Balmar SG200 SOC Meter

[Codger2]

I also have issues with my SG200. Part of the issue seems to be that the SG200 is not all that happy with smaller battery banks........


So I don't really trust the SG200 to give me an accurate SOC.

So far the only reason I don't take it out completely is that the display is SOOOO much easier to read (It sure is!)than the on the Victron 602 .

Having had an SG200 recently installed and having read the instructions (excellent!) 5 or 6 times, I, too, am frustrated over how long it takes to discharge my 16-6 volt golf cart bank down to 37% SOC. In the process of investigating all facets of the gauge, I inadvertently screwed up my "time to go" display. So, I selected the "factory reset" function (mistake) instead of the "network reset"! I am now starting over the process of obtaining SOH information. What confuses me, however, is that the instructions only refer to the drastic discharging process as a "short cut" to attaining SOH values. Am I to assume if I do nothing other than continuing to recharge to full after each outing the SOH value will eventually appear?

 

[Prospective]

Just noticed there's a firmware update released 4/20/21. Mentions improvements to SOC when batteries are kept on float as well some SOH enhancements.

https://balmar.net/sg200-upgrades/

 

[DDW]

For a device that claims not to require any calibration, it sounds like there is a lot of calibration required. I can set up something like a Victron BMV in about 5 minutes and it will be very close - good enough for almost any use.

The comment above about the alternator cycling due to temperature rise - what regulator do you have? A Balmar 614 derates progressively for temperature and has a servo capture loop, it will quickly stabilize in temperature and there will be no cycling. Perhaps something else is amiss?

 

[Prospective]

For a device that claims not to require any calibration, it sounds like there is a lot of calibration required. I can set up something like a Victron BMV in about 5 minutes and it will be very close - good enough for almost any use.

The comment above about the alternator cycling due to temperature rise - what regulator do you have? A Balmar 614 derates progressively for temperature and has a servo capture loop, it will quickly stabilize in temperature and there will be no cycling. Perhaps something else is amiss?

You're not wrong. A traditional battery monitor would required very little set-up. Actually the set-up of this device isn't that complicated either. Choose battery chemistry, set Amp hour capacity, that's pretty much it.

The "calibration" is really just the device "learning" your system to, in theory, provide more accurate info on SOC and SOH that traditional monitors can run into trouble with.

But the more I struggle with it and hear from other users and the likes of Rod Collins, the parameters of the calibration, and requirement for multiple deep discharges and recharges is a hassle. It's not easy, unless you live on your boat, to arrange for the banks to be run down to < 50% SOC and brought back to 100% successively over multiple occasions.

The original marketing was that it will "learn your system and bank over time". But if that learning has to take place in a very specific fashion it becomes a challenge. My boat has been on the hard since last fall. I feel like I'll be essentially staring from scratch with the "learning".

 

[Codger2]

Choose battery chemistry, set Amp hour capacity, that's pretty much it. (In fact, that is all you have to do to get the device going!)

The original marketing was that it will "learn your system and bank over time". But if that learning has to take place in a very specific fashion it becomes a challenge..

I started mine by selecting the chemistry (AGM & the amps (446) I immediately got SOC, amps in & out, time to go and volts. I have yet to see SOH numbers.

 

[catalinajack]

The marketing is clearly misleading in terms of getting to SOH. But, as a coulomb counter it is terrific out of the box. I will, as everyone must be, be patient for the SOH to appear. Not happy with this aspect but, if it works, eventually, this feature should prove to be valuable. Since we generally keep our batteries at least five years and often much longer, the SOH feature will be quite helpful in telling us when it is time to replace. We'll see what we see.

You're not wrong. A traditional battery monitor would required very little set-up. Actually the set-up of this device isn't that complicated either. Choose battery chemistry, set Amp hour capacity, that's pretty much it.

The "calibration" is really just the device "learning" your system to, in theory, provide more accurate info on SOC and SOH that traditional monitors can run into trouble with.

But the more I struggle with it and hear from other users and the likes of Rod Collins, the parameters of the calibration, and requirement for multiple deep discharges and recharges is a hassle. It's not easy, unless you live on your boat, to arrange for the banks to be run down to < 50% SOC and brought back to 100% successively over multiple occasions.

The original marketing was that it will "learn your system and bank over time". But if that learning has to take place in a very specific fashion it becomes a challenge. My boat has been on the hard since last fall. I feel like I'll be essentially staring from scratch with the "learning".

 

[Codger2]

I will, as everyone must be, be patient for the SOH to appear. Not happy with this aspect but, if it works, eventually, this feature should prove to be valuable.

My thoughts, exactly! I am going to discharge, however, my 16-6 volt bank as directed, down to 37% or less and see what happens. The photos below were taken with shore power on & everything else off. With the exception of "having to wait for the SOH to appear", I really love the easy to read & intuitiveness of this monitor.

 

[sbman]

I started mine by selecting the chemistry (AGM & the amps (446) I immediately got SOC, amps in & out, time to go and volts. I have yet to see SOH numbers.

I think the issue for some is that the SOC is related to the device's interpretation of the SOH. On a traditional monitor, you can often set the puekert factor which adjusts for discharge/efficiency curves based on load level. With the Balmar, it's supposed to figure this out on it's own, as well as automatically figuring out the level of capacity degradation that the bank has experienced and automatically provide an accurate SOC. If it isn't making these adjustments correctly then it is providing invalid SOC data.

I've got a Victron BMV-712 and I'm considering running one of these Balmar as well to see how they compare, so I'm interested in hearing more on people's experiences.

 

[Prospective]

I think the issue for some is that the SOC is related to the device's interpretation of the SOH. On a traditional monitor, you can often set the puekert factor which adjusts for discharge/efficiency curves based on load level. With the Balmar, it's supposed to figure this out on it's own, as well as automatically figuring out the level of capacity degradation that the bank has experienced and automatically provide an accurate SOC. If it isn't making these adjustments correctly then it is providing invalid SOC data.

I've got a Victron BMV-712 and I'm considering running one of these Balmar as well to see how they compare, so I'm interested in hearing more on people's experiences.

This is my understanding as well. The SOC is NOT a simple columb counter. It is supposed to overcome the problems with those devices as battery health degrades. The SOC% is not based on the a simple amp/hr count vs rated battery bank capacity but rather the SOC% is based on the actual capacity of the bank at it's current state of health. If it's working properly then it's a significant improvement over traditional battery monitors. But, as I pointed out earlier, I have come to distrust the results of mine.

 

[catalinajack]

Having acknowledged that the SG200 is not a simple coulomb counter I do not understand why you do not trust the number. However, your post prompted me to further play with mine. I reset the SG200 to factory settings and set about "conditioning" it with six deep discharges. The first time around I did this I was doubting the SOH number I was getting, 100%. My doubt was based on the fact that my batteries are 3.5 years old. But then I remembered that flooded lead acid batteries need as many as 50 deep discharges before they reach their rated potential and then decrease in capacity GRADUALLY from there. Given that I have about 60 deep discharges I am no longer doubting the SOH number. My batteries are at or very near 100% SOH.

As for the SOC, this is what I observed overnight disconnected from shore power. I do have a coulomb counter that reports the number of amphours extracted and the percentage of discharge. The counter reports the percentage in simple arithmetic based on the nominal battery capacity. The percentage reported is accurate. Simple? Straightforward? Yes and no.

What the coulomb counter does no do is to take into consideration the Peukert Factor. As I understand the science, the more and faster a battery is discharged, the real remaining capacity is decreased. That means that the SOC percentage reported by my coulomb counter is too high. The SG200 accounts for these variables, load and Peukert factor, constantly through its high sampling rate and algorithms but, still, I wondered if this would prove true with the SG200. I monitored both my counter and the SG200 as the batteries were drawn down. Early in the drawdown period, the SOC matched on both units. However, when the SOC on the counter approached 70%, the SOC on the SG200 showed 2% lower. By the time the SG200 showed 50%, the counter showed 58% remaining. Why? I firmly believe the SG200, with its sophisticated and no doubt well-tested algorithms, delivers a far more accurate SOC. It also means that if one is relying on simple coulomb counting, you are probably discharging your batteries more deeply than you think. Stated another way, the remaining capacity is lower.

Bottom line for me is that I will rely on the SG200 to monitor SOC. It will take some time to see if SOH begins to decrease. As for trusting Balmar's algorithms I have no trouble doing so. These folks would have done extensive testing to ensure that their product reported accurate results. The SG200 is nothing more than a coded computer that uses huge amounts of data sampling to make its calculations. A coulomb counter uses simple arithmetic with few sampling points.

This is my understanding as well. The SOC is NOT a simple columb counter. It is supposed to overcome the problems with those devices as battery health degrades. The SOC% is not based on the a simple amp/hr count vs rated battery bank capacity but rather the SOC% is based on the actual capacity of the bank at it's current state of health. If it's working properly then it's a significant improvement over traditional battery monitors. But, as I pointed out earlier, I have come to distrust the results of mine.

 

[Prospective]

Having acknowledged that the SG200 is not a simple coulomb counter I do not understand why you do not trust the number. ....

This was my response to you in post #9 as to the reason I've come to not trust the SOC number...

"As to what's leading me to believe there's an issue... I am using the SG200 it's self. It indicates an SOC after a night on the mooring of let's say 86%. But voltage is down to maybe 12.1V on minimal to no load suggesting a much lower SOC. This voltage is confirmed by a separate blue seas voltmeter in the battery compartment. But I know voltage as an indicator of SOC can be misleading...So I run my single cup coffee maker via my Victron 2000W inverter/charger and it shows a low voltage error. I don't believe it would do this if my 300amp/hr FLA bank was actually at 86%. Perhaps I misinterpreting the data? But I've shared this info with Balmar and they haven't suggested I'm wrong. Just that they just don't know "why". But this has led me to not trust the SOC reading. Further, I have never gotten a SOH reading of less than 100% despite repeated charge/discharge cycles on my 5 year old FLA bank. I find this hard to believe."

The SG200 is working for lots of people. But there is something about my set-up that it causing problems that neither I, nor Balmar has been able to identify. And based on posts elsewhere on the net, I am not alone.

I am planning on replacing my 5 year old FLA bank with a new AGM bank in the next couple of weeks. The FLA bank is old and (I think) tired. And it's a hassle to top of the water. So I'm switching to AGM. Then I'm anticipating having about 3 weeks of live-aboard mooring life with repeated discharge/charge cycles. So it will be interesting to see how the SG200 does.

 

[DDW]

A proper coulomb counting battery monitor does indeed take into account Peukert. I've always considered the Balmar SG200 as a solution in search of a problem. SOH of a battery tells you nothing of value operationally, and can easily be determined with even casual observation of amps and volts.

 

[catalinajack]

So, what is a proper coulomb counting counter? Specific brand, please.

A proper coulomb counting battery monitor does indeed take into account Peukert. I've always considered the Balmar SG200 as a solution in search of a problem. SOH of a battery tells you nothing of value operationally, and can easily be determined with even casual observation of amps and volts.

 

[catalinajack]

And please share with us the method you use to easily determine State of Health.

A proper coulomb counting battery monitor does indeed take into account Peukert. I've always considered the Balmar SG200 as a solution in search of a problem. SOH of a battery tells you nothing of value operationally, and can easily be determined with even casual observation of amps and volts.

 

[catalinajack]

As far as the SG200 being a solution in search of a problem, so what, even if that is true. If the damn thing works as advertised why not use it?

A proper coulomb counting battery monitor does indeed take into account Peukert. I've always considered the Balmar SG200 as a solution in search of a problem. SOH of a battery tells you nothing of value operationally, and can easily be determined with even casual observation of amps and volts.

 

[Flatswing]

I don't get too fussed about the SOH value (mine never got below 95% even when the batteries needed replacing) because SOC , V & A seemed to be fine. Now, I've had two episodes while charging from my 120 A alternator via Sterling Alternator-Battery charger, where the SOC & SOH suddenly drop to 0%, when in fact the charger has hit Absorption & the A are slowly dropping as expected. Had to reset the device each time. then within an hour, SOC returned to normal. I do not have solar, and no other charging device was operative when the SOC value "crashed". Puzzling.

I don't have the Bluetooth module so can't upgrade to 4/2021 software.

 

[sbman]

So, what is a proper coulomb counting counter? Specific brand, please.

The Victron BMV series accounts for Puekert factor, it can be configured based on the manufacturer's specs (if available) or you can use an average value for the chemistry of the battery in use. It does not account for overall capacity loss as the battery bank ages.

The Balmar attempts to use the SOH reading to adjust the SOC reading to the banks present total capacity. If the SOH is low, then the overall capacity of the bank would be diminished so the SOC reading is adjusted to read based on the reduced capacity, at least that is my understanding of the purpose of the SOH value.

A similar function can be performed on the Victron by reducing your bank capacity some amount every few months as the bank ages, you just have to kind of guess how much capacity it's lost over time.

 

[Rossland]

A similar function can be performed on the Victron by reducing your bank capacity some amount every few months as the bank ages, you just have to kind of guess how much capacity it's lost over time.

Guessing is not necessary. See post #14

 

[sbman]

Guessing is not necessary. See post #14

I disagree that performing an SOH test is easy (as post #14 says it is). It can be done of course, but to do it properly and accurately is not easy or convenient and few have the required equipment, technical knowledge or patience to do it properly.

A rough test as you describe in post 14 can provide an estimation which is certainly superior to a guess. How well the SG200 stacks up at making this adjustment in SOH I'm still curious about.

 

[DDW]

The Balmar attempts to use the SOH reading to adjust the SOC reading to the banks present total capacity. If the SOH is low, then the overall capacity of the bank would be diminished so the SOC reading is adjusted to read based on the reduced capacity, at least that is my understanding of the purpose of the SOH value.

But operationally, what do you do with that information? And isn't it counterproductive? I do not use energy as a percentage of capacity, I use energy on an absolute basis: for example the fridge uses say 100 AH in a day. It does not care about or change regardless of SOC or SOH. What I primarily need to know, is how many AH have I used from my battery which must be replaced? The combination of SOC and capacity will tell me that, the battery monitor has done the simple division, but I must then undo the division to see what I've used. The Balmar further obscures the situation by changing the capacity on its own. Now when it gives me a SOC figure I have no idea what I've got. 50% of some number it came up with in the night? That is why I say operationally, it is a step backwards.

The only possible use of SOH is to tell you when you need to replace your batteries, you need to be fairly ignorant about batteries to need to be told but that seems to be their target market.

 

[catalinajack]

But operationally, what do you do with that information? And isn't it counterproductive? I do not use energy as a percentage of capacity, I use energy on an absolute basis: for example the fridge uses say 100 AH in a day. It does not care about or change regardless of SOC or SOH. What I primarily need to know, is how many AH have I used from my battery which must be replaced? The combination of SOC and capacity will tell me that, the battery monitor has done the simple division, but I must then undo the division to see what I've used. The Balmar further obscures the situation by changing the capacity on its own. Now when it gives me a SOC figure I have no idea what I've got. 50% of some number it came up with in the night? That is why I say operationally, it is a step backwards.



The only possible use of SOH is to tell you when you need to replace your batteries, you need to be fairly ignorant about batteries to need to be told but that seems to be their target market.

Update on my experience. As others have, I was having a terrible time getting the read-outs to work. User error. I had my alternators grounded directly to the batteries. Absolutely all grounds must go to a busbar AFTER the shunt(s). I rewired it and after just three discharges and leaving it alone for a week, both banks now show the SOH and have the + sign next the the SOC at 100%. It's just a guess but, for those who have not been able to their SG200 to work, there must be something in your system design that is interfering. Indeed, it was user error on my part.

Say what you will about the utility of this device compared to "standard" battery monitors but what I really like about it is that I can monitor the output of each alternator in real time through the app. I can see the voltage ramp up from 13.1 to 13.5 when they are in bulk and know when they transition to absorb when the voltage jumps up to 14.2 and then higher. My alternators put out 55 - 60 amps each whether in bulk or absorb. The alternators are Balmar 100s. I assume that the regulators are throttling down the output based on the case temp sensor.

Who knows whether the SOH feature will prove to be of any value? I really don't care but I think this product is of great value just for its utility to monitor the alternators. Pair it with Balmar's new regulator and the user can program the regulator through the app. I'm tempted.

I also have two other battery monitors. One is a Series 700 Victron. The other is the control module for my Magnum Energy 2812 inverter-charger. They all work.

By the way, the Magnum 2812 puts out 125 charging amps, about the same as my two alternators combined.

 

[sbman]

Say what you will about the utility of this device compared to "standard" battery monitors but what I really like about it is that I can monitor the output of each alternator in real time through the app. I can see the voltage ramp up from 13.1 to 13.5 when they are in bulk and know when they transition to absorb when the voltage jumps up to 14.2 and then higher. My alternators put out 55 - 60 amps each whether in bulk or absorb. The alternators are Balmar 100s. I assume that the regulators are throttling down the output based on the case temp sensor.
...
By the way, the Magnum 2812 puts out 125 charging amps, about the same as my two alternators combined.

Keep in mind that you are seeing net energy going into / out of the battery. If you have systems in use, that power is not shown on the monitor discreetly, only the net flow in or out of the battery is shown.

Say you have 30 amps of loads and you are charging and the monitor shows 20 amps into the battery. You would have 50 amps of total production from your charging source, whether that is alternators or the magnum charger.

Unless you have a separate shunt on the output of your charging source, or your charging source has a built in meter, or you have zero loads on the system you don't know exactly how much the charging source is producing.

 

[Comodave]

Update on my experience. As others have, I was having a terrible time getting the read-outs to work. User error. I had my alternators grounded directly to the batteries. Absolutely all grounds must go to a busbar AFTER the shunt(s). I rewired it and after just three discharges and leaving it alone for a week, both banks now show the SOH and have the + sign next the the SOC at 100%. It's just a guess but, for those who have not been able to their SG200 to work, there must be something in your system design that is interfering. Indeed, it was user error on my part.

Say what you will about the utility of this device compared to "standard" battery monitors but what I really like about it is that I can monitor the output of each alternator in real time through the app. I can see the voltage ramp up from 13.1 to 13.5 when they are in bulk and know when they transition to absorb when the voltage jumps up to 14.2 and then higher. My alternators put out 55 - 60 amps each whether in bulk or absorb. The alternators are Balmar 100s. I assume that the regulators are throttling down the output based on the case temp sensor.

Who knows whether the SOH feature will prove to be of any value? I really don't care but I think this product is of great value just for its utility to monitor the alternators. Pair it with Balmar's new regulator and the user can program the regulator through the app. I'm tempted.

I also have two other battery monitors. One is a Series 700 Victron. The other is the control module for my Magnum Energy 2812 inverter-charger. They all work.

By the way, the Magnum 2812 puts out 125 charging amps, about the same as my two alternators combined.

What regulator do you have? We had a Balmar in our previous boat and I set the belt load manager down so the alternator wouldn’t put out full rated amps. Maybe your regulator is set so that the output is lower to take it easy on the belts???

 

[catalinajack]

What regulator do you have? We had a Balmar in our previous boat and I set the belt load manager down so the alternator wouldn’t put out full rated amps. Maybe your regulator is set so that the output is lower to take it easy on the belts???

Regulator is a Balmar MC-614. Belt load manager is set at zero. The alternator temp sensor will lower the output and is apparently doing so. Next time out I will shoot the alternator with an IR temp gun and see what's what.

 

[sbman]

Regulator is a Balmar MC-614. Belt load manager is set at zero. The alternator temp sensor will lower the output and is apparently doing so. Next time out I will shoot the alternator with an IR temp gun and see what's what.

You should see maximum charge in the first few minutes of running, while your bank is depleted and the alternators are cool, and it would then taper down. If you aren't seeing higher rates initially, it's unlikely it's a temp related issue. Are you running a centerfielder as well?

 

[catalinajack]

You should see maximum charge in the first few minutes of running, while your bank is depleted and the alternators are cool, and it would then taper down. If you aren't seeing higher rates initially, it's unlikely it's a temp related issue. Are you running a centerfielder as well?

Yes on the Centerfielder.

 

[catalinajack]

You should see maximum charge in the first few minutes of running, while your bank is depleted and the alternators are cool, and it would then taper down. If you aren't seeing higher rates initially, it's unlikely it's a temp related issue. Are you running a centerfielder as well?

I have not checked the amperage at startup. Perhaps it is up there. Will do soon and report back.

 

[DDW]

If you have the alternator temp sensors installed it will definitely ramp back on the charge. Doesn't take long to heat them up, 5 minutes or so. The default temp limit is conservative for HD alternators, and bumping it up just a few degrees can make a substantial difference in the hot output. I run a Delco 28Si, supposed to be rated at 120 deg continuous. The 614 default (100 deg C as I recall) would limit it to about 90 amps once hot vs a 160A spec. I bumped the temp to 107 (again as I recall) and the output now stays close to 110A.

 

[FlyWright]

What regulator do you have? We had a Balmar in our previous boat and I set the belt load manager down so the alternator wouldn’t put out full rated amps. Maybe your regulator is set so that the output is lower to take it easy on the belts???

This is how I run with an MC-614. Allows me to run a 120A alternator derated to 100A on a 1/2" belt. No belt issues...even dust!

 

[catalinajack]

Dockside, I used battery power overnight. I started the engines and and ran them at 1,200 RPM and observed the charging on the Balmar app. It started at 60 amps each bank at 12.9 volts. Then I switched to the inverter charger which is rated at 125 amps. The charging rates to each bank were virtually the same. Would the charge acceptance rate of my batteries be part of the equation? I profess ignorance.