and setup, but it’s not required for normal day-to-day travel. Make sure you plan and book the RV parks in advance.
Please connect only electronic devices with a power consumption of less than 1000W.

FF Heater: What It Is and How to Use It Safely
The FF heater (parking heater) is designed to keep the cabin warm without running the engine, making it ideal for cooler nights, mountain areas, and shoulder seasons.
How the FF heater works
The FF heater uses fuel from the vehicle’s main fuel tank. It consumes very small amount of fuel for a full night of warm.
It also uses a small amount of power from the house battery to start and run efficiently.
FF heater tips (safe operation)
Use the heater only while the vehicle is parked and stationary.
Make sure the heater’s external vents and airflow areas are not blocked by luggage, leaves, snow, or debris.
When using the heater, make sure to open the campervan's window slightly for ventilation.
Avoid using the heater at very high elevations (more than 1,500m above sea level).
For overnight heating, it’s best to drive a bit beforehand so the house battery is well charged.

Quick Summary
Roam and Roll campervans have a dual battery system engine battery for starting the van, and a house battery for interior power. The house battery recharges while driving, so regular driving helps maintain power. The FF heater runs on fuel and uses a small amount of battery power, and it’s safe and comfortable when used correctly with proper airflow and battery management.

What’s Included in Roam and Roll Campervans (Equipment Checklist)
To make your trip simple, our campervans are equipped with key travel essentials. In general, rentals include:
Sleeping Essentials
Bedding set (pillows + blankets)
Cooking Setup
Gas stove
Gas canisters
Cooking utensils / basic kitchen equipment (for everyday cooking)
Microwave (Poka mini only)
Outdoor Camping Gear
Camping table
Camping chairs
Note: Included equipment may vary slightly by model. If you want the exact checklist for your specific vehicle (SOYO / MORI / NAMI), tell us your booking model and dates and we’ll confirm the included items.
Note 2: Poka mini campervan does not have cooking setup and camping gear. These equipments can be added for additional fee.

Common Questions (FAQ)
1) Will I run out of battery if I camp without driving?
If you stay parked for long periods (more than 3 days), battery levels can drop depending on usage. Plan short drives to recharge, especially if you’ll use the heater at night.
2) Do I need an RV park power hookup?
Not necessarily. For most trips, driving regularly is enough. Hookups are a bonus when available.
3) How long can the batter last?
With regular light usage and charging of devices, it may consume 10-15% a night. The battery can charges approximately 50 iPhone15/16.
4) Does the FF heater drain the fuel tank quickly?
The heater uses fuel from the main tank, but consumption is generally modest. Make sure you have at least a quarter tank of fuel in the campervan.
5) Can I use the heater all night?
Yes, it’s designed for overnight use when parked. Make sure the house battery is sufficiently charged, vents are not blocked and open the window of the campervan slightly for ventilation.
Planning a campervan trip in Japan and want to feel 100% confident with the batteries and FF heater? Message Roam and Roll Campervan Japan with your travel dates and destination area, and we’ll recommend the best usage tips for your route and season.























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