My planned LiFePo4 Battery upgrade- comments & advice please.

[CJ13]

My electrical knowledge is limited- in particular my Lithium knowledge is limited to the info I’ve gleaned from previous posts here.
My boat is a Dutch built,12m steel river cruiser, which I keep in Netherlands. The work will be carried out over the coming winter, by a small scale builder of similar boats to mine. They have limited experience of LiFePo4, but appear to rely on Victron for advice.

My boat is 20 years old and much of the electrical system appears original. Existing setup consists of 3 x Mastervolt 225ah AGM Service Batteries + 1 x 225ah AGM Starter Battery. As well as the usual loads I have a Bow Thruster & Electric Anchor Windlass (rarely used!), which I assume are powered from the service batts.
Existing charging is via the Engine Alternator, Shore Power thro a Mastervolt Mass Combi 12/2000-100 charger inverter & 180w solar with Steca PR1515 PMW Controller.
The upgrade proposal from the yard is as follows:
3 x Victron Lithium SuperPack 12.8v NG 100ah batts- Instead of these I’m planning to supply 1 x Fogstar Drift Gen2 12V 628Ah Lithium Leisure Battery (Gen2)
Victron Multiplus-II inverter/ battery charger12/3000 120-32
Victron Orion XS 12/12-50A DC-DC battery charger
Victron Digital Multi Control 200/200A GX
Replace Battery Cable with 70mm2
Victron Smart Solar MPPT 100/30

With 3 charging sources do I need a Victron Cerbo GX, instead of or in addition to the Digital Multi Control?
Fogstar integrates with Victron & offer either Series or Parallel support- which do I need?

Any comments/ advice on the scheme appreciated!

 

[sealutions]

If you get a Cerbo GX and GX Touch then you can control everything from this including the Multiplus so you don't need the Digital Multi Control.

You are planning on just one Fogstar battery so it will neither be in parallel or series. But for clarity parallel is when usig multiple batteries to increase Ah capacity on your 12v system. Series would be if you have multiple batteries connected to increase the voltage for a 24v system:

* 2x 12v 100Ah batteries wired in parallel = 200Ah @ 12v
* 2x 12v 100Ah batteries wired in series = 100Ah @ 24v

 

[Baggywrinkle]

If you get a Cerbo GX and GX Touch then you can control everything from this including the Multiplus so you don't need the Digital Multi Control.

You are planning on just one Fogstar battery so it will neither be in parallel or series. But for clarity parallel is when usig multiple batteries to increase Ah capacity on your 12v system. Series would be if you have multiple batteries connected to increase the voltage for a 24v system:

* 2x 12v 100Ah batteries wired in parallel = 200Ah @ 12v
* 2x 12v 100Ah batteries wired in series = 100Ah @ 24v

I'd go further than that ... if you have a GX device, don't fit a Digital Multi Control at all.

Been there, done that, discovered that with a Digital Multi Control connected, because of the physical inverter switch, you cannot control the inverter from the App or the VRM as the switch on the digital multi control takes precedence - obvious really, can't have a device in a different state to the physical switch.

@CJ13 :

Consider remote monitoring via the VRM portal too - if you forget to turn the inverter off, or want to turn it on with a dehumidifier or heater attached, it can be done from anywhere. Battery SOC/Voltage etc. can also be monitored and you can have hours of fun analysing the statistics of your system usage.

GX Devices: The Cerbo GX and GX Touch cost about the same as an Ekrano GX which is a more powerful device with a built-in 7" screen - worth considering IMO. The Ekrano doesn't suffer from the limitation imposed by the combined USB/HDMI cable to the GX Touch (the supplied cable only allows a separation of 2m) - HDMI/USB can be extended, but might get a bit flaky, and it will add cost - best to co-locate the GX and Screen within 2 meters of each other (which is what the Ekrano does by integrating both).

Final point ... your Fogstar Battery comes with Victron integration, including DVCC (Distributed Voltage and Current Control) - which requires connection to a GX device. This is a very good way of taking care of the battery ... without DVCC, all the charging sources operate independently of each other so the charge stages & voltages in each charging device are not co-ordinated, with DVCC provided by the GX device, the solar, mains charger, and XS will be co-ordinated (they show up as "External Control" rather than "Bulk" "Absorption" etc.) and the charge profile decisions are all made centrally in the GX device. If you also have connection to the VRM portal, (via a GX LTE 4G) or your Marina WiFi, it will constantly log the battery cell data which helps enormously if you ever need to make a warranty claim on the battery (e.g. a rogue cell can't be balanced).





https://cdn.shopify.com/s/files/1/1347/0997/files/Gen2_Fogstar_Drift.pdf

 

[sealutions]

Perhaps I wasn't explicit enough but yes a Digital Multi Control is completely unnecessary with a GX device in the system.

A GX device is definitely the better option when using DVCC with multiple Victron devices for the reasons Baggywrinkle describes.

 

[Malish]

Stepping back a bit - if your professional boat builder has 'limited experience of LiFePo4' I would suggest a quick check with your insurers is in order

 

[geem]

I will throw a spanner in the works here and say that full integration as suggested is unnecessary. I wouldn't even advice installing any screen and certainly not DVCC control.
The BMS in my opinion should manage battery safety. Nothing else. Charging devices should manage themselves. DVCC offers little other than complexity when you actually need reliability. Victron devices are visible on Bluetooth. You can see all information you need on a tablet or phone anywhere on the boat without needing a fixed screen.
DVCC control of charging devices is totally unnecessary with lithium. Victron mppts, DC/DC chargers, shore power chargers can all be set to the same charge profiles. Its not like lead with long and possibly variable absorption period. Lithium has a balance period of a fixed duration, sufficient to balance the cells. You can adjust this to a minimum that achieves cell balance and then you are good to go.
There are some people that just love to have all this stuff talking to each other. I am not one of them. Years designing and working in data centres with computer controlled everything taught me that complexity does not mean reliability.
I run my own lithium system without any communication from battery to charging devices or inverter. Its simple and robust.
Having worked recently on fixing a victron integrated REC bms with numerous problems it reinforced my view that this is not the way to go for boats.
That system is being ripped out and replaced with standalone JK BMS based batteries and Victron smart shunt. The multiplus and existing mppts will look after themselves.
I would add that in my opinion you should have two lithium batteries in parallel. This provides you with some redundancy should a fault occur in one battery. I see you are suggesting a single 628Ah battery. I would install 2x 300Ah batteries with a class t fuse each and an isolator each

 

[PaulRainbow]

I will throw a spanner in the works here and say that full integration as suggested is unnecessary. I wouldn't even advice installing any screen and certainly not DVCC control.
The BMS in my opinion should manage battery safety. Nothing else. Charging devices should manage themselves. DVCC offers little other than complexity when you actually need reliability. Victron devices are visible on Bluetooth. You can see all information you need on a tablet or phone anywhere on the boat without needing a fixed screen.
DVCC control of charging devices is totally unnecessary with lithium. Victron mppts, DC/DC chargers, shore power chargers can all be set to the same charge profiles. Its not like lead with long and possibly variable absorption period. Lithium has a balance period of a fixed duration, sufficient to balance the cells. You can adjust this to a minimum that achieves cell balance and then you are good to go.
There are some people that just love to have all this stuff talking to each other. I am not one of them. Years designing and working in data centres with computer controlled everything taught me that complexity does not mean reliability.
I run my own lithium system without any communication from battery to charging devices or inverter. Its simple and robust.
Having worked recently on fixing a victron integrated REC bms with numerous problems it reinforced my view that this is not the way to go for boats.
That system is being ripped out and replaced with standalone JK BMS based batteries and Victron smart shunt. The multiplus and existing mppts will look after themselves.
I would add that in my opinion you should have two lithium batteries in parallel. This provides you with some redundancy should a fault occur in one battery. I see you are suggesting a single 628Ah battery. I would install 2x 300Ah batteries with a class t fuse each and an isolator each

I agree with most of this, keep it as simple and robust as possible. I would fit the Cerbo GX and Touch screen though. It makes a useful monitor for all devices in one place and allows use of the Victron VRM.

Also agree with the battery choice, a pair of 300Ah batteries is a better solution. I see no value in the "Gen 2" batteries in this install.

It's also worth noting that the Multiplus 2 LifePO4 preset has an absorption voltage of 3.55V per cell and a minimum absorption time of 1 hour. Those settings, used together, are too high.

 

[Baggywrinkle]

I will throw a spanner in the works here and say that full integration as suggested is unnecessary. I wouldn't even advice installing any screen and certainly not DVCC control.
The BMS in my opinion should manage battery safety. Nothing else. Charging devices should manage themselves. DVCC offers little other than complexity when you actually need reliability. Victron devices are visible on Bluetooth. You can see all information you need on a tablet or phone anywhere on the boat without needing a fixed screen.
DVCC control of charging devices is totally unnecessary with lithium. Victron mppts, DC/DC chargers, shore power chargers can all be set to the same charge profiles. Its not like lead with long and possibly variable absorption period. Lithium has a balance period of a fixed duration, sufficient to balance the cells. You can adjust this to a minimum that achieves cell balance and then you are good to go.
There are some people that just love to have all this stuff talking to each other. I am not one of them. Years designing and working in data centres with computer controlled everything taught me that complexity does not mean reliability.
I run my own lithium system without any communication from battery to charging devices or inverter. Its simple and robust.
Having worked recently on fixing a victron integrated REC bms with numerous problems it reinforced my view that this is not the way to go for boats.
That system is being ripped out and replaced with standalone JK BMS based batteries and Victron smart shunt. The multiplus and existing mppts will look after themselves.
I would add that in my opinion you should have two lithium batteries in parallel. This provides you with some redundancy should a fault occur in one battery. I see you are suggesting a single 628Ah battery. I would install 2x 300Ah batteries with a class t fuse each and an isolator each.

A screen lets you see the state of everything at a glance, instead of having to find your phone, open a Bluetooth app, and in Victrons case, cycle through the devices to see what is actually going on. A centralised display also has touch-screen control of the inverter, so it can be easily switched off or on as necessary, or shut down immediately from a single fixed point on the boat, without having to get to the inverter itself - the Victron BMS can also disconnect the batteries completely via a control on the touch screen, and the Victron relays can also be directly triggered if they are set up to do something important. It doesn't preclude back-up master switches, or BT Apps, it compliments them - the more options the better if talking about redundancy.

I fundamentally don't agree that the charge sources should scrap it out among themselves, and rely on the BMS to sort out the batteries. Independent charge sources attempt to provide their own take on the right charge voltage and phase while being unable to tell what is charge current and what is DC load - they may have voltage and current from the Victron shunt via BT but they still work independently, and they don't know about the other charge sources all doing the same thing.

I have DVCC up and running on my boat and it is very effective ... every charging device gets the same battery info and they all follow a centralised charge regime following the same charge profile and timing. When running, all the charge sources just sit in a state "ext. control" and I can watch the sources react when loads are removed or added, sometimes even switching off if other charge sources can provide the necessary boat load and charge current. The GX forces DVCC on if DVCC compliant devices are detected - which all Victron NG components are. It just works. All the chargers are set independently to the same Li profile anyway just in case I need a fallback.

... and the JK BMS supports Victrons DVCC ... so if a GX device is present, why not use DVCC? CAN communication has been used extensively in almost everything for the last 35 years and is very reliable.

How to get a JK BMS to work with DVCC - How To Connect A JK Inverter BMS To Victron CAN & DVCC

The real question is how hands-on and technical does the OP want to get? A single supplier system will plug together and work, mix and match components involves a lot of trial and error, unless someone can deliver a shopping list of components and a wiring diagram that is all tested and works.

 

[PaulRainbow]

<snip>

The real question is how hands-on and technical does the OP want to get? A single supplier system will plug together and work, mix and match components involves a lot of trial and error, unless someone can deliver a shopping list of components and a wiring diagram that is all tested and works.

I will only fit Victron DC-DC chargers, MPPT controllers, inverters, mains chargers etc. for the reasons you give here. I have done a lot of testing and have all of my own figures and settings for what works well. Some of those settings are not what people might think and are almost always not the Victron defaults. Settings can also differ between setups using the exact same components, but using the boat in different ways.

 

[Baggywrinkle]

I will only fit Victron DC-DC chargers, MPPT controllers, inverters, mains chargers etc. for the reasons you give here. I have done a lot of testing and have all of my own figures and settings for what works well. Some of those settings are not what people might think and are almost always not the Victron defaults. Settings can also differ between setups using the exact same components, but using the boat in different ways.

It seems the OPs original component list is all Victron, apart from the choice of battery, where the redundancy of 3 batteries was exchanged for a single Fogstar, which although not on Victrons supported list, it is supported by Fogstar to work with Victron kit.

I really like the DVCC logic, it takes all the guesswork out of configuring the various charge sources, and is all controlled in one place ... .




This is a Raspberry Pi which I am setting up with Venus OS Large so no other devices are connected yet, and it is not configured, - these are the DVCC screens which will apply to all charge sources implementing DVCC.

 

[geem]

A screen lets you see the state of everything at a glance, instead of having to find your phone, open a Bluetooth app, and in Victrons case, cycle through the devices to see what is actually going on. A centralised display also has touch-screen control of the inverter, so it can be easily switched off or on as necessary, or shut down immediately from a single fixed point on the boat, without having to get to the inverter itself - the Victron BMS can also disconnect the batteries completely via a control on the touch screen, and the Victron relays can also be directly triggered if they are set up to do something important. It doesn't preclude back-up master switches, or BT Apps, it compliments them - the more options the better if talking about redundancy.

I fundamentally don't agree that the charge sources should scrap it out among themselves, and rely on the BMS to sort out the batteries. Independent charge sources attempt to provide their own take on the right charge voltage and phase while being unable to tell what is charge current and what is DC load - they may have voltage and current from the Victron shunt via BT but they still work independently, and they don't know about the other charge sources all doing the same thing.

I have DVCC up and running on my boat and it is very effective ... every charging device gets the same battery info and they all follow a centralised charge regime following the same charge profile and timing. When running, all the charge sources just sit in a state "ext. control" and I can watch the sources react when loads are removed or added, sometimes even switching off if other charge sources can provide the necessary boat load and charge current. The GX forces DVCC on if DVCC compliant devices are detected - which all Victron NG components are. It just works. All the chargers are set independently to the same Li profile anyway just in case I need a fallback.

... and the JK BMS supports Victrons DVCC ... so if a GX device is present, why not use DVCC? CAN communication has been used extensively in almost everything for the last 35 years and is very reliable.

How to get a JK BMS to work with DVCC - How To Connect A JK Inverter BMS To Victron CAN & DVCC

The real question is how hands-on and technical does the OP want to get? A single supplier system will plug together and work, mix and match components involves a lot of trial and error, unless someone can deliver a shopping list of components and a wiring diagram that is all tested and works.

You have a single points of failure in the control of your charging devices. Not the end of the world but not ideal either. Canbus cables can and do fail in the marine environment. I fully understand that this is your baby. Its your bread and butter, but I much prefer the simple and more robust approach.
I am not going to hijack this thread but if you want to see why some very clever people dont use DVCC I suggest you visit the Cruisers Forum in the USA. The whole DVCC thing has been debated extensively and all the talent there says dont use in the marine environment

 

[CJ13]

Thanks for the replies- all very interesting!
I want a system that once set up just works. For my purposes the simpler the better.
Apart from the batteries all the kit will be Victron.
Paul says - ‘Also agree with the battery choice, a pair of 300Ah batteries is a better solution. I see no value in the "Gen 2" batteries in this install.’
I understand 2 x 300ah batts, but I want Victron integration- it’s not clear to me that non Gen 2 Fogstar’s have that?

 

[captainboo]

They don't according to their website. The Gen 2 gets the communication upgrade.

 

[geem]

Thanks for the replies- all very interesting!
I want a system that once set up just works. For my purposes the simpler the better.
Apart from the batteries all the kit will be Victron.
Paul says - ‘Also agree with the battery choice, a pair of 300Ah batteries is a better solution. I see no value in the "Gen 2" batteries in this install.’
I understand 2 x 300ah batts, but I want Victron integration- it’s not clear to me that non Gen 2 Fogstar’s have that?

How far with victron integration do you want to go?
You can't have simple and fully intergrated.
You can use a victron smart shunt to provide you with SOC and the MPPTS with battery voltage information.
What do you hope to achieve with full Victron integration that you wouldn't achieve without it?

 

[PaulRainbow]

Thanks for the replies- all very interesting!
I want a system that once set up just works. For my purposes the simpler the better.
Apart from the batteries all the kit will be Victron.
Paul says - ‘Also agree with the battery choice, a pair of 300Ah batteries is a better solution. I see no value in the "Gen 2" batteries in this install.’
I understand 2 x 300ah batts, but I want Victron integration- it’s not clear to me that non Gen 2 Fogstar’s have that?

If you want simple forget about Victron integration.

Set the BMS to protect the batteries and the charger profiles to do their job without tripping the BMS.

I have installed several LifePO4 setup as above and they just work. Whenever i do one i call in again after a few weeks and check everything is working as expected, so far, never a problem.

My own system is very similar to what you describe, except mine is 24V. Multiplus 2, XS1400 DC-DC charger, MPPT controller, Cerbo, Touch 70 etc. It all just works and everything can be monitored from the Touch 70 or the Victron VRM.

 

[Baggywrinkle]

Thanks for the replies- all very interesting!
I want a system that once set up just works. For my purposes the simpler the better.
Apart from the batteries all the kit will be Victron.
Paul says - ‘Also agree with the battery choice, a pair of 300Ah batteries is a better solution. I see no value in the "Gen 2" batteries in this install.’
I understand 2 x 300ah batts, but I want Victron integration- it’s not clear to me that non Gen 2 Fogstar’s have that?

The non-gen 2 Fogstar Drift doesn't but if you can find a pair of older first gen PRO versions somewhere, they do integrate with Victron to a certain extent and will probably be on discount as they have been superseded.
It's a cost vs. redundancy question - two smaller batteries cost more than one big one. Only you can make the decision if the cost of redundancy is worth it.

My boat was completely 12V, running from 6,6kWh of Victron GEL batteries, all the marine systems are 12V, winches, windlass, furling, bow thruster, bathing platform, instruments etc. I wasn't about to replace everything, so kept it, and I built an additional 48V system in parallel which has a further 10,2 kWh, I disconnected the 12V inverter and fitted a 48V Multiplus II, moving all the AC systems to 48V ... so my 48V system could fail completely, and with a couple of transfer switches, the solar can be switched back to the 12V system and I carry on. Everything is duplicated so when stuff fails, I lose capacity rather than function. The single points of failure are the Multiplus inverter/charger, and the Lynx 500 NG BMS - I currently don't carry a spare of either but my cruising ground doesn't currently necessitate that, I can get both on next day delivery. I will carry spares if I venture further afield.

As for the Victron integration, it really isn't that complicated IMO. Just connect everything together with VE.Can, VE.Bus and VE.Direct and it just sorts itself out, the GX gets its DVCC settings from the BMS, it recognises all the charging sources and puts them under ext. control, forces on DVCC, and that's it. It is prudent to programme the right profile into the MPPTs, Charger etc, - the settings are over-ridden by DVCC, but it's good to have them if the system needs to be reverted to individual chargers.

DVCC needs to be properly supported by 3rd party components, if not it will be more trouble than it is worth in a mixed ecosystem, which is where the problems come from. Works great with a Victron ecosystem though.

 

[Baggywrinkle]

Have a look at this Victron installer ... some of the best presented systems I've seen. They also do marine.

Off-Grid Electrical Specialists UK | Campervans, Motorhomes & Cabins



I used them as inspiration but still a bit rough around the edges ... and not finished.

 

[CJ13]

Thanks again for all the advice & comments.
On the basis of keeping things simple is there anything wrong with the following & simply setting each piece of equipment to the correct profile for LiFePo4?

2 x 300ah LiFePo4 batteries -perhaps not Gen 2?
Victron Multiplus-II inverter/ battery charger12/3000 120-32
Victron Orion XS 12/12-50A DC-DC battery charger
Victron Digital Multi Control 200/200A GX
Victron Smart Solar MPPT 100/30

Is there any benefit in introducing a Victron Smart Shunt?

As a follow up am I correct in thinking that the Bow Thruster & Windlass shouldn’t be powered by the LiFePo4 batteries?

 

[PaulRainbow]

Thanks again for all the advice & comments.
On the basis of keeping things simple is there anything wrong with the following & simply setting each piece of equipment to the correct profile for LiFePo4?

2 x 300ah LiFePo4 batteries -perhaps not Gen 2?
Victron Multiplus-II inverter/ battery charger12/3000 120-32
Victron Orion XS 12/12-50A DC-DC battery charger
Victron Digital Multi Control 200/200A GX
Victron Smart Solar MPPT 100/30

Nothing wrong with this, but i would fit a Cerbo GX and GX Touch rather than the digital multi control.

Is there any benefit in introducing a Victron Smart Shunt?

Yes, definitely fit one. Gives good monitoring and will pass accurate data to the chargers via the Cerbo.

As a follow up am I correct in thinking that the Bow Thruster & Windlass shouldn’t be powered by the LiFePo4 batteries?

That's correct, power these from the engine batteries or dedicated batteries.

You don't need to make things complicated by fitting the shunt and the Cerbo, you can just use them for battery/system monitoring and sending accurate voltage and current data to the chargers. If you wanted, you can connect tank senders to the Cerbo and varies other things. It can be a simple or as complex as you want.

This is what the GX Touch display looks like:

 

[CJ13]

Thanks Paul - that’s brilliant!