Bavaria 40: Upgrading to Victron MultiPlus and later LiFepPo - general questions

[Krumelur]

Hi,

I'm trying to remember the setup of the electric installation on board my Bavaria 40 (3 cabin, built 2009, model year 2010).
I want to replace the existing SBC charger with a Victron MultiPlus with built in inverter. Later, I also want to upgrade the service batterie to a LiFePo.

My batteries are both located under the seat bench in the salon in front of the navigation section. The current charger is an SBC 501FR (45A).

Questions:
- Is there a fuse and FI protection on board or does the 230V installation rely on such an installation on the pier?
- Are both batteries connected to the charger in parallel?
- When charging via the running engine: are both batteries charged in parallel or does one take precedence?
- I remember two batteries, 100Ah each. Is one the starter battery, the other service?
- If I install the Victron and replace the service batteries with LiFePos, would I need to keep the original charger for the starter battery?

Thanks!!

[symphony2]

Cant answer all your questions, but some simple ones. Your boat would have had a start battery of around 75AH and one or 2 house batteries (one bank) of around 100AH each charged from the alternator through a split charger giving precedence to the start battery - although in reality that needs little charge before it all goes to the house bank. The mains charger will have independent feeds to each bank and is capable of satisfying both banks at the same time although again the start does not need much.

Unless you are going to dramatically increase you on board consumption, for example by living on board full time, LiFePo is probably not the way to go. First thing to do if you want to use more on board capacity is to increase your house bank to around 350-400AH and install solar to deal with your daily consumption as much as possible. buy either serious lead acid such as Trojans if you plan continuous heavy use, or AGMs.

These are just suggestions as the first thing to do is to carry out an energy consumption audit to determine you typical daily use then look at the amount  of energy storage and renewal to support this. In other words start from the "problem" not from one particular possible solution.

[SYJetzt]

I agree with symphony concerning a diligent planning based on a clear use case.
It makes a big difference if you are on your boat for weekends and some weeks for holiday or you are a liveaboard and mainly on anchor without connection to landbased powergrid. If would suggest to install a battery monitor (like the victron bmv 712 or similar) first and get a deeper view in the real energy needs for you or your boat.
You need a balance between your energy demands, the storage capacity (AGM or lifepo) and the power source (onboard solar, wind, ..) or shore connection.

In my opinion the multiplus does not make much sense unless you have a (weak) generator on board. There are a lot of inverters with higher power and less cost on the market.
I have fitted my boat for bluewater cruising with lifepos, strong inverter and plenty of solar (900W), but had to pay for my mistakes not only in euros. Changing to lifepo isn't as straightforward as everyone thinks.
I kept my SBC charger (but had to adapt the charging settings) for charging the starterbattery and the housebank (lifepo) as well.
I overpowered and slaughtered my alternator due to high charging currents to the house bank (lifepo) if operated for longer periods at idling speed of the diesel.
i had to solve the issues with the BMS-system of the lifepo, which is switching off the load when battery gets discharged beyond a minimum voltage (pretty scaring if this happens when cruising at night leaving me in deep darkness without lights, autopilot, chartplotter,..) or is disconnecting the charging sources, killing the alternator or solar charger immediatly.

Besides the costs of such an equipment you need to do proper installation of the  system, which has really thick cables and lugs and represents real fire hazards due to the high currents if not done with diligence.   

Good luck
 

[Krumelur]

Thanks for your suggestions.

Looking at the specs of the SBC 501 FR I only see one output and not two. So it would be charging both batteries in parallel. I don't see how it would have two feeds, one for each battery?

As far as LiFePo goes: let's not get into pros and cons of it. What I'm interested in, is the situation where you have a lead acid starter battery and a LiFePo service battery (or battery bank). Would I need two separate chargers, or how is this solved? Both batteries have very different charging characteristics, so one sure cannot connect them in parallel.

[symphony2]

Not sure exactly which model battery charger you have,  but all the current Quick chargers have 3 outputs and it would be vert unusual for one that big to have only one output.

As SYJetzt says installing lithium batteries is nowhere near as simple as you might think and explains some of the potential problems. Your current installation is irrelevant - you have to throw it away and start again, finding out all the various permutations of charging and battery types.

Cannot stress enough the suggestion that you start from your anticipated power needs and then look at the alternative ways of meeting them. There are many ways of effectively meeting a typical 40' yacht's power needs with more conventional batteries and charging methods. This   forums.ybw.com/index.php?threads/270ah-diy-lifepo4-build.547680/ will give you a flavour of what is involved.

[paulemeier1]

Have done exact the same on my Bav 37CR 2006 last year.

There is an fuse for House Batteries indeed. Have a look behind the back of the seat above the batteries.
Have installed the 12/2000/80 very nice to have 220V every time....

Have installed to 200ah LiFePo4, so we could be without willpower for more than four days.

I have installed the viltron in the aft storage/back wall from the toilet. attention,  very strongly cable is necessary. I take 90mm2 to batteries.
But I am happy with it, i could not here any  ventilation sound in the Living room.

Than you have to put away the batterie splitter. Take booze cables from the alternator to batterie together and charge only starter batterie. If you do not do you alternator may dy oh to much heat.
To avoid it buy an Viltron Orion 30/12/12 B2B charger and put him between starter and House Batterie.

As optical Gimmick I choose the new curb gx with GX 50 touch to have all informations on one view.

i am very happy with it.

if you are german nativ speaker, let me know, i will give you more information in german

[SYJetzt]

I have the Quick SBC 501 in use. It has 3 separate charging ports and offers 40A charging current in total (all 3 ports together). In the original configuration it supplied the starter battery, the house bank and the battery for the bow thruster
It can be adjusted to 14,1V or 14,4V charging voltage in general, but not for every charging port in separate. I use the 14,4V, which fits the needs of my lifepo (4x3,60V=14,6V) and do not stress the lifepos. Due to the standard lead acid starter and bow thruster battery, which do not tolerate 14,4V in long term (will be cooked to death), i do not use the charger for the starter and bowthruster battery anymore. They will be charged by separate B2B chargers.
The battery charger is seldom used due to my energy sources from solar.
See attached manual