Epoch Made All What We Want

[JeffOnTheBoat]

Okay, this thread has gotten very technical. If I wanted to keep it as simple as possible, I still want to know would this Epoch 460AH battery work with my Boat system Victron multiplus, wakespeed, Cerbo GX system with fully working canbus with out to much fuss? The conservative alternative is two Victron 200AH batteries that are proven to work with the above. Just checked the pricing, $1000 each so about the same price. I would like to purchase the single denser Epoch but worried. Any thoughts about keeping it easy?

[rgleason]

Originally Posted by JeffOnTheBoat

Okay, this thread has gotten very technical. If I wanted to keep it as simple as possible, I still want to know would this Epoch 460AH battery work with my Boat system Victron multiplus, wakespeed, Cerbo GX system with fully working canbus with out to much fuss? The conservative alternative is two Victron 200AH batteries that are proven to work with the above. Just checked the pricing, $1000 each so about the same price. I would like to purchase the single denser Epoch but worried. Any thoughts about keeping it easy?

Exactly how much integration do you want with your Wakespeed?

Do you want the Epoch BMS to control the alternator?
The 460ah Epoch with Canbus Communication does communicate with CerboGX (I believe using DVCC protocal). Ben Stein (Panbo) has done tests with it, but it is unknown yet if the wakespeed ws500 responds to the battery's signals through the CerboGx. Users of the new battery are trying to determine this and Epoch has contacted Wakespeed engineering but has had no response. Take a look at Ben's post in the Facebook Group https://www.facebook.com/groups/2935...?q=ben%20stein
and Panbo.

If you have designed your system to protect the Alternator and your equipment from a BMS load dump, then you can create what Al at Wakespeed calls "a box within a box" by setting Wakespeed WS500 parameters to operate within the Epoch battery parameters. This will work provided you monitor the batteries and balance them when necessary.

I hope this helps to answer your question. Capt Rivet, Wholybee and others will have other observations and considerations.

[SOLAR SUPPORT]

Epoch or Victron? Actually, that's not the whole point. It is important to safely convert LA service batteries to Lifepo4 batteries. Millions of boats and caravans using LA technology cannot safely use the Lifepo4 service battery by directly connecting the two poles of the battery with the drop-in concept. The most important problem encountered here is the lack of direct communication between the alternator and the Lifepo4 battery BMS.

It is quite natural that alternators produced for LA technology for many years do not have this feature. The old alternator needs to be made compatible with the LI bms. Although it is initially possible for the alternator adjusted in this way to work in harmony with the BMS, problems with its continuity continue. The balance of the LI cells gradually deteriorates over the long term, resulting in the alternator external regulator charge cut-off circuit not working before the BMS shuts down the battery. The result is obvious: you will have to replace the APD or alternator and other damaged sensitive electronic devices with new ones.

There is no newly designed Alternator yet that can communicate directly with the Lifepo4 battery BMS. It is a major deficiency that the BMS, which is designed for the safe and long-lasting use of LI cells, does not have a simple hardware that gives a warning before isolating the battery from the entire system. Perhaps alternator manufacturers are waiting for the lack of pre-shutdown warning equipment in the BMS to be addressed to add a simple on-off device that will allow newer model alternators to be safely stopped while running. I wonder if bms developers are also waiting for Alternator manufacturers?

Of course, thanks to the communication protocols developed, safe operation of the BMS and alternator can be ensured. Meanwhile, the compatibility of communication protocols with each other is another problem. However, for simpler electrical systems, which constitute the majority, neither BMS developers nor alternator manufacturers care about closing this simple security vulnerability.

[wholybee]

Originally Posted by SOLAR SUPPORT

Epoch or Victron? Actually, that's not the whole point. It is important to safely convert LA service batteries to Lifepo4 batteries. Millions of boats and caravans using LA technology cannot safely use the Lifepo4 service battery by directly connecting the two poles of the battery with the drop-in concept. The most important problem encountered here is the lack of direct communication between the alternator and the Lifepo4 battery BMS.

It is quite natural that alternators produced for LA technology for many years do not have this feature. The old alternator needs to be made compatible with the LI bms. Although it is initially possible for the alternator adjusted in this way to work in harmony with the BMS, problems with its continuity continue. The balance of the LI cells gradually deteriorates over the long term, resulting in the alternator external regulator charge cut-off circuit not working before the BMS shuts down the battery. The result is obvious: you will have to replace the APD or alternator and other damaged sensitive electronic devices with new ones.

There is no newly designed Alternator yet that can communicate directly with the Lifepo4 battery BMS. It is a major deficiency that the BMS, which is designed for the safe and long-lasting use of LI cells, does not have a simple hardware that gives a warning before isolating the battery from the entire system. Perhaps alternator manufacturers are waiting for the lack of pre-shutdown warning equipment in the BMS to be addressed to add a simple on-off device that will allow newer model alternators to be safely stopped while running. I wonder if bms developers are also waiting for Alternator manufacturers?

Of course, thanks to the communication protocols developed, safe operation of the BMS and alternator can be ensured. Meanwhile, the compatibility of communication protocols with each other is another problem. However, for simpler electrical systems, which constitute the majority, neither BMS developers nor alternator manufacturers care about closing this simple security vulnerability.

I don't think alternator communication is important except for edge cases. Boats are an edge case, and even most boats don't need it.

Here is a question. If instead of a second battery, there is some other high draw in the circuit. Lets say, the ignition system of a truck, along with headlights. Would that draw be enough to prevent a load dump? LOTS of people put drop-ins in RV's with nothing at all. No APD, no DCDC charger, just a direct swap. They work fine. The house batteries are located a distance form the engine, so the long wire run limits current. There are other large loads on when the engine is running, so a load dump is unlikely. Considering that the BMS would only disconnect in the event of a problem, a load dump is VERY unlikely.

Boats are an edge case. There are thousands of boats with LFP. There are certainly some that can justify alternator control. But the majority do not have it. And the forums are not filled with posts "I fried everything because I installed my LFP wrong!" Are there ANY threads here from someone that had a load dump and fried everything?

So anyway, I don't think it is a deficiency if a BMS doesn't communicate with the alternator. For the edge cases that need that, plenty of BMS's support it, as do several alternator regulators.

[SOLAR SUPPORT]

Originally Posted by wholybee

I don't think alternator communication is important except for edge cases. Boats are an edge case, and even most boats don't need it.

Here is a question. If instead of a second battery, there is some other high draw in the circuit. Lets say, the ignition system of a truck, along with headlights. Would that draw be enough to prevent a load dump? LOTS of people put drop-ins in RV's with nothing at all. No APD, no DCDC charger, just a direct swap. They work fine. The house batteries are located a distance form the engine, so the long wire run limits current. There are other large loads on when the engine is running, so a load dump is unlikely. Considering that the BMS would only disconnect in the event of a problem, a load dump is VERY unlikely.

Boats are an edge case. There are thousands of boats with LFP. There are certainly some that can justify alternator control. But the majority do not have it. And the forums are not filled with posts "I fried everything because I installed my LFP wrong!" Are there ANY threads here from someone that had a load dump and fried everything?

So anyway, I don't think it is a deficiency if a BMS doesn't communicate with the alternator. For the edge cases that need that, plenty of BMS's support it, as do several alternator regulators.

"Burying your head in the sand like an ostrich" on this issue is not an option. Just search the topic on Google. You will find that the results are not what you thought.

[rgleason]

Although it is initially possible for the alternator adjusted in this way to work in harmony with the BMS, problems with its continuity continue. The balance of the LI cells gradually deteriorates over the long term, resulting in the alternator external regulator charge cut-off circuit not working before the BMS shuts down the battery. The result is obvious: you will have to replace the APD or alternator and other damaged sensitive electronic devices with new ones.

While this may be true, if you have some solar (3-6 amp output) with good MPPT controllers, I am told, the Dropin LFP can be top charged and will balance the cell differential (even faster if the battery has a 2a active cell balencer), also the alternator can be used for this purpose, although it might take a long time with the engine running. How often to top balance? Read the previous posts, it depends on many things.

There is no newly designed Alternator yet that can communicate directly with the Lifepo4 battery BMS.

This is not phrased properly. There are alternator regulators that will accept communications from a BMS responding to the batteries needs and protecting the alternator from load dump. Zeus and Wakefield come to mind. However these regulators must be paired with certain BMS that have been engineered for the right communications. Generally these are external BMS and are not found in Dropin LFP batteries, however there are signs that this situation is slowly changing.

In am coming to the conclusion that there is another way to solve the problem with Dropin LFP not communicating the necessary information to the alternator regulator. Like Whollybee, I am considering a simple system that uses an Victron Argofet to protect the Alternator and Nav Equipment from load dump. This allows the Dropin LFP to simply do what it wants without having to communicate with the outside world. Then the problem becomes concern about about the health and care of the Dropin Cells, which may get further and further out of balance over time, (causing more frequent BMS shutdowns). However using a Dropin LFP Battery with 2a active balancing with 100watt solar panel (100/12=8.33amps at full power) and a Victron MPPT regulator, I am pretty certain that the cell differential can be maintained to be quite low, depending on use. For example, a live aboard might want to curtail power use for several days when they are top balancing, and for a boat that never sees the dock but is on a mooring awaiting its owner, this is a perfect time for top balancing.

I have no doubt that the best system to have is a regulator properly controlled by the LFP BMS (Generally found in Victron Systems Mastervolt and a number of External BMS/DIY LFP Batteries ). In fact, the BMS really should control all "chargers" This is the type of system I favored installing until I designed one for our small boat, with the help of others more knowledgeable and experienced, and I learned that these systems are generally more expensive and much more complicated. I have been waiting and learning since then, and am now considering this approach.

[CaptainRivet]

So much theories....

Use your alternator only for bulk charge till 13.8V and you can never have a problem with the earlier disconnect with aging cells, deviation and a BMS that has 2A active balancers or even Li-time surprise boxes with passive balancer without external communication.

An alternator is the worst efficent charge source on a vessel and using it above 13.8V (or equivalent to 24 or 48V systems) makes 0 sense (for the last 5AH) and just calling for trouble. Keep things simple.
And an LiFePO doesn't have to be fully charged all the time, its actually no problem with good cells not to be in the knee >3.4V for over a month without being out of balance, especially if your bank sees <0.3C charge and discharge which is common in marine use. absolutly no issue doing that....again so much lead thinking...

Solar or shorepower charger is perfect for doing the rest, Alternator the worst with major risks for the whole system. And yes charge your surprise boxes without external communication to 3,65V=14.6V (if the manufacturer is not explicitly stating different, then use this...if stated 14.2-14.6V use 14.6V) as the tiny passive balancer needs that time to get or keep it properly balanced and thats your only indication how well your battery is doing...if it shuts of at 14.2V you know you have a problem and its out of balance but you can still rescue it without cutting open...charging to 14.2V you won't realize till too late and balancer has not enough time to do its job properly. That damages the cells more then even keeping it fullly charged at 14.6V for weeks. And you don't hurt your battery charging it to 3,65V, it is speced to do that and cycle life is between 2.5V and 3,65V given. Just don't keep it at 3,65V for days or weeks...
Lifepo4, even tested cheap dropin or ok DIY build banks with a well tested BMS are much more reliable, totally maintenance free and much more constant over time then any lead can ever be.
Stay to basic rules and keep it simple and you have a troublefree battery.

If you have full communication from BMS, real experience (not from watching 20 youtube videos, yes they help but cannot replace experience) and access to cells you can optimize that to 3,45-3.6V as you can always correct it if you see you get a runner...but if you are in the dark don't try to do it, you will create more damage then optimzing can ever do good. Experience dealing with lithium for 20 years and paid my lessons....Amen

[SOLAR SUPPORT]

Originally Posted by rgleason

While this may be true, if you have some solar (3-6 amp output) with good MPPT controllers, I am told, the Dropin LFP can be top charged and will balance the cell differential (even faster if the battery has a 2a active cell balencer), also the alternator can be used for this purpose, although it might take a long time with the engine running. How often to top balance? Read the previous posts, it depends on many things.


This is not phrased properly. There are alternator regulators that will accept communications from a BMS responding to the batteries needs and protecting the alternator from load dump. Zeus and Wakefield come to mind. However these regulators must be paired with certain BMS that have been engineered for the right communications. Generally these are external BMS and are not found in Dropin LFP batteries, however there are signs that this situation is slowly changing.

In am coming to the conclusion that there is another way to solve the problem with Dropin LFP not communicating the necessary information to the alternator regulator. Like Whollybee, I am considering a simple system that uses an Victron Argofet to protect the Alternator and Nav Equipment from load dump. This allows the Dropin LFP to simply do what it wants without having to communicate with the outside world. Then the problem becomes concern about about the health and care of the Dropin Cells, which may get further and further out of balance over time, (causing more frequent BMS shutdowns). However using a Dropin LFP Battery with 2a active balancing with 100watt solar panel (100/12=8.33amps at full power) and a Victron MPPT regulator, I am pretty certain that the cell differential can be maintained to be quite low, depending on use. For example, a live aboard might want to curtail power use for several days when they are top balancing, and for a boat that never sees the dock but is on a mooring awaiting its owner, this is a perfect time for top balancing.

I have no doubt that the best system to have is a regulator properly controlled by the LFP BMS (Generally found in Victron Systems Mastervolt and a number of External BMS/DIY LFP Batteries ). In fact, the BMS really should control all "chargers" This is the type of system I favored installing until I designed one for our small boat, with the help of others more knowledgeable and experienced, and I learned that these systems are generally more expensive and much more complicated. I have been waiting and learning since then, and am now considering this approach.

By looking at your profile picture, I understand that you are the owner of this cute and beautiful sailboat. My boat is about the same size. Therefore, I can approximately estimate the size of your budget allocated for safe Lifepo4 battery transition. On a boat using a Lifepo4 battery, whether the BMS is inside or outside the battery affects the installation cost considerably. I think you have researched the cost of installing a system with an external BMS, advanced charge-discharge control mechanism and central data processing unit, as well as a special communication screen, on your boat. These advanced and complex systems must have an algorithm that guarantees safe alternator charging through alternator regulator and external BMS communication. I don't have doubt about this system's alternator charging hardware or software security.

I am interested in secure solutions for plain and simple systems that make up the majority and I follow the issues related to such systems. This is the common feature of all the discussions I have all initiated. I am talking about the need for direct communication of the alternator regulator and other charging sources' regulators of similar simple systems with the BMS located in the drop-in batteries. This bms is not exist for 12V systems yet. Charging drop-in Lifepo4 batteries by the alternator through a battery isolator which has an LA battery already connected to its other output is my favorite securing method.

[rgleason]

@Solar_Support

Charging drop-in Lifepo4 batteries by the alternator through a battery isolator which has an LA battery already connected to its other output is my favorite securing method.

We are in agreement. I also look forward to the time that Dropin LFP properly communicates it's status to several external alternator regulators and to solar controllers (and even inverters for those who use them).

@Captain Rivet

Use your alternator only for bulk charge till 13.8V and you can never have a problem with the earlier disconnect with aging cells, deviation and a BMS that has 2A active balancers or even Li-time surprise boxes with passive balancer without external communication.

An alternator is the worst efficient charge source on a vessel and using it above 13.8V (or equivalent to 24 or 48V systems) makes 0 sense (for the last 5AH) and just calling for trouble. Keep things simple.
And an LiFePO doesn't have to be fully charged all the time, its actually no problem with good cells not to be in the knee >3.4V for over a month without being out of balance, especially if your bank sees <0.3C charge and discharge which is common in marine use. absolutely no issue doing that....again so much lead thinking...

Solar or shore power charger is perfect for doing the rest, Alternator the worst with major risks for the whole system. And yes charge your surprise boxes without external communication to 3,65V=14.6V (if the manufacturer is not explicitly stating different, then use this...if stated 14.2-14.6V use 14.6V) as the tiny passive balancer needs that time to get or keep it properly balanced and thats your only indication how well your battery is doing...if it shuts of at 14.2V you know you have a problem and its out of balance but you can still rescue it without cutting open...charging to 14.2V you won't realize till too late and balancer has not enough time to do its job properly. That damages the cells more then even keeping it fully charged at 14.6V for weeks. And you don't hurt your battery charging it to 3,65V, it is speced to do that and cycle life is between 2.5V and 3,65V given. Just don't keep it at 3,65V for days or weeks...
Lifepo4, even tested cheap dropin or ok DIY build banks with a well tested BMS are much more reliable, totally maintenance free and much more constant over time then any lead can ever be.
Stay to basic rules and keep it simple and you have a trouble free battery.

If you have full communication from BMS, real experience (not from watching 20 youtube videos, yes they help but cannot replace experience) and access to cells you can optimize that to 3,45-3.6V as you can always correct it if you see you get a runner...but if you are in the dark don't try to do it, you will create more damage then optimizing can ever do good. Experience dealing with lithium for 20 years and paid my lessons....Amen
If you have full communication from BMS, real experience (not from watching 20 youtube videos, yes they help but cannot replace experience) and access to cells you can optimize that to 3,45-3.6V as you can always correct it if you see you get a runner...but if you are in the dark don't try to do it, you will create more damage then optimzing can ever do good. Experience dealing with lithium for 20 years and paid my lessons....Amen

Thank you. This is very condensed and useful information that should be considered. Also the overall system has to be designed to protect the alternator and regulator from load dumps. The Victron Argofet is a good answer.

[rgleason]

Epoch keeps taunting. 120ah deep cycle & starter battery with comms $799 (2) in parallel or (3) in parallel would work well, and also protect the alternator in the case where one of the battery's BMS shuts off, provided the alternator is not charging at greater than 100a.

Capt. Rivet advises that it is more effective to simply get a 300ah LFP, and I would then certainly use a Victron 200a Argofe Battery Isolator, (I would also use it in any case) to provide Alternator load dump protection. See the Victron wiring Diagram on the second page.

It would be ideal if Epoch batteries with comms, actually directed the smart regulator (Zeus or Wakespeed), but that has has not been confirmed yet. So at this point a Balmar regulator is a perfectly reasonable choice. and then set the Balmar to the setpoints and parameters that Epoch requires. I would also use a Balmar APM-12 at the alternator as a secondary backup load dump protection.

Then I understand that you will need to monitor the individual cells and make sure to balance charge to above SOC 96%-98% occasionally, to offset any differential cell voltages and individual cell state of charge, which is a manual monitoring operation using the handy Bluetooth App. This process will be helped by the 2a active balancing in the Epoch battery.

100-200 watts of solar with a Victron MPPT should provide the 3-5 amps required to balance these batteries over several days, provided the MPPT are set properly and the boat is unoccupied on a mooring or at the dock, once or twice a month, without any loads.

I think I would be comfortable with this system, but I have not experienced it yet.

The one question I have for Epoch, is if the Bluetooth App has an advanced BMS shutdown alarm to meet ABYC requirements.

From the User Manual for this Epoch Battery:

User can use an external communicated cable (optional) to connect to batteries and other device via
CAN bus. This allows for communication between the battery and the load or charger, making it
more efficient to use the battery. This is also beneficial for understanding battery faults. If you have
more questions about the CAN bus, please contact Epoch for technical support.
For normal battery operation, the CAN bus function is not mandatory. The battery can automatically
operate and protect itself; it does not require any CAN bus communication or external devices (such
as external controllers) or other CAN bus connected batteries to operate. Retain the two black covers
installed on the two M12 connectors to protect them from environmental influences when

[SOLAR SUPPORT]

I think Epoch battery has a BMS that works based on CAN bus data communication. Leave aside the CAN bus data communication compatibility issues of various brands. How can an advanced marine battery BMS like Epoch provide the HVC, LTC, HTC, HCC outage pre-warning required for a simple installation that does not use CAN bus?

These uncontrollable outages pose a threat to the alternator that does not have proper Can bus communication with BMS. Epoch's recommendation for a 2p or 3p installation does not close this gap. Using an ArgoFET battery isolator to eliminate alternator high voltage dump damage risks of the uncontrolled drop-in bms cutoff is the only sustainable and secure way. An LA battery must be connected to one of the battery isolator's output to manage system's security risks which does not has a properly working Can bus communication.

You can watch Andy's JK inverter bms visual, the video link of which I gave in previous posts. JK inverter bms manufacturer made a way to communicate with the charging devices for 8s and 16s battery by adding two external relay switches that can be controlled by User adjustable cell parameters, but; We don't know if there is any initiative for 4s.

Drop-in LI battery and, above all, alternator, ac, solar, inverter, wind and generator charger manufacturers need to work together to understand the need to prevent independent control of drop-in BMS and then consider a proper way to eliminate this. That's what has to happen eventually. When it will happen depends on the opening of perceptions.


About CAN bus

https://www.ni.com/en/shop/seamlessl...EaAtrjEALw_wcB

[rslifkin]

In a simple setup without CANbus or other methods of getting data from something like the Epoch BMS, the simplest thing in my mind is to keep a lead acid starter battery for the engine and depending on alternator size, either use an Argofet (as mentioned above) or a DC-DC charger to handle getting power from the alternator to the LFP bank.

Having a FLA or AGM battery for engine start isn't a big deal, as a good one should have a very long lifespan in that usage where it's kept fully charged pretty much all the time. The AGM starter batteries on my engines are currently 6 years old and still doing the job just fine, for example.

[MV Intrigue]

Originally Posted by rgleason

The one question I have for Epoch, is if the Bluetooth App has an advanced BMS shutdown alarm to meet ABYC requirements.

From the User Manual for this Epoch Battery:

The ABYC standard for pre-warning is really not clear and IMO is not grounded in reality. From my discussion with several people, the reason it was relegated to a recommendation for prewarning is because it is actually impossible to give prewarning in all cases of impending shutdown. Low voltage...that's easy. Short circuit protection...impossible.

As for the Epoch 460s it has several kinds of warnings, especially when coupled to a Cerbo GX that can display prewarnings.

1) the tethered monitor will sound a warning at 20% as well as 10% SOC. They self cancel after a minute or two.
2) the app will will display 2 dozen warnings. None are prewarnings that i know about.
3) Cerbo/Multiplus will sound prewarnings for low voltage that are also prewarnings as well as prewarnings you can set such as SOC%. I believe these can be set in Cerbo to use either Victron shunt or the Epoch comms if you set "batt monitor" in Cerbo to Epoch. But I would have to do more testing to confirm.

Warnings for high voltage, cell over volt and other warnings associated at the top of the charge AFAIK do not have prewarnings. But they also will not shut the entire battery down, just the charge mosfets. Of course this leads to the conditions of voltage spikes when charging with the alternator unless the system is configured for protection in the various ways. One way to prevent that is to limit charge voltage in the DVCC to what works. Epoch lists 14.6 volts as maximum charge voltage. but I think people confuse that with how a system should be set up for repeated charging in a boat, camper or off grid system. I dont know of any such system that is actually successful charging to 14.6. Its just way too high. 13.8 to 14.2 is probably best. Balancing will still work fine even with a max charge voltage of 13.8. Cell balancing in the 460 is initiated at cell voltage above 3.35 (~13.4v with a deviation of .050). Also from what I have seen myself and researched cell balance tends to be worse above 14.2 in nearly all lifepo4 batteries and capacity does not increase above 14.2 in any meaningful way. I will probably end up using 14.0 as set in the DVCC as max charge voltage. That allows for 99.8 % capacity, decent charge time, plenty of room to prevent nuisance overvolt trips that may shut down the charge mosfets, and is generally much more stable with the Victron comms.

The overvolt parameters that typically cause the condition that disconnects the charge mosfets is anything over 14 volts and charge current falling below 3.5 amps for more than 10 seconds. Keep in mind this is an Epoch primary protection as part of the BMS programming and not part of the Victron protocol communicated from the Epoch to the Cerbo. So if one sets the upper charge limit to 13.8 or 13.9 it should stay clear of this condition that may shut down the charge mosfets.

Below is a link to some Epoch 460ah bench testing. There are a few other videos as well on the channel.

https://youtu.be/oUcjefQ8TAU?si=GN9T1NC7rIex4djk

[SOLAR SUPPORT]

Originally Posted by MV Intrigue

The ABYC standard for pre-warning is really not clear and IMO is not grounded in reality. From my discussion with several people, the reason it was relegated to a recommendation for prewarning is because it is actually impossible to give prewarning in all cases of impending shutdown. Low voltage...that's easy. Short circuit protection...impossible.

As for the Epoch 460s it has several kinds of warnings, especially when coupled to a Cerbo GX that can display prewarnings.

1) the tethered monitor will sound a warning at 20% as well as 10% SOC. They self cancel after a minute or two.
2) the app will will display 2 dozen warnings. None are prewarnings that i know about.
3) Cerbo/Multiplus will sound prewarnings for low voltage that are also prewarnings as well as prewarnings you can set such as SOC%. I believe these can be set in Cerbo to use either Victron shunt or the Epoch comms if you set "batt monitor" in Cerbo to Epoch. But I would have to do more testing to confirm.

It is a very good feature that Epoch sends battery data via Can bus data communication. In the future, the Can Bus Bluetooth bus can be created wirelessly. I don't know if there are studies on this subject. In this way, unnecessary cable clutter and problems with incompatible plugs would be eliminated.

Since it is the BMS that isolates the battery in order to protect the cells and itself, the BMS itself must make the decision to trigger this action. I don't understand why it can't give a warning signal right before this. A voice warning given long before this decision is of little use. It must be included in ABYC Standards, but; It is not enough. Imagine that the engine is running, it is almost impossible to hear this warning signal. As for the JK BMS: when the voltage of any cell is 3.6V, it can be set to operate the relay on it for preliminary warning before the BMS triggers the battery isolation. This is exactly what the physical pre-warning signal bms is supposed to do.

It is obvious that there is a problem with the load distribution of the parallel Epoch 460 batteries you connected to the test set. Did you find the reason? Connecting the thick energy cables coming from the batteries in parallel connection in a Y or T shape may give better results. Similar to this experimental set, two 200Ah Lifepo4 batteries are connected in parallel on my boat. In this setup, the batteries are connected directly to the inverter. As a result of the clamp ammeter measurements I made separately from the terminals of both batteries during a total discharge of 100A, I observed that the load distribution was much more stable. Towards the end of the video, when the capacity of the Epoch batteries is 0%Soc, I can only make a guess for the strangeness seen in the measured current values ​​when the fan is running. At this time, an active or passive balancer, if any, may have been activated.

[CaptainRivet]

Originally Posted by MV Intrigue

The ABYC standard for pre-warning is really not clear and IMO is not grounded in reality. From my discussion with several people, the reason it was relegated to a recommendation for prewarning is because it is actually impossible to give prewarning in all cases of impending shutdown. Low voltage...that's easy. Short circuit protection...impossible.

As for the Epoch 460s it has several kinds of warnings, especially when coupled to a Cerbo GX that can display prewarnings.

1) the tethered monitor will sound a warning at 20% as well as 10% SOC. They self cancel after a minute or two.
2) the app will will display 2 dozen warnings. None are prewarnings that i know about.
3) Cerbo/Multiplus will sound prewarnings for low voltage that are also prewarnings as well as prewarnings you can set such as SOC%. I believe these can be set in Cerbo to use either Victron shunt or the Epoch comms if you set "batt monitor" in Cerbo to Epoch. But I would have to do more testing to confirm.

Warnings for high voltage, cell over volt and other warnings associated at the top of the charge AFAIK do not have prewarnings. But they also will not shut the entire battery down, just the charge mosfets. Of course this leads to the conditions of voltage spikes when charging with the alternator unless the system is configured for protection in the various ways. One way to prevent that is to limit charge voltage in the DVCC to what works. Epoch lists 14.6 volts as maximum charge voltage. but I think people confuse that with how a system should be set up for repeated charging in a boat, camper or off grid system. I dont know of any such system that is actually successful charging to 14.6. Its just way too high. 13.8 to 14.2 is probably best. Balancing will still work fine even with a max charge voltage of 13.8. Cell balancing in the 460 is initiated at cell voltage above 3.35 (~13.4v with a deviation of .050). Also from what I have seen myself and researched cell balance tends to be worse above 14.2 in nearly all lifepo4 batteries and capacity does not increase above 14.2 in any meaningful way. I will probably end up using 14.0 as set in the DVCC as max charge voltage. That allows for 99.8 % capacity, decent charge time, plenty of room to prevent nuisance overvolt trips that may shut down the charge mosfets, and is generally much more stable with the Victron comms.

The overvolt parameters that typically cause the condition that disconnects the charge mosfets is anything over 14 volts and charge current falling below 3.5 amps for more than 10 seconds. Keep in mind this is an Epoch primary protection as part of the BMS programming and not part of the Victron protocol communicated from the Epoch to the Cerbo. So if one sets the upper charge limit to 13.8 or 13.9 it should stay clear of this condition that may shut down the charge mosfets.

Below is a link to some Epoch 460ah bench testing. There are a few other videos as well on the channel.

https://youtu.be/oUcjefQ8TAU?si=GN9T1NC7rIex4djk

Simple answer if manufacturer tells you to charge to 14.6V, charge to 14.6V as they tested that.
The amount of people think they do and know better then manufacturer out there is huge and the hokuspokus that 3,45 or 3,55V enlarges lifespan a lot. Fact is cells are speced to charge to 3,65V and the 3 major factor of depreciation is age, age, C-rate charged and discharged. The pontntial that you harm a battery when charging too low and not get enough time for too balance is much higher then the lifespan gain to charge to 3,55V.
BUT don't leave it charged at 3,65V and if possible cycle between 50 and 80%DOD with max 0.3C charge or discharge, that give you max cycles.