Balance Catamarans Provide A Layman’s Terms Explanation of New Technology
What is integrel?
Integrel is a highly customized version of an alternator combined with an intelligent power controller. Let’s call it an “engine mounted generator”. It uses the “spare power” made by the engine to charge the Lithium house battery bank. What makes the Integrel different is the fact that it operates very efficiently at 48 volts and is controlled by a sophisticated power management system and a network of redundant safety checks and balances. For those reasons, it can safely and more efficiently produce up to 10x more power, and therefore a faster charge, compared to a conventional alternator.
How Does It Work?
The Integrel system consists of many sophisticated components and innovative technologies. To describe them all would require the reader to have a comprehensive understanding of marine electrical systems. Therefore, the following explanation is a simplified breakdown of the major components and operations.
The Integrel components that are mounted on the engine itself look very similar to a standard large-frame alternator. They include the engine-mounted DC generator, robust crankshaft mounted pulley, tensioners, and a specifically sized serpentine belt. Power is created by the DC generator which is turned by the serpentine belt on the crankshaft pulley.
The Integrel DC generator can create between 3kW and 8kW of power depending on operating conditions. The operating conditions are dependent on the RPM of the engine and the “spare power” available at any given point in the engine’s power curve. The Integrel is kept at optimal efficiency without overloading the engine by the innovative Integrel Charge Controller. The Integrel Charge Controller regulates how much power is being received from the DC generator and how much load is being put on the engine. The Controller “speaks” in a digital language to all components of the system, including the engines and batteries, to determine power needs and optimal operating parameters.
The power passes through the Charge Controller and is then sent to a DC Distributor which routes it to the various components of the system. Most of the power is going directly into the 48 volt Lithium battery bank after passing through another stage of power management and safety checks. Since very few of the boat’s systems operate at 48 volts, the power must be stepped down to both 24 volts (for operating boat systems such as air conditioning units) or 12 volts (for systems such as the VHF radio). This is accomplished through the use of specifically designed stepdown battery-to-battery chargers/converters and the addition of 24 volt and 12 volt buffer batteries.
The 48 volt battery bank is also connected to the 5000w Inverter/Charger which converts the power to AC and supplies 110 volt power to all electrical sockets and small appliances onboard.
Finally, all electrical systems on the yacht will operate off the inverter or directly off their respective batteries. This allows the Integrel System to include Multi-Voltage Charging capability which means that the boat can be plugged into both 110v or 220v shore power sources. The shore power source will charge the house battery bank and, since all systems run off the batteries, it will not have any effect on how the boat’s systems can be used while plugged in.
What Are My Options?
Integrel Solutions have been working very hard to design the best possible system specific to all our various catamaran models. We have several “Electrical Option Packages” that include greater capabilities based on how each client intends to use their boat. These will be comprised of two different Integrel setups and three different solar arrays to complement them. All packages also include a standard 20kWh (416ah @ 48V with 200ah @ 24v buffer) lithium-ion house battery bank.
Why a 48V battery bank?
48V is more efficient. The lower the voltage you have the larger the cable you need to carry the power around your boat. For example, a 12V appliance needs a cable that is roughly 4 times larger than what you need for 48V. More weight, more cost. The industry recognizes this, so you see a slow shift to 24V and then on to 48V. Today, many high-energy consumers like Air Conditioners, Water Makers, Winches, Bow thrusters, and even Windlasses are offered in 48V.
Single Integrel Option
The Single Integrel Option has the DC generator mount on only one of the boat’s engines. It will allow you to charge at 3kW at idle or up to 8kW under load. It will be more suited to clients who are weekend sailing, near-coastal cruising, or island hopping.
- Cheaper (than conventional generator configuration or Dual Integrel)
- Simpler Installation
- Less Equipment to maintain / service
- Slightly less weight than a Dual Integrel
- Slower Charging
- Lacks Redundancy
- Reliance on one engine (difficult to keep engine hours even)
Dual Integrel Option
The Dual Integrel Option has a DC generator mounted on both of the boat’s engines. Your charging capabilities will be effectively doubled, allowing for 6kW at idle or up to 16kW under load. This setup will be best suited for full-time cruisers and clients who intend to make frequent offshore passages.
- Significant power creation
- Faster charging
- Ability to switch between engines for charging
- More complicated installation compared to Single Integrel
- More maintenance (although limited and less than a conventional generator)
- More Expensive
Example Solar Config Options
Package – 440w total
- 2 x 220watt Panels and one regulator.
This package is the base spec for the boat and includes two solar panels mounted aft on top of the hardtop bimini. This setup is appropriate for owners who will be sailing their boats on the weekends or only using the boat for short-term coastal cruising. It is not recommended for a full-time liveaboard.
Package – 800w total
- 2 x 400w Panels and one regulator.
This package includes larger panels in place of the base spec equipment, also located aft on top of the hardtop bimini. This setup is designed for cruisers who intend to spend most of their time cruising the islands with occasional offshore passages.
Package – 1600w total
- 4 x 400w Panels and two regulators
This package includes the large panels mounted in two banks on the hardtop bimini and each bank is wired to its own regulator for added efficiency. This setup is designed for cruisers who intend to cross oceans and spend a lot of time offshore.
Option to add an additional 400w panel – a total of 2000w.
What Are Some Other Considerations?
Cost: At first glance, Integrel is not a cheap option. But if you start adding up the cost of the comparable conventional Generator and our various Lithium Options then it actually starts to look cheap. The Single Integrel Option comes in under the price of a fully optioned Lithium and Generator boat; while the Dual Integrel comes in slightly higher priced. Taking into account the added battery capacity and capability of Integrel, it is actually a much better “bang for your buck”.
Weight: The net weight savings of the Dual Integrel Option compared to the conventional Generator setup will be approximately 400lbs. That is a significant weight reduction for a performance-oriented sailboat. It also has the advantage of opening up the physical location of the generator compartment for other equipment or more storage space.
Maintenance: A conventional generator requires regular oil changes, impellor replacement, belt-tightening, etc. Diesel fuel and regular maintenance. All the requirements of any marine diesel engine. This means that you must carry parts and spares for a third marine diesel. Integrel is very low maintenance and will only require the infrequent replacement of the serpentine belt.
Functionality: A conventional generator requires a hands-on approach to maintaining a battery state of charge. You must always keep an eye on your power consumption and house bank discharge. When you reach a certain point, usually 30% on lithium banks, you must start the generator and run it to recharge. Our standard generator option is a Northern Lights 5.5kW model. When running it strictly to charge the battery bank it will not be under full load and will therefore be running inefficiently. This means that battery recharge times can take up to 2 or 3 hours. Compare this to the shorter, more powerful charge cycle of Integrel and the added benefit of charging while motoring, it is a much more efficient means of recharging your battery bank. In the event that the discharge of house batteries gets too low, the Integrel system will sound an audible warning that will prompt the user to run an engine for recharge purposes. For this reason, you do not have to spend nearly as much time worrying about the battery state of charge.
User-interface: The Integrel has a whole host of additional features that coordinate with an electronically controlled engine to give the user more information and functionality. This information is presented on the Integrel display screen located next to your battery monitor screen in the starboard hallway. They include:
- Tracking fuel consumption
- Redundant fuel level monitoring
- Fuel efficiently data
- Ability to adjust system parameters in Real-time
- Precise battery state-of-charge data
- “Time-to-Go” for the current rate of discharge
- Data Log that will save several GB of past performance data
Safety: The Integrel has built-in safety features to ensure proper operation and to prevent the user from damaging the system.
- “Limp Home” Mode – Allows system minimum operation in a fault scenario
- Automatic Fault-Finding System – Notifies user about specific faults
- Data Log – Saves past fault data which can be uploaded and shared
- Active Temperature Sensors – Responds as temperatures rise prior to a fault
- Active Current Measurement – Very accurately measures power into batteries
How Will I Use It?
The reality of Integrel operation is that you will not often have to run the engines strictly to charge your house battery bank. Consider a few hypothetical scenarios:
At Anchor – You are in the Virgin Islands with 4 people aboard and moving from one anchorage to the next. You are sailing during the day and finding a serene anchorage every night. You’re using all the usual boat systems to make for a comfortable liveaboard experience i.e. lights, electric toilets, charging phones and computers, running the water maker, and using air conditioning at night. Every morning you wake up and your lithium battery is at a 60% state-of-charge after running two 10BTU A/C units all night. After breakfast, you pick up your hook and head out of the anchorage for your next destination. With Dual Integrel, you will have recharged your house batteries by the time you’ve motored out of the anchorage and raised your sails (+/- 30 minutes). In conjunction with an appropriate amount of solar charging, you will rarely be operating the engine strictly for the purpose of recharging the batteries.
Offshore Passage – You are sailing offshore on a long delivery across the Pacific. You have favorable weather and no need to run the engines for propulsion. You are using the usual systems for a long offshore passage i.e. autohelm, chart plotter, water maker, electric cooktop, etc. There is a significant discharge on the battery bank every day. In this scenario, you will occasionally have to run the engines specifically to recharge the batteries. The amount of time necessary for this will be dependent on the amount of charge you are receiving from other sources such as solar panels and the amount of discharge from sources like the power-hungry water maker. Due to the fast charging capabilities of the Integrel System, even with a nearly depleted battery bank, they will be brought back up to full charge very quickly and will only require the engines to be run for short periods of time for strictly charging purposes. With dual Integrel at idle speed and the engines in neutral, the batteries will be charging at 6kW. If you decide to motor sail at 2400rpm on both engines, you will be charging around 14kW. In this scenario, you will have the fully depleted batteries (30% state-of-charge audible warning) topped off in +/- 1 hour.
As A Generator – You are in the rare scenario in which you are at anchor, no wind, very hot and humid, and it’s raining. You have guests on board and need to run all of your air conditioning at night to keep everyone happy. Doing this will deplete the house battery bank before morning. In this situation, you can turn on one of the engines and have the Integrel act as your generator. Let the engine run at idle which will offer charging at about 3kW. The Integrel will counterbalance the draw from the A/C and allow you to sleep through the night without worrying about the discharge of the battery bank. An engine running at idle speed will barely be perceptible by the guests sleeping inside the boat; just a low hum and a slight vibration. This will be an infrequent “worst-case scenario” for how you will use the Integrel in real-world conditions.
At Integrel, we feel that the advantages of this new technology make it worthwhile for us to be the first production builder to be an early adopter. The increased charging capabilities, simplified operation, robust design, and reduced weight are all factors that fit perfectly with our desire to offer the greatest balance of lifestyle and functionality on a performance-oriented catamaran. We also believe this technology will be a significant step on the path to advance marine technology into a more sustainable future.
- Q: If I get a single Integrel system and it goes out, can the other engine generate current to the batteries?
A: The Integrel incorporates 48v components and a 48v battery bank which cannot be charged by a conventional 12v / 24v alternator. Therefore, we suggest you have at least 1,000 watts of solar in the event there are technical issues with a Single Integrel. This will give you a sufficient power supply to manage the boat back to a port for repair or replacement. This isn’t any different than a generator going down, other than that most generator boats have one or two 24 volt alternators.
- Q: Why do I need 12v and 24v buffer batteries?
A: The Integrel requires buffer batteries because many marine systems operate on 12v or 24v. Since our house battery bank is 48v for increased efficiency, we must incorporate a way to provide power to these lower voltage systems. The marine industry is working hard on the transition to a higher voltage and many companies are developing systems that operate on 48v. As more products become available, we will incorporate them into future packages. Eventually, we may get to a point where we can eliminate the 12v and possibly even the 24v systems altogether.
- Q: Does the system add significant wear and tear to the engine?
A: NO. Integrel have done extensive laboratory tests running the system for 1000 hours, then stripping the engine and sending the crankshaft and bearings away for independent analysis at Rolls Royce labs. The conclusion was that the integrel system produced no measurable additional wear to the engine. Diesel engines are designed to run under load. So there is more damage done to the engine in scenarios where the engines are run for hours at slightly above idle using a normal alternator to charge a 12 or 24v house bank. Conclusion integrel causes less wear and tear than in this scenario.
- Q: Does the system affect the engine service warranty?
A: Integrel provides World Wide Insurance to cover any claim for engine damage, with far fewer “exclusions” than a normal engine warranty.
- Q: Are there added safety considerations with a 48v system? Electrocution? Fire?
A: Integrel has meticulously provided additional layers of safety around the management of lithium-Ion batteries. Enabling the use of induction cookers removes the risk of propane fire that is the most common cause of the fire on a yacht
- Q: What is included in the Integrel System warranty?
A: The integrel system comes with a 2 year, worldwide replacement warranty