Lagoon 460 Power Upgrade without disturbing Factory Integrated Power System
To most people this will seem like a simple power upgrade with an overlay 48V system. However, it is one of the most complex scenarios of ensuring the 12V house lithium has priority charging and driving the factory alternators at a very precise voltage to extract a total of 3000W DC DC charging. We could not have done this before with Scotty V1 and the Wakespeed units without disturbing the alternators or the factory system. But now we can deliver a perfect result. The secret is the Scotty 1500 AI units. They can wait for the 12V Lithium to get to 95% SOC and then pull full power out of the alternators without taking anything from the 12V lithium, to charge the 48V Lithium Then when the engines are off, the Scotty’s are pouring up to 3000W from the 48V side to the 12V loads and/or 12V Lithium. A great way to add significant replenishment power without disturbing the factory system. #howgoodsthat #traveltheworld #withoutconsumingtheearth #havefundoingit #48V #victronenergy #dcdc #lagoon #lagoon460 #catamaran
Story behind this Video
Application: sailing, catamaran, Lagoon, Lagoon 460
Tags: Scotty, AI, lagoon 460, catamaran, sailing
Note the boat owner did not want a video of inside the boat or the name of the boat exposed for privacy reasons. This took some creative thinking to get a video of the story.
What is the Problem(s) to be Solved?
1) When this brand-new Lagoon was delivered from the factory to Australia, it had 5 x 100 Ah of 12V lithium batteries installed. This just wasn’t enough power to operate without a genset for silent operation:
· The electrical control system is a single integrated system; which we did not want to disturb in any way.
· The entire catamaran was wired on 12V with up to 3,000W of loads if two electric winches were operated at once.
2) The alternators on either Yanmar engine were factory supplied 120A each. At 14V this is over 1600W of power each but the Lagoon factory charging system could only extract 600W a side at 50%+ SOC%. This is a very low replenishment rate while motoring.
3) When Scotty 1500 AI was first connected to the 12V active circuit with the alternators, the 12V Lithium house bank is pulled down at a rate of 720W. This would be a deal breaker as the Lagoon is so dependent on 12V power all the time.
· The customer wanted significant replenishment power with solar and alternators to avoid using a genset but not disturbing in anyway the captured energy in the 12V house lithium.
· This was one of the more interesting projects tackled so far. It is very complex to solve given the requirement of no disturbance of the Lagoon’s integrated power system. My conclusion was it could only really be done with software… and Scotty AI has a powerful stack… so let’s see if it could do it.
How are these Problems Solved?
1) On the new aft stainless steel arch, 4 x 400W solar was installed. All in parallel at 76Voc to charge the 48V house bank.
2) 14,400 Wh of 48V Lithium House was installed.
3) Victron Quattro II 48/5000 as the inverter/charger
4) 2 x Scotty AI 1500 with one per engine installed charging the 48V Lithium House. When not charging, these are bi-directional and were set at 13.5V feeding the 12V house bank from the 48V house bank.
· The Scotty AI’s were set to charge at precisely 13.8V and pulling down to no more than 13.6V.
· The Scotty AI’s were auto-tuned to each alternator with these bedrock parameters. As expected, each alternator yielded slightly different tuning parameters.
· On starting the engines, the 12V house bank was charged first to 13.8V which is above float voltage of 13.5 for the lithium. The charge rate is slow at around 600W a side.
· Once the house lithium was at 13.8V, which was around 98% SOC, the Scotty AI’s started charging the 48V house at 1500W+ a side. Around 1A was pulled out of the 12V house, even when all the 12v loads were turned on.
· Scotty AI was able to hold the charge voltage at full power extraction without draining the connected 12V house battery.
What is Special about how these Problems are Solved?
1) There is auto-tuning for each alternator done by the AI program. So each Scotty AI is precisely tuned to each alternator and engine.
2) When the CAN connected 48V Lithium house battery calls for reduced current as it is rising in SOC%, the load is shared evenly between both Scotty AI units. They are treated as if one combined device.
3) After Auto-tuning each unit no other programming is necessary. The Master automatically finds the Slave and automatically changes its programming mode. The user just lets it run!
4) There is inherent Super Redundancy is this system. No computer programming or interaction is required.
5) When either engine is running, that Scotty AI charges the 48V Lithium. If the 12V loads are significant with motor sailing the other Scotty AI feeds 48V to 12V to meet the load demand if the single alternator is not sufficient power.
Note Scotty AI has provisional patent on auto-tuning and AI functions. Some of these features are used in this installation.
How Good’s That!