question

Hi,

we are refitting the electrical side of our catamaran before moving aboard for longer periods.
Having heard a lot of good things of the Victron equipment, but also hearing that it is fairly pricey I wonder what at least cost workable solution would be for us.

Maybe here is knowledgable enough to suggest specific models of what we should get as a minimum configuration. I am hesitant to contact a dealer right now, because they tend to want to sell what makes them the most money.

So here some details two schematics and a load balance attached.

CIRCUMSTANCES:

1. We will live more or less permanently onboard.
2. We intend to cruise only in warm climates.
3. We are from Europe, so our AC system is geared towards 220V and ideally we buy stuff from European suppliers.
4. Typically (80-90% of time) we are preferring to anchor instead of going into marinas.
5. We are on a budget & prefer to change only the components we really need to change to make the planned system with the LiFePo batteries work.
6. Our current batteries are pretty much shot and as space & weight are equally an issue as budget is, we intend to get 2-3 sets of these: https://bit.ly/3cRAiJr as recommended in this video https://bit.ly/3r8wOHN.
   At 460€ per set including shipping to Germany they beat AGM an Lead Acid easily.
   We are aware that there may 1-2 faulty cells in the delivery which might need immediate replacing, but feel its a risk worth taking.
7. Our current system is completly 12v. As we do not intend to run high current items from the batteries, we currently do not intend to switch to a 24v system.
8. As I am still working in computer graphics (www.das3Dstudio.de) and will continue doing so from the boat, I need to power my high performance PC.
   We thought about doing this with solar, but, the power draw will be to much. We will use solar though for our house battery system.
   A less power hungry machine is not an option, quite the contrary, I may eventually need to add a second external RTX2070 graphics card.
   So looking at other options we decided to get a small Honda EU 10i genset dedicated to this.
   It will be much more quiet than our main genset, as it can power the PC in Eco mode.
   Fuel is not an issue either, as our main engines as well as the main genset run from petrol anyway.
   We will eventually add third LiFePo4 pack to run the work PC occassionally overnight.
9. We do NOT have diesel engines and alternators.
10. Batteries will be located on the bridgedeck but within living quarters, so lead acid is pretty much out as a solution.
11. We do want to keep our existing fridge ;-)
12. We will add the separate freezer.
13. Our current genset is fine for running the desalinator and power tools or even a heater, but it is to loud to run the work PC over extendet times.
14. The Starlink antenna is planned in for business later, but currently not yet available for mobile platforms and their planned mobile unit might be slightly different. Currently they say the antenna daws 100w.

QUESTIONS (Please suggest specific models & (possibly European) suppliers if you can):
BMS

a)

We need a battery management system (BMS) for our batteries. Our intendet battery packs have 280Ah each. Charging will happen mainly via the four solar panels and the windgen.

Is this one https://bit.ly/2QlydxL suitable?

b)

I understand we need to „top balance“ the cells before starting to use them. Should/do we need to also install an auto leveller?

We prefer to have less risk of killing the batteries if we forget to to switch something on.

SOLAR CONTROLLER

a)

We have two Sunware Fox100 Solar controllers from our old solar panels. Do we absolutly need to change those, or can they be reused with the new 300w panels & LiFePo4?

b)

If we need new controllers , which are suitable controllers out of the Victron range please, suggest specific models suitable for our set up with four 300W panels. Our panels will be non flexible industrial 48V panels.

Remember we are on a budget.
c)
Do we need one solar controller per panel?
d)
Our Rutland 1200 Windgen controller (Manual here https://bit.ly/394RuKC) has a solar controller terminal too and can accept up to 20A from the panels.
Can/should we use it to also control one of the PV panels? The Rutland controller has the ability to stop the windgen once a specific voltage has been reached by reversing its internal polarity.
Can this be engaged in combination with the Victron BMS?

SOLAR PANELS

For now we will get 4 new 300w panels. We have no issue using industrial grade panels as long as they are saltwater proof (which they also need besides Highways...). We prefer hard non flexible panels. Open to suggestions.

While looking into this, I found this pretty handy site by the European Union: https://bit.ly/316K2Kg

Some may find this helpful too.

CHARGER

We currently have a Dometic Waeco 1250 50A charger to charge via Genset or Shore power. It can handle 220V & 110V AC input.

a)

Do we need to upgrade it? As far as I understand it can be used for LiFePo4 charging when the dip switches are set accordingly.

b)Usually we plan to charge from solar and wind, the charger is a back up. So 50A from it should suffice. No?

c)

On the odd occassion on which we are actually in port we are usually docked for several days, so the 50A charging should suffice, no?LiFePo4 are said to pose less risk fire/explosion risk than standart LiPo batteries.

Still, is it a good idea/a necessity to use a metal battery case?

Maybe with a non combustible insulation of glass cloth inside facing the battery cells.

STORAGE

What happens if we need to leave the boat over an extendet period? In the past with AGM we could simply leave the batteries hooked up to solar. Is that possible here too? Or should it be done different?

LOAD BALANCE SPREADSHEET
Link to load balance spreadsheet:
https://www.filehosting.org/file/details/931152/35ft%20Catamaran%20Electric%20Balance%20Liveaboard%20Rev00%202021-03-15.xls

THE BOAT


CHARGING SCHEMATIC

CONSUMER SCHEMATIC