"Victron Comms" Epoch 460AH Lifepo4 8D Marine batteries

[Barking Sands]

I was testing the 300AH Essential batteries with Victron Comms but those ended up going to a buddy of mine. I opted instead for the 460Ah version X 2 that have the Marine IP67 case and some additional features. I figure for my small boat 920Ah should be more than enough.

They arrived a few days ago and today I put them on the bench and hooked them up to the Multiplus 2 and CerboGX and shunt etc. It didnt take long since it was the same hook up as the 300AH Essentials.

For the last few weeks I have been drinking from the firehose of information regarding Victron systems and how to configure lithium batteries and learning things like "tail current" and various other parameters that must be set to properly charge the batteries and then will reset the SOC meter to 100% when the batts are considered fully charged.

So these batteries out there that have "Victron Comms". Whats it good for other than displaying actual battery info on the Cerbo Touch 50 screen and then forwarding to the Garmin? Why would anyone really need that or want it. This basic question was not apparent when discussing "Victron Comms" and there really wasn't much info on the web that was readily available that went into details.

The off grid resources really are the best for this research. Better than most boat resources. At least for configurations and experimenting.

Anyways...as of the last week or so, much of the details I have gathered seem to have come down to just a few items of critical info:

1) in regards to something like the Epoch 12V300A V2 battery...the V2 does not stand for "Version 2" of this model battery. It describes the Victron V2 BMS protocol and lay out. There are other batteries that have had this feature for some time, but mainly for off grid, not marine batteries.

2) once the V2 capable battery is coupled to the Cerbo system you dont need to make any parameter changes. The battery BMS contains all the details. See the instructions below from Victron at the bottom labeled C. And this is the heart of the matter and what the "Victron Comms" do. All details, and commands come from the battery BMS for charging and discharging and temp control. I will of course confirm this with testing. I still have the shunt inline to use as a comparison. I can see both Epoch details alongside Victron Shunt details on both the Touch 50 screen and the Garmin plotter (via NMEA200).

One complaint about the Epoch is that the internal shunt threshold is not adjustable and does not register below 1 amp. So if your system is near equilibrium at say +/- .9 amps it will not register on the SOC over time. Over many days this will throw the SOC off. The Victron shunt this threshold is adjustable. If you dont hang around 1 amp or less that is not a problem and on boats "in use" you would rarely be under 1 amp draw or charge. I talked to Epoch yesterday and they said they are going to do something about that, but it will take a while.

A couple other features on this battery are:
1) it came with 2 harnesses. One is for a remote on/off switch that can be dash mounted. The other has the 10 segment SOC monitor that can also be remote mounted.
2) self heating- FYI the heating elements draw about 11 amps from the charge current.
3) Bluetooth
4) 97 lbs each!
5) IP67 waterproof. Everything is gasketed.

This is where I am so far. Still learning, reading and testing. I have the feeling this will be much more common in the future. As of now there are only a handful of batteries that have this but most are "server rack" style for off grid home systems.

I hope to be installing this set up in the boat in about 3 weeks.

 

[twistedtree]

Good point about "Victron communications", and what a vague term that is. DVCC is what you need for BMS control of charging, including shutdown of alternators for a compatible controller. With DVCC, the BMS continually broadcasts what current and voltage limits it wants, and chargers act accordingly. You don't need to program charge parameters or do anything other than connect everything together (and test, of course). If the batteries want a higher charge voltage held so them can do balancing, they will command it. And if the batteries have been sitting at full charge for an expended period of time, it can allow the SOC to drop down a bit, or otherwise provide a "storage" mode. I have discovered that you can also go into the GX device and manually reduce the DVCC voltage to lower SOC when you leave the boat. I did this the last time I left my boat, and it held the batteries at about 70% SOC while I was away. Very handy.

 

[Barking Sands]

TT..Thanks for validating the tip on the voltage setting in the DVCC. I discovered exactly the same thing and was wondering if that setting could be used in that way. I have been using that setting on the bench for the last week while I am at work to keep the SOC around 60 to 70% and it does appear to work well for that purpose. I think i had it set at 13.2 or 13.3 and the system seemed to idle in a more appropriate SOC for long term non-use. That setting is also easy to find and set. And if you forget you can do it from home via the VRM.

My initial intro to Victron and lithium had my head spinning for a bit. There is so much info out there to wade through and learn its hard to know what is pertinent. Only after a few weeks of studying, video watching and testing did a picture form. And now that picture is narrowed to just a few pieces of info. One of which TT added to above.

1) with a lifepo4 batt with "Victron comms" just plug it in to the Cerbo, ensure you have the data show up on the touch 50, enable the Dvcc setting

2) ensure the " max voltage" setting is set in the DVCC to what the batt calls out for. Usually 14.4 to 14.6 although I may end up slightly lower after testing.

3) when the boat is unused at the dock on shore power. Set the max voltage in the DVCC to around 13.2 or 13.3 or so to keep the batt to a more mid-level SOC.

I understand why Victron initially had a model of installer training and certification and had thier warranty the way they did. However I am glad they relaxed that.

Another battery with victron comms that appears to be suitable for marine use is the Canadian made Volthium batteries. They are a bit more expensive but they seem to be a solid choice.

 

[twistedtree]

I agree that it can be quite the chore to ramp up with the Victron stuff. The good news is that they are very open and there is tons of info out there. The bad news is that it’s poorly organized, if organized at all, so it becomes a giant treasure hunt trying to figure things out. And then there are all the things that don’t work according to specs which are equally important. Personal gripes are larger Quattros that never charge at rated output, even in cool conditions, and idle power draw that is double what the specs say. Victron is conspicuously silent in such issues.

 

[Barking Sands]

I agree that it can be quite the chore to ramp up with the Victron stuff. The good news is that they are very open and there is tons of info out there. The bad news is that it’s poorly organized, if organized at all, so it becomes a giant treasure hunt trying to figure things out. And then there are all the things that don’t work according to specs which are equally important. Personal gripes are larger Quattros that never charge at rated output, even in cool conditions, and idle power draw that is double what the specs say. Victron is conspicuously silent in such issues.

Right!?!

The organization issue is what had me going down so many non-pertinent rabbit holes. All very interesting, but not needed for my use.
I did discover many other things that I may implement later. Such as GUI mods to increase the amount of info on the Touch 50 screen. Also cheap wifi access point that only deliver small amounts of data. Other input such as tank monitors and senders, which I will add to my water tanks etc.

And the point you raise here is the main reason I made this post. To hopefully boil down the needed basics of what one might need to know if you get a Victron system with CerboGX and the smart lifepo4 batt with Victron comms.

It does greatly simplify things. Especially if you know ahead of time what is needed and what to expect.

On the flip side...a basic set of quality lifepo4 batteries (with bluetooth) and a non-Victron basic charger with basic lithium settings along with a good shunt monitor also looks very appealing from my new vantage point. If I had to start completely over knowing everything I now know..I am not sure what route I might take.

But I do like the Victron Multiplus pass through features.

One thing I do know...if I change boats in the future..these massive batteries are probably coming with me.:lol:

 

[twistedtree]

I agree that there is no single “right” answer for how to build any power system. There are lots of safe and acceptable ways to do it. So much depends on what you are starting with, how much you want to replace vs keep, budget, cruising style, etc.

 

[ScottD]

Barking Sands and Twisted Tree - thank you for this info. I just closed on my new-to-me Jersey 47 a couple of months ago (on the hard for the winter, now). She was a marina baby and so I've been outfitting her for life of actual use (primarily on a mooring/at anchor). Until now I've operated mostly on 12V but that just isn't feasible anymore. That lead me down the Victron and LifepO4 route. Many days and dollars later I'm still trying to get my head straight on how the victron system will work, and how to integrate into the existing circuitry. I've got everything at home, now on a bench and some wall panels I built for this purpose.

Barking Sands (or anyone, really) I do have a couple questions that I'll number so that hopefully it will be easier for someone else to follow (and benefit from) later down the line.

1. Have you figured out how you'll connect the new multiplus to your existing panel? I know that I'll have to switch the AC input from generator/shore power to the multi (though I rarely use the latter). I'm guessing that my existing switch on the actual panel will go away or be replaced, since everything will now route through the multi.

2. I understand that on the multi (MPII 3000 2x120) I can use the AC Out #2 for high-powered equipment (e.g. Aircon, water heater). However, it seems like it would be laborious for me to separate out those circuits from everything else for this purpose. Have you addressed this, and if so how?

3. Do you have a diagram that you've made, or are using as your reference for building out your system?

Thanks in advance for any advice that you have. I'm knee deep in this as well, and so once I have answers to some of these questions I'll put a diagram together and post that here as well. That said, Barking Sands you will probably beat me to that!

 

[ksanders]

Barking Sands and Twisted Tree - thank you for this info. I just closed on my new-to-me Jersey 47 a couple of months ago (on the hard for the winter, now). She was a marina baby and so I've been outfitting her for life of actual use (primarily on a mooring/at anchor). Until now I've operated mostly on 12V but that just isn't feasible anymore. That lead me down the Victron and LifepO4 route. Many days and dollars later I'm still trying to get my head straight on how the victron system will work, and how to integrate into the existing circuitry. I've got everything at home, now on a bench and some wall panels I built for this purpose.

Barking Sands (or anyone, really) I do have a couple questions that I'll number so that hopefully it will be easier for someone else to follow (and benefit from) later down the line.

1. Have you figured out how you'll connect the new multiplus to your existing panel? I know that I'll have to switch the AC input from generator/shore power to the multi (though I rarely use the latter). I'm guessing that my existing switch on the actual panel will go away or be replaced, since everything will now route through the multi.

2. I understand that on the multi (MPII 3000 2x120) I can use the AC Out #2 for high-powered equipment (e.g. Aircon, water heater). However, it seems like it would be laborious for me to separate out those circuits from everything else for this purpose. Have you addressed this, and if so how?

3. Do you have a diagram that you've made, or are using as your reference for building out your system?

Thanks in advance for any advice that you have. I'm knee deep in this as well, and so once I have answers to some of these questions I'll put a diagram together and post that here as well. That said, Barking Sands you will probably beat me to that!

What I would do is create a dedicated "sub panel".

On my boat I had from the factory three separate AC panels, each tied to either the generator or a dedicated shore power for that panel. My solution was to dedicate one of the panels to inverter powered loads, exchanging it's shore power input for the inverter output.

Another method if you had a single panel boat would be to cut the busswork on your panel, separating it into two panels.

 

[Barking Sands]

Barking Sands (or anyone, really) I do have a couple questions that I'll number so that hopefully it will be easier for someone else to follow (and benefit from) later down the line.



2. I understand that on the multi (MPII 3000 2x120) I can use the AC Out #2 for high-powered equipment (e.g. Aircon, water heater). However, it seems like it would be laborious for me to separate out those circuits from everything else for this purpose. Have you addressed this, and if so how?

Are you a 50 amp boat or 30 amp? Mine is 30 amp so that makes things significantly simpler and dont need AC out 2 at all since all of my loads and systems and generator and battery bank and MPII can power the panel consistently.

Shore power = 3600 watts
Gen = 4400 watts
MPII off battery= 3000 watts

If you are a 50 amp boat, KSanders idea seems like a simple options with minimal wire runs and changes. Its not something I have had to think about due to my small boats simple layout.

One thing I do recommend is to not restrict yourself to just boat sites and groups. I found much of the info I have learned recently came from off grid type websites, videos and groups as well as camper types.

 

[ScottD]

Are you a 50 amp boat or 30 amp? Mine is 30 amp so that makes things significantly simpler and don't need AC out 2 at all since all of my loads and systems and generator and battery bank and MPII can power the panel consistently.

Shore power = 3600 watts
Gen = 4400 watts
MPII off battery= 3000 watts

If you are a 50 amp boat, KSanders idea seems like a simple options with minimal wire runs and changes. Its not something I have had to think about due to my small boats simple layout.

One thing I do recommend is to not restrict yourself to just boat sites and groups. I found much of the info I have learned recently came from off grid type websites, videos and groups as well as camper types.

I'm 50A, so unfortunately it's a bit more work. I think in the short term I will just wire everything up together and rely on labeling/training to prevent the crew from trying to activate the high load items without the generator running. Our genset is 12.5kw so it powers everything when running. But, the goal is obviously to have a more fool proof system.

Next lay-up (when I don't have so many other critical items on my list) I'll either create a subpanel or just redo my existing panel since I've made some other changes already. I hate to lose the current panel since it is the original (and has the manufacturer logo on it, etc.) but I probably just need to get over that.

 

[Barking Sands]

I'm 50A, so unfortunately it's a bit more work. I think in the short term I will just wire everything up together and rely on labeling/training to prevent the crew from trying to activate the high load items without the generator running. Our genset is 12.5kw so it powers everything when running. But, the goal is obviously to have a more fool proof system.

Next lay-up (when I don't have so many other critical items on my list) I'll either create a subpanel or just redo my existing panel since I've made some other changes already. I hate to lose the current panel since it is the original (and has the manufacturer logo on it, etc.) but I probably just need to get over that.

It seems you could retain your original panel and possibly just group the items you want together by labeling them with say...a yellow label. The add a seperate mater breaker labeled yellow. Or it all the items for the AC2 could be moved to a particular section. Either way it will be a bit of work.

I have started color coding breakers for various things. Helps me keep track.

 

[Barking Sands]

here is an update in video format. Eventually the comm cables need to daisy chain and the data should be reported a bit differently. But as of now this is the only way I got it to work. Apparently Epoch and Victron are still working out some bugs. But it is perfectly usable as it sits.

https://youtu.be/wD2QCpnBNY0?si=jqeuv3gOkUCFrCq7

 

[eheffa]

VE.Smart comms?

@ Barking Sands

Thanks for your excellent videos.

I am awaiting delivery of two Epoch 460Ah batteries for my 12V house bank. (Some of my decision to purchase these was influenced by your assessment of these batteries.)

These new Epochs (920 Ah usable) will replace my 6x110Ah (~330 Ah usable) Firefly batteries.

I have a collection of un-networkable but programmable chargers; namely, a Magnum 2800W Inverter-charger along with another 40A Xantrex charger in parallel. The boat also has 550W solar and a 120A alternator with Balmar external regulator. These in combination could be used for charging when on the hook and running the generator but maybe aren't as suitable for when the boat is tied up at home on shore power.

In addition, to minimize generator time, I would like to add more AC charging capacity. (We have a 9.5 KW Onan generator so lots of reserve there...)

I am thinking that I might be able to add one or more Blue Smart IP22 30A chargers to round out my charging needs if they were able to communicate with the Epoch BMV's over BT. This might eliminate the need to go to the Cerbo GX, Canbus route...

I do have a BMV-702 shunt with Bluetooth dongle and note that it is supposed to be able to communicate to Victron Blue Smart chargers via the VE.Smart Network.

Do you know if the Epoch BMV can communicate with Victron chargers over the VE.Smart network?

Thanks for any thoughts on this question.

-Evan

 

[Barking Sands]

Hello Evan. The questions regarding what Victron components are compatible with batteries having the Victron communications protocol is something to research on Victron sites. But it is my understanding that the main component allowing for this networking ability is the Cerbo GX or the older Venus GX and then adding an inverter/charger that has the VE BUS. But I believe the Cerbo GX is the centerpiece of such a system from Victron.

Most use an inverter/charger like the Multiplus II but I think the Victron Energy Skylla-IP65 12-Volt 70 amp 120-240VAC Battery Charger may be compatible to if you just need a charger. Be sure to double check that though.

You definitely don't need to have that fancy stuff. You can just use your shunt and a compatible Victron charger to set up a good charge profile. Or use one of your existing chargers that has a lithium setting and use the Epoch app and your phone to monitor.

I still read nearly every day on the Victron world. Its quite extensive. Some of my favorite resources are youtube channel Off grid Garage , Explorist life as well as Ross Lukeman for the basics among many others. There is so much info to cover it is hard to know where to start sometimes. Binge watch youtube and read everything you can find, including the extensive Victron manuals and soon a more clear picture will form.

 

[eheffa]

Hello Evan. The questions regarding what Victron components are compatible with batteries having the Victron communications protocol is something to research on Victron sites. But it is my understanding that the main component allowing for this networking ability is the Cerbo GX or the older Venus GX and then adding an inverter/charger that has the VE BUS. But I believe the Cerbo GX is the centerpiece of such a system from Victron.

Most use an inverter/charger like the Multiplus II but I think the Victron Energy Skylla-IP65 12-Volt 70 amp 120-240VAC Battery Charger may be compatible to if you just need a charger. Be sure to double check that though.

You definitely don't need to have that fancy stuff. You can just use your shunt and a compatible Victron charger to set up a good charge profile. Or use one of your existing chargers that has a lithium setting and use the Epoch app and your phone to monitor.

I still read nearly every day on the Victron world. Its quite extensive. Some of my favorite resources are youtube channel Off grid Garage , Explorist life as well as Ross Lukeman for the basics among many others. There is so much info to cover it is hard to know where to start sometimes. Binge watch youtube and read everything you can find, including the extensive Victron manuals and soon a more clear picture will form.

Thank you. I appreciate knowing there are some alternatives. I will keep sleuthing this out.

I understand that allowing the Epoch BMS to dictate its care & feeding (charging) through the Cerbo GX is state of the art & optimal; but, I’m not keen on investing another $2K CAD & an added level of complexity to do that. (In retrospect, I wish I had gone with. Victron Multiplus inverter when I replaced the old Xantrex in 2018 but the Magnum still works.)

It seems to me that a good system could be achieved with a more modest investment but I’m not confident that this is true.

It seems to me that I have 2 quite separate charging states to deal with: Shoreside & off the grid ( ie underway & at anchor).

On shore power the boat is often sitting for days to weeks waiting for the next trip. There is no rush to get back to a full state of charge. (90% SOC might be optimal). In that situation I could easily get by with my Magnum charger setup with a custom LiFePO4 friendly protocol or just use a relatively low output 30Amp Victron IP22 charger that can talk to my Victron shunt. This should keep the Epoch’s in a happy SOC while tied up.

Off grid is a different story. When at anchor for days, especially in winter with little solar contribution, I would optimally like to replace our daily ~350-400 A/h draw with a daily generator run of 1 ½ - 2 hrs. I would be manually managing start & stop times with information from the Victron shunt & the Epoch app. In this case, I would really like to maximize the charging efficiency by using all the charging capacity at hand. I’m thinking that adding 2 of the 30A Victron IP22’s to the mix would give me a theoretical total steady charging capacity of ~ 220 Amps Our 9.5 KW generator would be quite happy driving that. (I never run the generator without being on board so could monitor & oversee the charging process.). If we are underway, we would be able to add another ~100A from the alternator getting us up to a pretty hefty 330A. Good enough methinks.

Would this be a reasonable option to start with?

I wonder what significant advantages there would be in opting for the much more expensive Cerbo GX / Canbus control system over the more manual scenario above?

- Evan

 

[Barking Sands]

Would this be a reasonable option to start with?

I wonder what significant advantages there would be in opting for the much more expensive Cerbo GX / Canbus control system over the more manual scenario above?

- Evan

I think its very reasonable. I think the Victron connected system would mostly affect you in time spent watching batteries and maybe provide a bit more efficiency.

And of course starting with what you have and testing/operating it makes sense IMO. If you get tired of monitoring the batteries or find yourself not having time to manage things then you can always move forward to take advantage of the batteries further capability. But if you will be running a generator to charge, you will be monitoring things anyways. I would bet you will be just fine.

I plan to use my generator as well until I get solar added.

 

[eheffa]

Thank you Barking Sands.

Much appreciated!

 

[ScottD]

eheffa - A comment and a question... I generally agree with Barking Sands about working with what you have and then adding later as you see fit. I would add though that at first I questioned the need for the cerbo with my system (I knew that I needed it, but given that everything had Bluetooth didn't understand why i should need it). I hadn't anticipated how much I would rely on the interface to monitor my system as a whole, and trend where my energy was coming from/going to. I'm not sure if your existing equipment has that, so just something to consider.

The question - you mentioned adding power from the alternator... I've been struggling with this one, and for now have decided to just wait and see how things go between solar and occasional generator (I'm on a mooring, and only have shore power when traveling and staying at a marina). My understanding is that with the Lifepo4 batteries I should have a DC-DC charger between the alternator and the 12V system. I'm really not clear what exactly the benefit of that is (other than "optimal charging", whatever that means), and, more importantly, the downside of not having one. Have you reviewed that, and if so what did you find?

For now I'm just going to have my engine and starter batteries live in isolation. But, it would be nice if I could capture some of that power (200 amps) when underway.

Barking Sands - please also respond to that if you have more insight into it.

 

[eheffa]

eheffa - A comment and a question... I generally agree with Barking Sands about working with what you have and then adding later as you see fit. I would add though that at first I questioned the need for the cerbo with my system (I knew that I needed it, but given that everything had Bluetooth didn't understand why i should need it). I hadn't anticipated how much I would rely on the interface to monitor my system as a whole, and trend where my energy was coming from/going to. I'm not sure if your existing equipment has that, so just something to consider.

The question - you mentioned adding power from the alternator... I've been struggling with this one, and for now have decided to just wait and see how things go between solar and occasional generator (I'm on a mooring, and only have shore power when traveling and staying at a marina). My understanding is that with the Lifepo4 batteries I should have a DC-DC charger between the alternator and the 12V system. I'm really not clear what exactly the benefit of that is (other than "optimal charging", whatever that means), and, more importantly, the downside of not having one. Have you reviewed that, and if so what did you find?

For now I'm just going to have my engine and starter batteries live in isolation. But, it would be nice if I could capture some of that power (200 amps) when underway.

Barking Sands - please also respond to that if you have more insight into it.

It seems to me that the recommendation to NOT have lead acid (LA) batteries in parallel with LiPO4 is questionable. This may have been a true maxim when using an external BMS to manage the overall current and voltage of the LiPO4 based house bank; but, from what I have read and reviewed, when using "drop-in" batteries with their own BMS, LA can co-exist in parallel with the LiPO4 without many issues.

Having LiPO4 and LA in parallel mitigates a number of issues. If the BMS were to go off-line with the alternator charging, one will not see a voltage spike that would cook the alternator diodes. ie. the alternator has an alternative current sink or buffer that protects it from a sudden BMS shut down.

In addition, allowing parallel Li / LA installation means the alternator output is not throttled or restricted by using lower output DC-DC converters.

The significant risk to the alternator is that the LiPO4 can accept virtually everything that the alternator throws at it, risking overheating and failure of the alternator. Even my relatively crude Balmar Ext regulator, allows alternator temperature monitoring and offers settings to derate the alternator to keep its operating temperatures to a safe level. Even if one dials a 120A alternator back to 100A, that is still much better output than needing three to four 30A DC-DC converters to accomplish the same.

-Evan

 

[ScottD]

It seems to me that the recommendation to NOT have lead acid (LA) batteries in parallel with LiPO4 is questionable. This may have been a true maxim when using an external BMS to manage the overall current and voltage of the LiPO4 based house bank; but, from what I have read and reviewed, when using "drop-in" batteries with their own BMS, LA can co-exist in parallel with the LiPO4 without many issues.

Having LiPO4 and LA in parallel mitigates a number of issues. If the BMS were to go off-line with the alternator charging, one will not see a voltage spike that would cook the alternator diodes. ie. the alternator has an alternative current sink or buffer that protects it from a sudden BMS shut down.

In addition, allowing parallel Li / LA installation means the alternator output is not throttled or restricted by using lower output DC-DC converters.

The significant risk to the alternator is that the LiPO4 can accept virtually everything that the alternator throws at it, risking overheating and failure of the alternator. Even my relatively crude Balmar Ext regulator, allows alternator temperature monitoring and offers settings to derate the alternator to keep its operating temperatures to a safe level. Even if one dials a 120A alternator back to 100A, that is still much better output than needing three to four 30A DC-DC converters to accomplish the same.

-Evan

Evan that is very validating, so thank you. That was how I was looking at it as well. If the Battery BMS is self-governing, than I don't have to worry about the battery. And any spikes should be absorbed by the "dumb" LA batteries. It's funny that despite being old technology they perform their job well, which is to thrive in what is essentially an unregulated wild-wild-west 12V environment (from the alternator).

I might try that, if I find myself needing more. At the very least it would reduce my watt-hours profile for all of the equipment that I'm running when underway (the MFDs, radar, autopilot, etc. etc.).

And yes - the amperage limitations on the DC-DC chargers are bananas. You'd have to spend a grand just to capture the power from a single alternator!

 

[eheffa]

Evan that is very validating, so thank you. That was how I was looking at it as well. If the Battery BMS is self-governing, than I don't have to worry about the battery. And any spikes should be absorbed by the "dumb" LA batteries. It's funny that despite being old technology they perform their job well, which is to thrive in what is essentially an unregulated wild-wild-west 12V environment (from the alternator).

I might try that, if I find myself needing more. At the very least it would reduce my watt-hours profile for all of the equipment that I'm running when underway (the MFDs, radar, autopilot, etc. etc.).

And yes - the amperage limitations on the DC-DC chargers are bananas. You'd have to spend a grand just to capture the power from a single alternator!

Hi again,

I'm still researching this topic of combining LA & LiFePO4 but apart from unsupported warnings ("Don't do it!"), people posting real world data are showing pretty favourable characteristics...

For example:
https://community.victronenergy.com/questions/119423/mix-agm-and-lifep04.html

I'm thinking that I will setup charging profiles to favour the LiFePO4 but expect that the LA will ride along in a pretty happy state. (esp since I plan to use 4 of my old Firefly 110 A/h batteries in the Stern thruster bank and they actually prefer to not be fully charged as a rule.)

-Evan

 

[Barking Sands]

Just an FYI, Victron has a new Buck boost DC2DC charger out soon that can do up to 100amps and I believe can be controlled by the Victron Bus so its fully programable. The Current Victron DC2DC chargers are just Wifi and are apparently 30amps but dont have a great reputation.

 

[eheffa]

Changing the topic a little:
Barking Sands-
I have emailed Epoch Support with this question but have not received any answer.

What bulk, absorption, float voltage / duration settings settings does Epoch or would you recommend ?

Does your Victron enabled system, under the control of the Epoch BMS (which should dictate optimal charging profiles), give you any insights you could share?

Thanks.

-evan

 

[twistedtree]

Using a parallel LA battery is really just a workaround for a BMS that doesn't provide any disconnect warning signal that can be used to turn off an alternator. So to work around that you put a LA battery in parallel that will not disconnect. But now you turn the possibility of a LA battery melt down into a likely dangerous situation because all the energy of the LFP system will discharge into a failed LA battery. This is why paralleling is not recommended in ABYC, and prohibited in ISO.



Another workaround to not having an external regulator with temp sensing and control is to add one or more DC/DC converters to charge LFP from LA. But for anything other than a small alternator, you will quickly spend more $$ on DC/DC chargers and get less output than with an external regulator.


For anyone diving into this, I would encourage you to try to build a system with a BMS that signals a disconnect, coupled to an external regulator that will maximize alternator output without overheating. It will perform better, is simpler, and is more likely to be/remain compliant with standards.

 

[eheffa]

Using a parallel LA battery is really just a workaround for a BMS that doesn't provide any disconnect warning signal that can be used to turn off an alternator. So to work around that you put a LA battery in parallel that will not disconnect. But now you turn the possibility of a LA battery melt down into a likely dangerous situation because all the energy of the LFP system will discharge into a failed LA battery. This is why paralleling is not recommended in ABYC, and prohibited in ISO.



Another workaround to not having an external regulator with temp sensing and control is to add one or more DC/DC converters to charge LFP from LA. But for anything other than a small alternator, you will quickly spend more $$ on DC/DC chargers and get less output than with an external regulator.


For anyone diving into this, I would encourage you to try to build a system with a BMS that signals a disconnect, coupled to an external regulator that will maximize alternator output without overheating. It will perform better, is simpler, and is more likely to be/remain compliant with standards.

Thank you Twisted Tree,

I clearly have more homework to do & will need to review the AYBC rules more thoroughly.

I do have a relatively crude Balmar external regulator controlling my 120A alternator that is driven by a serpentine belt (Cummins QSB 5.9) so it should be able to manage reasonable loads.

If the alternator output is directed through a 3 port Battery Isolator
eg
Ch1 AGM Start,
Ch2 AGM Thrusters/Windlass,
Ch3 LFP House,
would that not allow LA backup & protection to the alternator in case of BMS disconnect?

This would keep the AGM’s from being in parallel with the LFP house bank and one could have a higher output flowing from the alternator to the LFP House bank.

The alternator would be configured with an LFP optimized charging profile that, if not optimal for the AGM’s, would still not hurt them.

In order to keep the AGM’s in good shape, one could use a dedicated AC charger on the LA side of the collection using an AGM profile to occasionally condition or top up the AGM’s.

Alternatively, why not charge the AGM collection with the DC-DC charger & allow the alternator’s higher output to be directed, unrestricted, to the LFP House bank?

 

[mvweebles]

........
For anyone diving into this, I would encourage you to try to build a system with a BMS that signals a disconnect, coupled to an external regulator that will maximize alternator output without overheating. It will perform better, is simpler, and is more likely to be/remain compliant with standards.

Appears this is getting increasingly easy to do. There are now decent choices in batteries that have full monitoring capabilities (such as the Epoch and most Server Rack batteries). Within a year or two, many of the BMS issues will be a quaint piece of history.

I do not understand the inline lead-acid battery config. Balmar makes an Alternator Protect Module (APM) to protect against BMS shut down for about $80 if I recall, cheaper than a LA Battery (and certainly cheaper than a 30A DC-DC charger). Fronting LFPs with a lead-acid charger is sorta like pulling a car with a horse because you're worried the car may fail.

Peter

 

[eheffa]

As much as it would be quite possible to run a hybrid AGM and LFP system in parallel, (some people have done it successfully) the risks of catastrophic failure are there and the fact that it is not recommended or approved by ABYC makes it a no go for me.

As much as I hate to throttle the alternator output to the LFP house bank, the safest established route appears to be to use a DC-DC charger from the alternator to the LFP house bank and keep the LA and LFP separate. I'm not sure if Victron's Orion XS 50 Amp version is available yet...?

see proposed schematic attached:

The alternative for me is to go all in and replace the Magnum inverter charger with a Victron Multiplus, add the Cerbo GX etc and call it another $3K CAD boat expense...