Problem with Balmar Mc614 and LiFeP04

[ksanders]

i am having a bit of a problem with my Balmar MC-614 alternator and my LiFeP04 batteries.

The symptom is that when the engine is first turned on the alternator ramps up to 100% SOC on the batteries.

Then the SOC starts dropping and I do not know how far it will drop, I get worried and fire up the generator. One timeI let it continue to go down to 77% before turning on the generator.

This phenomenon does not happen when on AC power and the Victron multiplus is operating.

The MC-614 is set to the default LiFeP04 settings

Attached are the default MC-614 settings, and a graph showing my SOC. You can see where I started the engines on the left, we got a good initial charge, and then the SOC started going down.

Also is a graph showing my currents and voltages on the system.

Any clue what the fix is?

The only thing i can see s that the float voltage is set a bit lower than the victron gear at 13.4 volts vs the victron I am setting at 13.5

It's not a voltage sensing issue as the balmar is showing the same voltage as the Victron.

There is something called "calculated float voltage" that seems to come into play using the Balmar, this seems to be to be odd.

What have others done to resolve this using the Balmar regulators?

 

[READY]

Kevin. I have both a Balmar (came withe the XT-170 Balmar alternator) and Wakespeed. I started testing with Balmar but quickly switched to the Wakespeed. While it is $500 it provides so much more diagnostic info and integration with the Victron Cerbo. I was never sure what the Balmar was doing. Plus changing settings with the magnetic was a PITA!

I wish I could shed some light on your issue but this is why I decided to shelve the Balmar. I have it mounted in case of emergency.

Total guess but perhaps the balmar is turning off due to some false temperature sensor reading?
Ken

 

[Insequent]

Missing info is the alternator specs.

Ken's comment on temp is close to the mark I think. In the default LFP profile Kevin posted the strikingly odd parameter to me was Max Alt Temp of 100°C. I have 2 x 200A Leece Neville alts and max temp is 86°C unless there is directed fan cooling of the alts. So, first question for Kevin is do you have cooling for the alt?

Second question is, have you de-rated the alt slightly to avoid it overheating? I have a dual Balmar 612. In the Basic Programming I opted for BL2 (belt load manager) and this has de-rated my alts to about 90%. Even with my old AGM's I was using BL1. Now with LFP's, which can absorb high charge rates for long periods, it is critical not to be asking too much from your alt unless it has very good cooling. The belt load manager works well for doing this.

Yes, the magnetic pad for programming Balmar's has a learning curve and you do need to be focussed and concentrate setting the parameters you want. But once its done you seldom need to revisit it. If you have not read Rod Collin's article it would be worth doing.

Programming a Balmar External Voltage Regulator - Marine How To

Preface This article contains three separate videos that show how to physically program Balmar regulators. The videos are meant to be watched in conjunction with reading this article so the misconceptions and misunderstandings I have identified over the years, regarding these regulators, can be...

marinehowto.com

Make up a "cheat sheet" with your parameters and have at it...

 

[Jeff F]

...Then the SOC starts dropping and I do not know how far it will drop, I get worried and fire up the generator. One time I let it continue to go down to 77% before turning on the generator.

This phenomenon does not happen when on AC power and the Victron multiplus is operating.

Lithium doesn't like to live at 100% SoC, and most charging systems recognize that and essentially allow the battery to cycle.

What you're seeing would be alarming with LA batteries, but looks pretty normal to me for lithium. I suspect that bumping the float to 13.5 would call for somewhat earlier interruption of the decline.

I have an MC-614 and dialed back the voltages and (probably too much) other stuff so it charges to about 90% SoC on startup and basically sits idle down to below 50% SoC, then sort of floats there. In my case I wanted to leave lots of buffer to take advantage of solar.

I guess I don't see this phenomenon as a regulation issue, but as a product of the change in battery chemistry. Care and feeding is a little different.

 

[DDW]

SOC has way too much stuff smashed together in it to diagnose much. What is needed is a graph of voltage and amps at the battery. The 614 is very poor at guessing when to restart absorb from float and when to go into float. Do you have the Victron shunt? Can you produce a graph of voltage and amperage (into the battery) on a charge cycle?

 

[Bmarler]

So, the graph looks like soc over about a 14 hour span. Was the engine running this whole time? We can’t see the actual battery voltage, just the soc. We don’t know if it’s dropping into float because we can’t see the voltage.
I don’t run lithium yet, so I’m not sure what the best setup is, but…
Running a balmar regulator at the canned settings won’t really take advantage of its capacity. Balmar put out a service bulletin in 2017 that said if your regulator was earlier, the stock lithium program won’t work well. you should use the advanced menu and change the bulk/absorb/float voltages to something like 14.2/14.1/14.0. ( depending on the battery manufacturer specific requirements.)
Setting with the reed switch leaves a little to be desired, but it works.
Further, if you already have a balmar, you might want to consider moving to a 618 and get a Bluetooth adapter for it. This gives you access to everything you need to get the most out of it right on your phone. No reed switch to mess with, access to every parameter. Plus, the display mode shows the charge stage, field output, voltage, everything you’d want.

 

[Don L]

You should connect Balmar!!!!!! These can and do go bad. maybe try doing the factory reset first.

 

[Jeff F]

Running a balmar regulator at the canned settings won’t really take advantage of its capacity. Balmar put out a service bulletin in 2017 that said if your regulator was earlier, the stock lithium program won’t work well. you should use the advanced menu and change the bulk/absorb/float voltages to something like 14.2/14.1/14.0. ( depending on the battery manufacturer specific requirements.)
Setting with the reed switch leaves a little to be desired, but it works.

I can see how raising the float value would cause the regulator to resume charging at a higher SoC. But I question the wisdom of doing this.

It's pretty well established that keeping LI batteries at > 80% SoC isn't optimal for battery health. I use my boat daily, and so deliberately chose settings for my charge sources to allow my batteries to live in that optimal 20-80% SoC most of the time with occasional charges to 100% with solar to maintain cell balance. If for some reason I want to be at full charge when stopping I'll manually kick off a full charge before stopping, but that's extremely rare. If I'm anchoring for one night I know that I have lots of power to get me through the night at > 30% SoC. That's a function of capacity vs use, but there is no harm in utilizing the bottom end of capacity with LI.

I think that the notion of keeping the batteries at 100% SoC is an artifact of how we thought about LA batteries, and should be avoided with LI.

 

[twistedtree]

The SOC is dropping because your float voltage equals an SOC in the 70% range. That’s a good float voltage for sitting at a dock for days on end, but it’s not a good voltage or SOC for arriving at an anchorage. To deal with just this, I have my alternator float, and only the alternator float, set a bit higher. 13.5V works to hold my batteries at 100% SOC with zero amps going back into the batteries. That part is really important. You don’t want ongoing charge current after you reach 100%.

You may need to play with the float voltage to see what works. Also, charting battery voltage on that graph should show more of what’s going on, and might provide further guidance.

 

[Jeff F]

The SOC is dropping because your float voltage equals an SOC in the 70% range. That’s a good float voltage for sitting at a dock for days on end, but it’s not a good voltage or SOC for arriving at an anchorage.

...or motoring for days on end.

 

[Jeff F]

...13.5V works to hold my batteries at 100% SOC with zero amps going back into the batteries. That part is really important. You don’t want ongoing charge current after you reach 100%.

Probably a sidebar, but I understand from some of your previous posts that you use conservative voltage thresholds for charging.

Is it possible that your 100% metric might differ from a typical drop-in pack using mfg guidance? It's been a while, but my recollection with my batteries is that 13.5v float on any of my charging sources would allow discharge down to mid 80s SoC. But that's with a 14.6v bulk V.

 

[Bmarler]

The voltages I posted were on the service bulletin from balmar, and we’re also posted with recommendation to check your battery manufacturer recommendations for volt thresholds.
I don’t run lithium, but I do use balmar and understand how they work. Using the advanced menu is the best way to go.

 

[ksanders]

Thanks for all the help!!!

Yesterday I changed the "stock" parameters in the Balmar regulator a bit... Some were left unchanged.

Bulk voltage 14.2
Absorption voltage 14.2 basically eliminating the absorption phase
float voltage 13.5
float voltage timer 6 hours which is the max

I have been making way for 10 hours as of right now, and have another 34 left to go, so we will see how this works.

For the first maybe three hours the alternator was outputting 110 amps approx divided between the batteries and loads. Then the batteries were at 100%.

But... the solar keeps the batteries full and the sun just went down a couple hours ago.

We'll see how this works overnight, and I'll post again in the morning.

BTW we are heading north up the Baja and are making the final run into ensenada right now running continuous till we get there in again 34 hours approx.

This is a start of a three year exploration of the pacific coast to Alaska and returning fall 2027 to La Paz where we retained our slip.

Here are some screen shots. I have a soc meter on victron vrm and I have an alternator shunt but it is not connected to my cerbo as I did not have time to get the cables delivered to la paz before we left.

In also have a new Argo Zeus regulator that I need to get installed, but again didnt have time.
Right in the middle of my house/life/boat prep 4 weeks ago I fell and dislocated my shoulder setting me back a bit. Fortunately it healed rapidly but...

 

[twistedtree]

...or motoring for days on end.

Yes, but how often does that happen, and for how long? And worst case you could dial down the float voltage for the duration.

 

[twistedtree]

Probably a sidebar, but I understand from some of your previous posts that you use conservative voltage thresholds for charging.

Is it possible that your 100% metric might differ from a typical drop-in pack using mfg guidance? It's been a while, but my recollection with my batteries is that 13.5v float on any of my charging sources would allow discharge down to mid 80s SoC. But that's with a 14.6v bulk V.

Possibly. My MG BMS charges up to 3.5 vpc. But SOC calculations I think are predominantly based on Ah counting. So once at 100% SOC, it won't change just by lowering the voltage, only of you draw Ahs. I don't recall exactly what I have my Wakespeed set to, but bulk is roughly 27.6 (3.45 vpc), and that takes SOC up to 95% or so. Then it floats at 27.0V (3.375vpc) for the duration of the run. With that, SOC slowly climbs the rest of the way to 100%. This approach works well for me and results in 100% SOC when I drop anchor. Values probably have to be adjusted for other systems, but I think the approach works well.

As for the specific numbers, with the exception of the Wakespeed, my batteries+BMS decide that the charge voltages are, not me. I think bulk ends up being 3.5 vpc, and float 3.4vpc, so a bit higher than I used on my first system where I controlled everything, but not by much. I'm frankly very surprised by how high some batteries say to charge. 3.65 vpc is the outer limit for LFP cells, and many say 3.6 vpc. With so little incremental stored energy between charging to 3.5vpc and 3.6vpc, I just don't see much value is pushing it. Plus, you are so close to the edge that the slightest imbalance in cells should cause a disconnect. If you only charge to 3.5 vpc, there is a lot more leeway.

 

[ksanders]

Here is what happened overnight..

It looks like the system is functioning as designed, but not how I want it to work.

I'll get the Arco Zeus regulator installed in ensenada so that I can run my batteries up and leave them there.

 

[guy with a boat]

Kevin, your float voltage is set at 13.5v and your graph shows float voltage at 13.3 or a little less. Could you be losing .2v between the alternator and batts? I think I would put a multimeter on the alternator output and on the batts and see if both numbers are accurate.
As you say, the Balmar is acting correctly, its just not providing voltage at the batteries that is what you intend. The problem is likely not the regulator output or alternator behaviour. Seems like it may be a voltage drop issue or just inaccurate readings at one point or the other.
I’ll let the experts handle this, but that’s the path I would be following if it were mine.

 

[SteveK]

Kevin, do you have a re-bulk voltage setting on that regulator? It seems to be working like my Magnum inverter/charger. Once 100% SOC is reached it will float 13.5v and current only flows for light loads. Heavier loads draw down SOC until 12.8v is reached before bulk charging starts again. With LFP that takes longer to occur.

 

[ksanders]

Kevin, your float voltage is set at 13.5v and your graph shows float voltage at 13.3 or a little less. Could you be losing .2v between the alternator and batts? I think I would put a multimeter on the alternator output and on the batts and see if both numbers are accurate.
As you say, the Balmar is acting correctly, its just not providing voltage at the batteries that is what you intend. The problem is likely not the regulator output or alternator behaviour. Seems like it may be a voltage drop issue or just inaccurate readings at one point or the other.
I’ll let the experts handle this, but that’s the path I would be following if it were mine.

No voltage loss. My shunt/voltmeter on the alternator and my shunt/voltmeter on the batteries are real close.

This issue is I am 100% sure now is related to the Balmar regulator intentionally dropping the float voltage into "calculated float" (yes it says that in the balmar manual and I have zero clue why) .

I cannot graph properly my alternator shunt/voltmeter over time because that device a BMV712 is not connected to the cerbo because I don't have a VE direct cable yet.

I am not at all pleased with the idea that the balmar regulator has a "calculated float" I like the idea of I tell it the float and it stays there.

My opinion the balmar is making decisions about cycling the batteries because I chose Lithium as a base profile, and then modified it. I am willing to bet that if I chose FLA as a base profile and modified that to 14.2 bulk, 14.2 absorbtion, and 13.5 float this would not be happening.

 

[ksanders]

Kevin, do you have a re-bulk voltage setting on that regulator? It seems to be working like my Magnum inverter/charger. Once 100% SOC is reached it will float 13.5v and current only flows for light loads. Heavier loads draw down SOC until 12.8v is reached before bulk charging starts again. With LFP that takes longer to occur.

Yes that is what is happening!

But... there seems to be no setting in the balmar to disable that function.
but... it did not happen when I had a FLA battery bank and was using a modified FLA baseprofile.

 

[Jeff F]

Here is what happened overnight..

Did you do something to kick off the second charge cycle, or was that done by the regulator?

 

[ksanders]

Did you do something to kick off the second charge cycle, or was that done by the regulator?

it did it all by itself.

 

[mvweebles]

Kevin - as you know, my knowledge on stuff like this isn't great. But have you checked for voltage loss on your negative cable? Not even sure this makes sense - I know you're a top notch electrician and I'm not knowledgeable enough to follow this thread but thought I'd throw it out there. I had a sensing issue with my Balmar that I was sure was due to some sort of erroneous setting or malfunction with the balmar. Turns out there was a meaningful voltage drop on the negative cable because the guys who installed the DC cables ran the negative 30-feet to the main panel instead of 6-feet to a negative bus bar next to the batteries. Also has a lousy crimp where the heat shrink jacket impeded the connection. Balmar was happily picking voltage off the positive conductor but could not see/compensate for the drop in negative side of the run.

Hopefully this isn't a distraction.

Peter

 

[ksanders]

Kevin - as you know, my knowledge on stuff like this isn't great. But have you checked for voltage loss on your negative cable? Not even sure this makes sense - I know you're a top notch electrician and I'm not knowledgeable enough to follow this thread but thought I'd throw it out there. I had a sensing issue with my Balmar that I was sure was due to some sort of erroneous setting or malfunction with the balmar. Turns out there was a meaningful voltage drop on the negative cable because the guys who installed the DC cables ran the negative 30-feet to the main panel instead of 6-feet to a negative bus bar next to the batteries. Also has a lousy crimp where the heat shrink jacket impeded the connection. Balmar was happily picking voltage off the positive conductor but could not see/compensate for the drop in negative side of the run.

Hopefully this isn't a distraction.

Peter

Not a distraction at all peter.

when i was going through the configuration day before yesterday of the Balmar I verified that the Balmar was reading the same as the Victron shunt.

 

[Jeff F]

it did it all by itself.

Gotcha. I wouldn't change a thing. Your graph indicates that when you stop your SoC will be somewhere between 90-100% depending on where in the cycle you stop.

I think you'll see similar behavior with the Multiplus and other charging sources. Being plugged in at dockside doesn't mean the battery is going to be at 100% when you unplug.

I should say that I've spent a few hundred days underway watching voltage and amperage on my LiFePo house bank. My advice is that it's mostly a distraction. Voltage on its own doesn't tell you much in the working range of the battery, and varies according to where measured and how much current is flowing. That's why all the systems use fancy algorithms to guestimate the net charge.

 

[NoRain]

Kevin, do you have the Positive Voltage Sense (terminal 9 on your 614 regulator) connected *directly to the battery*?

 

[ksanders]

Kevin, do you have the Positive Voltage Sense (terminal 9 on your 614 regulator) connected *directly to the battery*?

Yes I do

 

[ksanders]

Here are graphs of my battery voltage, and my SOC for the last 24 hours. We have been underway the whole time and have not used the generator.

From what I am seeing, this cycling is pretty clearly intentional. It appears to be part of the LiFeP04 base algorithm in the MC-614 regulator.

I have had this same regulator, but programmed for my old FLA batteries and been underway for 24 hour stretches at a time and can tell you this behavior is different. Before LiFeP04 batteries the regulator would charge to 100% SOC and stay there forever.

So... I'm going to put this down to a intentional design parameter and not worry too much more about it.

Once I make it back to America in the next month or so I'll tie my alternator monitoring shunt into my CERBO and see how that works out. I'll also install the new Argo Zeus regulator and play with that. I'll connect it to the cerbo and see how the display reacts. I like the idea of a voltage regulator that can be configured using my phone, so this will be fun.

BTW we are nearing the end of our trip up the Baja, and will be happially at Baja Naval in Ensenada sometime tonight, to get bottom paint, and a few other projects completed.

 

[Jeff F]

Yes, but how often does that happen, and for how long? And worst case you could dial down the float voltage for the duration.

I'd turn the question around... What requirement is there to be at > 80% SoC when the motor shuts down?

For those who cruise between slips and plug in regularly, or use solar and/or genset, or aren't going to fully discharge the battery when they stop this isn't a requirement. Burning more fuel to charge and keep the battery at a higher SoC range in this case seems unproductive to me. Use case matters when making these fine tuning adjustments.

I can appreciate your rationale, but IMO for many people there is a good argument for keeping the regulator values on the low side.

 

[twistedtree]

I'd turn the question around... What requirement is there to be at > 80% SoC when the motor shuts down?

For those who cruise between slips and plug in regularly, or use solar and/or genset, or aren't going to fully discharge the battery when they stop this isn't a requirement. Burning more fuel to charge and keep the battery at a higher SoC range in this case seems unproductive to me. Use case matters when making these fine tuning adjustments.

I can appreciate your rationale, but IMO for many people there is a good argument for keeping the regulator values on the low side.

Oh, none other than preference and cruising habits. I anchor way more than I dock, so more often than not I am arriving at an anchorage, so having batteries topped up is desirable. When I instead arrive at a dock, by quattro float is lower and for the first several hours I'm plugged in the batteries are carrying to load while their voltage drops down to the quattro float voltage.

If you are usually returning to a dock with power, then a lower alternator float may make more sense.