This article details a comprehensive off-grid power system for a boat, focusing on the implementation of dual lithium battery banks. The author meticulously outlines their setup, which includes two high-capacity lithium battery banks – a primary system and a robust backup – integrated with a substantial solar array for charging. This detailed review explores not only the components involved, but also the safety measures implemented, highlighting the importance of proper fusing and the use of reliable monitoring equipment. The system's design prioritizes redundancy and resilience, addressing potential challenges faced by boaters relying on off-grid power.Beyond the primary and secondary lithium battery banks, the system incorporates a portable power station for smaller appliances, further expanding its capabilities. The author offers a practical guide to building a reliable and safe off-grid power solution for extended boating trips, regardless of weather conditions or access to shore power. This detailed account provides valuable insights into component selection, installation techniques, and the overall considerations involved in creating a robust and dependable power system for extended off-grid adventures.
Pros And Cons
- Nice package with Xantrex batteries
- High quality
- Very high quality
- Metal cases, nicely designed
- Easy to install
- Built-in 250 amp class T fuse
- Expensive ($1800 each)
- Useful for charging phones and cameras
- Powerful inverter for portable use
- Can heat water for off-grid showers
Read more: OUKITEL P2001 PLUS Review: Best Budget Portable Power Station?
Primary Lithium Battery Bank System
My primary battery bank resides under a cabinet in the boat's v-berth area. This system uses two Xantrex 240 amp-hour lithium batteries, renowned for their high quality but premium price tag. They're securely mounted to a wooden plate, ensuring stability during transit.
These batteries are connected to an Xantrex 2000-watt marine inverter (FreedomX Pro), providing a reliable power solution. The system is paralleled to a bus bar, and then wired to the inverter, which has its own shut-off switch for safety. This setup ensures seamless power distribution for my onboard needs.
Solar power integration is a key feature. A 60-amp breaker manages two solar controllers feeding approximately 1000 watts of solar power. This consists of a 600-watt system on the flybridge and a 400-watt portable panel deployed while at anchor. This setup yields roughly 500-700 watts of solar power on a sunny day, even considering the boat's movement at anchor.
Fusing and Safety Precautions
Safety is paramount, and this system utilizes Class T fuses within the batteries themselves, capable of handling up to 20,000 amps. These fuses offer superior protection compared to other fuse types, preventing arcing and potential hazards associated with high-energy lithium batteries.
In addition to the internal fuses, 150-amp terminal fuses are added for extra protection. This setup ensures that if a fault occurs, the less expensive terminal fuses will blow first, safeguarding the more costly internal fuses. A 300-amp fuse protects the inverter's wiring.
All cabling is 2-watt marine-grade tinned cable with a 105 Celsius temperature rating. A battery monitor provides real-time voltage, current draw, and capacity information, offering a reliable visual check independent of the potentially inaccurate app readings.
Backup Lithium Battery Bank
The backup battery bank, located in a large box in the engine bay, previously housed four golf cart batteries. It has been upgraded to a single 460 amp-hour lithium battery. This large battery is securely mounted using wood supports to prevent shifting.
This backup bank is equipped with its own battery monitor, allowing for easy monitoring of its performance. The system uses a 300-amp Class T fuse and a 300-amp terminal fuse for protection, and is wired to the main DC panel via a switch, enabling quick switching between the primary and backup banks.
A dedicated 200-watt solar panel charges the backup bank independently. This ensures the backup bank maintains a charge, even when the main bank is in use.
Solar Panel Setup and Deployment
The solar panel setup includes two 100-watt panels on the flybridge and two 200-watt panels mounted on the bimini. These panels are adjustable and can be secured even in windy conditions.
A 400-watt Renogy portable panel is deployed using kayak holders and custom brackets. This panel is secured using bungees to protect it from high winds while at anchor or underway.
A 200-watt portable panel is also used to top up the backup battery bank. This panel is laid out on the bow and is secured using bungees.
Blueetti Portable Power Station and Additional Components
A Blueetti Elite 100 portable power station provides additional power for smaller devices, such as phones and cameras. It also has a powerful inverter for tasks such as heating water for showers.
This power station can be charged via a DC-DC charger while underway, or by drawing power from the main inverter. This versatility ensures that even during longer trips or in areas with limited sunlight, power is available.
Various apps monitor the systems, including the batteries, solar controllers, and inverter. While app data can be inconsistent, dedicated external battery monitors provide a reliable visual check of key metrics.
Conclusion: Is This System Worth It?
This dual lithium battery bank system, complemented by an extensive solar setup and portable power station, offers exceptional off-grid capabilities. The substantial capacity ensures ample power even during extended periods of low sunlight or inclement weather.
While the initial investment in high-quality lithium batteries and other components is significant, the reliability, long-term benefits, and freedom from reliance on shore power make it a worthwhile investment for boaters who prioritize off-grid adventures.
The combination of high-capacity lithium batteries, multiple solar panels, and a backup system provides peace of mind for extended boating trips, particularly in regions with unpredictable weather conditions. The added safety features and monitoring capabilities further enhance the overall value proposition.