450: Just signed on a new 450s!

[CatNewBee]

Originally Posted by davedindubai

Hi CNB, I have a feeling you may well have all the power requirements on board in a spreadsheet somewhere?

If you do, would you share? I do love a spreadsheet.

Hi, sorry, I do not have a spreadsheet (yet).

I have done a different approach when re-fitting the electric system without using excel for the sizing.

We searched for a used catamaran of this size for liveaboard and to start our journey, I did not know what to expect from the electric system at this time.

What I did - was to think about, what I would like to have on board, assuming no vessel will have the perfect set up what I want to have.

So I just evaluated upfront how much I would have to cough up after buying a used cat to make it perfect - and what energy I would need to make the electric galley happen and how I would produce and store this energy. Regarding renewable energy usage, We have a RV for years that I had re-fit with solar and AGM batteries and I am pretty aware how they behave and how long they last, also was investigating for years LiFeYPO4 batteries and installations in that area.

So to make it short, the plan to use the largest available cells and the 5000W inverter charger along with the induction hob and the convection oven was in my mind already long before when visiting boat shows and searching for boats.

Then we found our boat and it was over-equipped for my taste, it has factory installed ONAN generator and 4 A/C units, also washing machine and 2kVA MassSine Mastervolt inverter plus the Dessalator 100DUO, that is a 12V and 220V water maker, also a solar installation 450Wp with a poor PWM regulator over the davits. I did not want the A/C and the generator, but kept them in place, the GEL batteries was half past dead and digging deeper I found the system inappropriate. I also had to remove the battery monitorMastervolt MasterShunt, it was way too weak for the task, and had to replace it by a Victron BMV 712 with 1000A.

The boat stays on the dry for the winter after the survey 1000km away from home, so I could not test, measure and evaluate the system during this time, but I could buy and test the parts I wanted to install - what I did.

My main goal was first to get rid of the old GEL batteries, 2 of the four were damaged - one had a cell short cut and was boiling, the other one has a high resistance cell, meaning it does not hold the voltage, it was just dead, also the start AGM battery was deep discharged and does not come back to life.

So first step was to remove the crap and fit the LFP with the balancer and solenoids to have a running 12V system again for the fridges and freezers to live a board and refit the boat (bottom job with copper coat, replace the propane by the electric galley, install the solar arc and the new controller, change the 220V installation with the new inverter. You can find the details and changes in my thread related to the LFP / galley.

To do this I digged up the wiring plans and checked out the circuitry and found much better ways to wire up and use the system.

Originally there are 2 separate 220V circuits ending on the switch panel, one for the shore power for the boat (outlets, washing machine, microwave, charger, water heater) and one for the A/C. The generator connects with 2 fuses to the switchboard and joins both when in use. The Inverter has relays that gives shore power priority hidden somewhere near the chart table.

My new setup is different. The generator output goes straight to the Victron Quattro inverter and then is distributed either directly to the house 220V installation, the relays are removed. The output also goes where the former output of the generator was to the A/C system to the switch panel. Now I can use the inverter to run the AC and the house, the generator can pass through the inverter to run both too, I can separate the A/C from the house by the switch panel and also can run AC on shore power either through the house line and power assist by the Victron Quattro, or by a separate shore line as original designed.

On the other hand the shore power panel for the shore line can now switch between the old inverter as Input and Shore power - that allows to team up both inverters to 7kVA using the power assist if needed.

The switch panel and all fuses remain, I have added some for the second Inverter and for the new galley appliances, that have isolated separate 220V wiring.

After finishing up the installation I had the first time the chance to really measure what on board uses how much power and what can run in parallel for how long without overwhelming the system. The checkpoints are:

- the REC-BMS - it measures and displays SOC, Ah, in and out, cell voltages, cell temperature, cell resistance, BMS temperature and battery voltage.

- the Victron BMV712 - it measures the Amps in and out, the Wattage, the Ah SOC and the system voltage. it is a little redundant but easy to read and it sends the data over BT to smart devices, and it has a programmable relay, that is very handy for my circuitry.

- the Victron Quattro has a USB MK2 interface, where you can configure it, and also measure all 220V and 12V currents, voltages and frequencies on the inputs and outputs there - using a computer - this helps to really find out what this devices use and how much power it draws on the 12V side to run them.

- The Victron SmartSolar MPPT 150/100 controller - it has its own retractable display and also sends all data via BT to smart devices, it measures incoming voltage and current on the solar, outgoing voltage, current and power and also accumulates Ah / Wh daily plus the times of bulk, absorption and float by day for 30 days.

This is how I've got the figures, but I have not did any estimations or spreadsheets upfront for planning or sizing. I was sure, my system will provide the power needed at any time simply by the assumption, that the factory installed system has done it before (with the factory optional upgraded system = 480Ah GEL usable 240Ah) and having now 4 times the capacity and 10 times the current and not needing the A/C at all. My main concerns were more the navigation systems and board electric for winches autopilot etc., fridges and freezers, water maker and the galley. I had an idea what it takes to re-charge such a battery and sized the appropriate solar array for the task given the available space aft.

It was during the spring sometimes quite chilly and I also used the dyson heater when living on board and re-fitting. During this time I also disconnected the shore power and used only solar, battery and inverter for everything for weeks, including the power tools I used for the re-fit - just to see how much power I possibly can produce and use off-grid.

Then we set sails for 5 weeks and never used a plug nor the generator a single time, staying in anchorages, making our own water, and using anything including A/C - as described.
During sailing I do have daily checked and logged the SOC and looked at the solar figures, also measured consumption of devices for curiosity, but have not done any spread sheet out of it, each day was different, we cope with good and bad weather periods and the system was ding just fine as expected. I have also not advised the admiral to be cautious with power and water consumption at all when she was cooking or washing during our trip, except to turn off the inverter when not in use. I wanted a realistic load profile.

This was the shake-down trial for the system and I am very confident, it will serve us well for the journey ahead.

[boom23]

Here's a spreadsheet I found and used when I was getting my Lagoon 450F setup. I hope it helps.

I original file extension was ".xlsx". I had to modify it to ".xls" to upload it. You might want to change the extension after you download it.

[CatNewBee]

Originally Posted by boom23

Here's a spreadsheet I found and used when I was getting my Lagoon 450F setup. I hope it helps.

I original file extension was ".xlsx". I had to modify it to ".xls" to upload it. You might want to change the extension after you download it.

Nice spreadsheet indeed, but ways over-estimated. Never seen a daily consumption of 1200Ah, even with extensive cooking. And there are no A/C yet in the usage.

Running the cat with 2 fridges and freezer at anchor is about 300Ah..400Ah per day, sailing about 400..500.

I am just curious, you run your watermaker for 6 hours when sailing and for 12h at anchor?

[boom23]

I played with this spreadsheet 4 years ago. I do not remember what numbers are in there and why. But, it can be a great start for you guys.

From the top of my head regarding watermaker running times, it is better to have a lighter ship during crossings. Also, cruisers tend to use more water at anchor (clothes washing, more showers, wash boat, etc.). So, less running times while crossing and more running when at anchor.

[CatNewBee]

I was curious, because we run it daily for 1 hour to top up the 100l we use per day, if we run it 12h we would end up with 1200l, and will likely sink the boat in less than a week.

[boom23]

Originally Posted by CatNewBee

I was curious, because we run it daily for 1 hour to top up the 100l we use per day, if we run it 12h we would end up with 1200l, and will likely sink the boat in less than a week.

It depends on the size of your watermaker, water tank, consumption rate, etc.

You can modify the spreadsheet to make it match your boat's equipment and your requirements. Enjoy!

[davedindubai]

I’ve just one thing to say “BOOM!”. See what I did there?

You nailed it, that spreadsheet is awesome!
Thanks.
Once I’ve adjusted to my exact set up I’ll repost for anyone interested.

[aelyafi]

Hi Dave. Can I ask you how many winches came with the boat without you having to pay any extra? Was there a winch somewhere to be used for the spinnaker?

[davedindubai]

Just the 3 at the helm. The one in the middle being Electric for the main halyard but you can furl the Genoa using it too. All are 60’s.

The spinnaker winches comes as part of the pack at $4000, inc sprit etc.

I’d recommend getting the spinnaker pack. I use the winches for the Genoa most days if nothing else (downwind).

[Zenit]

Originally Posted by Yatt

Is the 11kVa Onan generator necessary to run the Cruisair AC (48.000BTU) which Lagoon sells? Or would the 4 kVa Onan be strong / good enough to run just one AC - nor for cooling only but for heating too?



Lagoon could not answer this questions, they told me to go for the 11 kVa, but I like the smaler generator more as it is only half the weight and the fuel consumption ist much less. And it is about 6000 USD cheaper.



Does anyone of you have a 4kVa genset running with the Cruisair AC?



Thank you!

4kVa will be ok to start 2 AC. It was on my Lagoon 450 (2012) with no problem

[davedindubai]

Originally Posted by Zenit

4kVa will be ok to start 2 AC. It was on my Lagoon 450 (2012) with no problem

We have a 6.5kva and personally I wouldn't recommend going any smaller on a 450, unless you plan 2000w of solar.

6.5kva gives us the luxury of being able to do multiple 220v jobs at the same time to limit genset run time. I like the quiet.

[CatNewBee]

Personally I would built it different, one A/C for the master bed room with air diversion to the salon. Then a smaller generator - 4...5 kVA, and a dive compressor in the same compartment. Additionally a diesel water furnance for sailing high lattitudes and making hot water if wanted.

You gain a lot of storage and much less clutter. Unfortunately you cannot order this configuration.

[davedindubai]

Originally Posted by CatNewBee

Personally I would built it different, one A/C for the master bed room with air diversion to the salon. Then a smaller generator - 4...5 kVA, and a dive compressor in the same compartment. Additionally a diesel water furnance for sailing high lattitudes and making hot water if wanted.

You gain a lot of storage and much less clutter. Unfortunately you cannot order this configuration.

I looked into splitting 1 AC unit for 2 cabins and it's a no go really. You lose all the efficiency of the unit due to long and awkward runs of ducting, or you would have to go for a larger unit than I wanted which makes it more of a power drain.

I have a 6.5kva and can easily fit the dive compressor in the same locker plus I can make water, heat water and put the kettle on at the same time.

[Darksyde]

Dave,

i have AC and I used it maybe once this year . So if you are not planning to
go Turkey in August or stay longer in a Marina there is no need here in the med.

Even with the Baby you will not cool down a lot .

Think more about heating :-)
i am thinking of a Diesel heater

My two cents .

M

[CatNewBee]

I agree, there are so many blue water cruisers circumnavigating the world along the equator without a A/C unit, I do not need all the rooms to be cooled, it is already luxury to have one chilled. Also all the throughhulls are not necessary and a potential safety thread.