Want Opinions on Battery Monitors with SOH

[Shiny]

After digesting and exchanging info on this forum, I've decided to add a battery monitor and think a State of Health estimate would be valuable for us.

There are many threads and discussions about battery monitors but few address the SOH feature so I decided to open a "focused" thread.

My impression is the SOH feature addresses the need to "guess" about "true" capacity (needs user input) if relying on SOC. Estimating this "true" capacity and degradation over life is the primary reason I want a monitor. I also understand the capacity can be estimated by monitoring behavior over time but I like the "let the machine guess" approach promised by SOH.

I find two product options:

Balmar SG200/SG210

Veratron IBS 12V/Display

Like all shunt-based monitors without SOH estimation, these provide the "standard" voltage, current, power, and SOC monitoring. Both have a bluetooth interface and phone apps. Installation/packaging of the Veratron looks pretty slick.

Please:

- Any direct experience with either of these products?

- Any pros and cons regarding the SOH feature and/or reasons other brands without SOH were chosen over these two?

Thanks in advance,

Mike

 

[Shiny]

No responses here but after reading more online I'm leaning toward getting both the (Balmar or Veratron) and a Victron SmartShunt.

I really want the SOH function promised by the Balmar and Veratron systems.

The Victron SmartShunt will allow me to capture the more "direct" AH in and out, along with being able to capture the history. The SmartShunt is very affordable without need for a display. I can add a display later if we miss it.

Both will provide an SOC indication. The hope is the (Balmar or Veratron)'s is more realistic without having to "calibrate" as I perceive is needed for a high-confidence capacity estimate (SOH) from the Victron. But the accurate insight of our daily usage and charging provided by the Victron will be a big improvement over the GoPower metrics and a basis for "informed" future decisions.

I like the apparent quality (and perceived engineering) of the Veratron/VDO hardware, simplicity of the installation, and nice configurable display. Their system does not currently advertise support for lithium chemistries (mine are Pb-acid) nor does it allow for "easy" data logging. The ability to add a network link (NMEA 2000) is cool for integration/expansion but my needs are presently simpler. As a standalone "smart" battery monitor (no network link, no bluetooth) it is a nice system but seems to lack features built into the Balmar products. I am still waiting on pricing for the "standalone" Veratron monitor (B00084701) which seems to be a recent configuration. If it is significantly less than the Balmar, I might go with Veratron as the Victron SmartShunt will enable capturing and logging more data than I can ingest.

 

[MVA]

It depends on the type of battery you wish ot monitor. An inexpensive one that worked very well for me is the AiLi, available at Amazon:
https://www.amazon.com/AiLi-Voltmeter-Ammeter-Voltage-Motorhome/dp/B07CTKYFTG?th=1

After I changed over my DC system to LiFePO4, I upgraded to a Victron SmartShunt. I just (last month) installed the SmartShunt so I have minimal expectance with it but expect it to work well.
YMMV
2 cents

 

[Mike Lewis]

Whatever battery monitor you get, be sure to calibrate it correctly. I replaced my Tri-Metric monitor with a Victron SmartShunt when I installed lithium batteries in my trailer. Apparently I did not calibrate the SmartShunt correctly and I drained my batteries. After calibrating the SmartShunt it works fine now. Learn from my mistake.

 

[Shiny]

It depends on the type of battery you wish to monitor. An inexpensive one that worked very well for me is the AiLi, available at Amazon:
https://www.amazon.com/AiLi-Voltmeter-Ammeter-Voltage-Motorhome/dp/B07CTKYFTG?th=1

After I changed over my DC system to LiFePO4, I upgraded to a Victron SmartShunt. I just (last month) installed the SmartShunt so I have minimal expectance with it but expect it to work well.
YMMV
2 cents

Thanks. I think the Victron SmartShunt will provide a lot of insight into our actual usage and what's really going on with the solar charging.

Whatever battery monitor you get, be sure to calibrate it correctly. I replaced my Tri-Metric monitor with a Victron SmartShunt when I installed lithium batteries in my trailer. Apparently I did not calibrate the SmartShunt correctly and I drained my batteries. After calibrating the SmartShunt it works fine now. Learn from my mistake.

Ouch, sorry that happened and hope it didn't hurt the batteries. I will try to pay attention but am quite capable of mistakes.

..................

As to my original question - I'm really hoping the Balmar and/or Veratron can estimate the "true" capacity of our batteries (State of Health) as they age and hoping someone here has experience. This all stems from my experience last summer where I concluded our batteries were not delivering anything close to their "new"/advertised capacity. Here is a thread where I asked for help interpreting the GoPower metrics:

https://www.escapeforum.org/forums/f38/how-to-interpret-gopower-21541.html

I am too lazy and/or unmotivated to pull the batteries and attempt to measure the "true" capacity or pay someone else to do it. A monitor that can deliver a reasonably accurate SOH will make it MUCH easier.

There is no doubt the Victron and other monitors that use a shunt can accurately measure both current and "integrated" amp-hours. I know this will add a lot of value vs the limited info from the GoPower controller but will not estimate "true" capacity nor monitor degradation over time.

This is the best summary with recent comments I've found for the Balmar/SOH feature:

https://panbo.com/balmar-sg200-a-good-battery-monitor-gets-better/

There is more updated product info on the Balmar site but feedback/reviews since reported correction of what appear to be "early" issues are scarce. This is what I was hoping to flush out from this forum.

I think the Veratron system may not have as much time on the market but also claims to provide a State of Health indicator. I have yet to find any feedback from real users online, hence my post here. Veratron sent me a datasheet for their most basic configuration and it looks VERY easy to install and use.

 

[Centex]

- Any pros and cons regarding the SOH feature and/or reasons other brands without SOH were chosen over these two?

From the Balmar SG200 product page:
State of Health (SoH%)
Proprietary self-calibrating algorithm determines how your battery has aged from its original capacity.

From the Balmar SG200 Manual:
Parameter - State of Health (SoH)
Unit - Percent (%)
Note - SoH is the battery’s existing, or actual aged capacity compared to the initial design capacity.
________________

Personally, I've never understood the value of an estimated % expression of a battery's 'aged-capacity' relative to its 'design capacity'. My iPhone provides that but knowing that particular bit of estimated data (unlike State of Charge, for example), I can't see how that data factors into any suggested action relating to use of the battery or the device(s) it supports.

Perhaps it eventually has value as a 'warning of impending end-of-life' for the battery so one can anticipate another big expenditure?

Please help me understand, why do you "think a State of Health estimate would be valuable for us"; how do you envision utilizing that "SoH %" in any manner?

 

[Shiny]

.....
Perhaps it eventually has value as a 'warning of impending end-of-life' for the battery so one can anticipate another big expenditure?

Please help me understand, why do you "think a State of Health estimate would be valuable for us"; how do you envision utilizing that "SoH %" in any manner?

I don't want to start a debate, just asking if anyone has experience with a Balmar or Veratron monitor. But to answer your question, I don't think SOH is directly useful. I think the value will be having SOC automatically updated as the battery ages.

My goal is simply to know how much capacity I have. The GoPower tells me "100%" but it doesn't tell me if my 220 AH battery has degraded and is now a 100 AH battery. This creates risk for overdrawing the battery and further shortening its life. Knowing the true capacity (ie trusting the SOC below 100%) will be a useful guide for decisions, whether charging, replacement, or needing additional capacity.

 

[Centex]

I don't want to start a debate ....

Nor do I.

My comments / questions were implicitly in response to your question "..reasons other brands without SOH were chosen over these two?"

Making it explicit - I've chosen another brand without SOH (Victron BMV-712 with shunt) because I didn't see value for me in an estimated remaining battery life display (aka SOH as implemented by Balmar). Not debating, just stating the fact in response to the question.

Thank you for the explanation of the value you see in Balmar's SOH for yourself.

 

[Shiny]

I plan to buy a Victron SmartShunt, maybe for the same reasons you bought the BMV-712.

I'm curious how you interpret and use the data from yours.

Do you update the settings to provide a more accurate indication of SOC or do you just know you have a lot of margin for capacity and don't need to know if the battery has degraded?

Or maybe the risk for damaging the battery by over-drawing is unique to Pb-acid and those with lithium batteries can draw down to zero without worrying about it?

This topic surfaced for us because we need to power 2 CPAPs overnight and with the furnace on, we would wake to the GoPower charger telling us we were consuming near or over half the capacity. This didn't make sense if the batteries had 220 AH capacity and got me thinking our Pb-acid batteries (we bought the trailer used) may be significantly degraded. I had no way to measure this without pulling the batteries, buying a load, and measuring. I don't want to go through all that and hope a Balmar or Veratron device will tell me.

 

[Shiny]

Well.... I just learned the SmartShunt does not retain data and reportedly has a very short bluetooth range. I am now leaning toward the Thornwave device to provide the A, AH, V, and SOC data logs. It will cost more but the logging is worth it.

I talked to Thornwave and was told the SOC will recalibrate under some conditions. I think this means if I fully discharge the batteries the recharge will allow the device to estimate true capacity and form the basis for SOC below 100%. I suppose this is also true for a Victron monitor. Doing this occasionally probably won't hurt the batteries much...

hmmm....

 

[Centex]

I'll try to answer the several questions ...

First, my storage is this BestGo LiFePO4 battery, rated at 400Ah / 5.12kW. So yes, compared to a Pb-based chemistry I'm relatively less concerned about age-related capacity loss (it'll happen, but likely over a very long term in comparison).

Second, the kit of the Victron BMV-712 Smart (datasheet here) which includes both the display component and the 500A/50mV shunt, does offer historic data logging and retrieval. That capability may be limited compared to some other competitive brands, and that capability may not be provided by the 'bare SmartShunt' (sans display component) which Victron also offers, I don't know.

For my purposes I think the data provided by the Victron components will facilitate reasonable management of my battery and loads, primarily by monitoring voltage and Ah in/out. Separate from the BMV-712 monitoring, my Victron Smart Solar Controller and my xantrex Freedom XC 2000 Charger/Inverter provide automated low and high voltage cutoffs (to help ensure I don't draw-down the battery to a damaging level and don't overcharge the battery). Between all of that I think I can derive my own 'capacity estimate' based on use experience specific to my battery and use-habits, even as the battery ages over a very long term.

All of this equipment is relatively new to me; my hope and expectation is that, with a bit of time and experience, I won't be focused on this stuff at all, my use-habits will evolve as I learn and get comfortable with what the system's capabilities are and monitoring activities will be fewer and farther between. My ultimate interest is enjoying camping, not being focused on the technology and tools which facilitate that.

Insofar as Bluetooth range, that's not an issue for me, I don't have any problems in that regard with the Victron stuff communicating within my trailer and to the cab of my truck while in tow - that's all I need, YMMV.

I'll readily admit that Victron gear may not have some useful features that others offer, IMO every choice involves some sort of compromise. In no small part I chose to vest in Victron because the basic reputation for functionality, robust-ness, and support seems well established (that may well be true of other brands). I also find it's easier for me to learn and get comfortable with one company's relatively uniform interfaces (in contrast to having components from multiple companies with different 'styles of interface').

Again, not to replying debate, just stating my approach as requested while recognizing that my approach may well not be suitable for you (or anyone else) and your situation or habits.

We each do it in our own way, but as long as we Have Fun IMO that's what counts!

 

[Shiny]

Alan,

I'll try to answer the several questions ...

Very helpful and greatly appreciated.

First, my storage is this BestGo LiFePO4 battery, rated at 400Ah / 5.12kW. So yes, compared to a Pb-based chemistry I'm relatively less concerned about age-related capacity loss (it'll happen, but likely over a very long term in comparison).

Both the lithium chemistry and the large capacity are differences that could drive different priorities. As I understand, you don't have to worry much about "over-drawing" your battery. And having 400 AH greatly reduces the chance it will happen vs our ~100 AH @ 50% SOC target. The guidance to keep our Pb-acid above ~50% SOC is what makes me want to have confidence in this metric.

Second, the kit of the Victron BMV-712 Smart (datasheet here) which includes both the display component and the 500A/50mV shunt, does offer historic data logging and retrieval. That capability may be limited compared to some other competitive brands, and that capability may not be provided by the 'bare SmartShunt' (sans display component) which Victron also offers, I don't know.

This is great. I will look more closely at this configuration. I was disappointed to learn the standalone BT-enabled SmartShunt did not allow long-term logging.

For my purposes I think the data provided by the Victron components will facilitate reasonable management of my battery and loads, primarily by monitoring voltage and Ah in/out. Separate from the BMV-712 monitoring, my Victron Smart Solar Controller and my xantrex Freedom XC 2000 Charger/Inverter provide automated low and high voltage cutoffs (to help ensure I don't draw-down the battery to a damaging level and don't overcharge the battery). Between all of that I think I can derive my own 'capacity estimate' based on use experience specific to my battery and use-habits, even as the battery ages over a very long term.

Understood and am envious of the capabilities. I just don't know if a BMV-712 will automatically adjust SOC for degraded capacity, nor do I know if I can gain confidence just by monitoring usage and charging. Maybe so!

All of this equipment is relatively new to me; my hope and expectation is that, with a bit of time and experience, I won't be focused on this stuff at all, my use-habits will evolve as I learn and get comfortable with what the system's capabilities are and monitoring activities will be fewer and farther between. My ultimate interest is enjoying camping, not being focused on the technology and tools which facilitate that.

I share the goal of not being focused on it. I just haven't gotten there yet but did conclude I need more than the GoPower solar controller measures. It works well as a charger so far, just lacks the more direct insight provided by the Victron and other shunt-based monitors.

Insofar as Bluetooth range, that's not an issue for me, I don't have any problems in that regard with the Victron stuff communicating within my trailer and to the cab of my truck while in tow - that's all I need, YMMV.

Sounds great. Lots of feedback on Amazon suggests the standalone SmartShunt BT transmitter may not perform as well as your system, but the lack of log retention is a bigger deterrent for me.

I'll readily admit that Victron gear may not have some useful features that others offer, IMO every choice involves some sort of compromise. In no small part I chose to vest in Victron because the basic reputation for functionality, robust-ness, and support seems well established (that may well be true of other brands). I also find it's easier for me to learn and get comfortable with one company's relatively uniform interfaces (in contrast to having components from multiple companies with different 'styles of interface').

Again, not to replying debate, just stating my approach as requested while recognizing that my approach may well not be suitable for you (or anyone else) and your situation or habits.

We each do it in our own way, but as long as we Have Fun IMO that's what counts!

Understood and appreciated!

Mike

 

[cpaharley2008]

This thread is way beyond my experience level with Escape's electronics.....I have just the basic setup I guess....The Yugo of electronics........

 

[Centex]

Mike, on the BT range issue alone -

With the BMV-712 setup I purchased I'm pretty sure the BT transceiver is in the display component rather than on the shunt. The two are connected by an included, easy to route, and generous length (~20+ft IIRC) RJ-12 cable, allowing the display to be quite remote from the shunt.

In my case the display is installed in the face of the cabinet above the fridge, while the shunt is buried among other dense electrical gear adjacent to the battery under the rear dinette bench.

That might benefit the 'useful range' factor?

Understanding that's just one of many factors in your equation (and yep, ours are quite different on a number of fronts) but thought worth a mention.

Have Fun!

 

[Tin]

Your go power solar controller is not a battery monitor. ( its junk )
1. You need a good mppt solar controller. ( Victron is very nice)
2. You need a good battery monitor. ( Victron is very nice)
3. You need more battery storage for the amount of AH you are using.
( 220 Ah of flooded lead acid batteries will not cut it )
and yes your batteries are more than likely toast already.

 

[hugh]

In any given charge cycle, your monitor's estimation of remaining capacity could be off by 1-2% or more, assuming it's calibrated correctly. With typical battery capacity degradation, your battery will lose 0.005% - 0.01% capacity per cycle. Effectively, that means it would take several hundred cycles of your battery before the actual loss in capacity made any real difference to the remaining capacity estimate during use. And unless you're planning to run your battery down to the last few percent of capacity when you use them, even then, it wouldn't impact how you actually used your batteries.



In terms of real "health" data, I think a BMS that provides cell level data on resistance, voltage, balancing activity, etc. would be much more useful to spot any potential problems over time.

 

[Shiny]

This thread is way beyond my experience level with Escape's electronics.....I have just the basic setup I guess....The Yugo of electronics........

Ha! Me too. This stuff is complicated and I want simple.

...
With the BMV-712 setup I purchased I'm pretty sure the BT transceiver is in the display component rather than on the shunt. The two are connected by an included, easy to route, and generous length (~20+ft IIRC) RJ-12 cable, allowing the display to be quite remote from the shunt.

In my case the display is installed in the face of the cabinet above the fridge, while the shunt is buried among other dense electrical gear adjacent to the battery under the rear dinette bench.

That might benefit the 'useful range' factor?....

Have Fun!

Yes, that makes sense. Thanks again.

Your go power solar controller is not a battery monitor. ( its junk )
1. You need a good mppt solar controller. ( Victron is very nice)
2. You need a good battery monitor. ( Victron is very nice)
3. You need more battery storage for the amount of AH you are using.
( 220 Ah of flooded lead acid batteries will not cut it )
and yes your batteries are more than likely toast already.

Agree the GoPower is not a monitor. I don't consider it junk but understand an mppt controller is more efficient and Victron's stuff looks high quality.

Yes, I need a monitor and am close to a decision.

I will be able to answer both the "needed" capacity and the degree of "toast" when I get a monitor! I'll also be in better shape to avoid damaging new batteries when I need them.

In any given charge cycle, your monitor's estimation of remaining capacity could be off by 1-2% or more, assuming it's calibrated correctly. With typical battery capacity degradation, your battery will lose 0.005% - 0.01% capacity per cycle. Effectively, that means it would take several hundred cycles of your battery before the actual loss in capacity made any real difference to the remaining capacity estimate during use. And unless you're planning to run your battery down to the last few percent of capacity when you use them, even then, it wouldn't impact how you actually used your batteries.

In terms of real "health" data, I think a BMS that provides cell level data on resistance, voltage, balancing activity, etc. would be much more useful to spot any potential problems over time.

I obviously know little, but my impression from reading stuff is our "wet" Pb-acid batteries can degrade a LOT if repeatedly allowed to discharge below 50% capacity. I have no idea how well the original owner adhered to this but the limited experience I have makes me think the batteries have lost more capacity than they should if well-managed.

As to the "type" of monitor, I still see advantages to both the "coulomb counters" and the "SOH estimators". I will definitely buy a coulomb counter. Still on the fence about adding the SOH variety.

 

[vermilye]

My problem with the SOH monitors is they are using the same data as a plain old battery monitor such as the Victron 712 or the Bogert 2030. The only things it can monitor are voltage, time & current. They use simple algorithms to determine amp hours, and it you have correctly entered your battery information, remaining amp hours /KW hours, when the batteries are full, etc.

Determining state of health as batteries age without a drawdown test requires more "magic" than I'm comfortable with. I'm not sure I need to use a measuring system to tell me that my batteries are not holding a charge as well as they did in the past or how much I trust the software's conclusion. Battery health is a gradual decline & one that I have plenty of time to determine if I need to replace them.

 

[John in Santa Cruz]

with good LiFePO4 batteries rated for 4000-7000 80% discharge cycles, even if we ran them down hard and recharged them daily, it would take 10-20 years before there would be measurable degradation.

 

[Shiny]

My problem with the SOH monitors is they are using the same data as a plain old battery monitor such as the Victron 712 or the Bogert 2030. The only things it can monitor are voltage, time & current. They use simple algorithms to determine amp hours, and it you have correctly entered your battery information, remaining amp hours /KW hours, when the batteries are full, etc.

Determining state of health as batteries age without a drawdown test requires more "magic" than I'm comfortable with. I'm not sure I need to use a measuring system to tell me that my batteries are not holding a charge as well as they did in the past or how much I trust the software's conclusion. Battery health is a gradual decline & one that I have plenty of time to determine if I need to replace them.

Thank you for adding to the discussion.

Yes, I agree the SOH monitors can only measure volts, amps, and time but clearly they use charge history to estimate capacity as they require multiple discharge/charge cycles. The math is not clear to me either, is proprietary, and in the case of the Balmar devices, has had some issues when first released. This is part of the reason I was looking for someone with recent experience.

As to whether I can gain the same confidence by monitoring AH, I don't think so unless I actually measure capacity with, as you say, a drawdown test.

Do you run drawdown tests to "calibrate" your monitor? My guess is the degradation mechanisms and resulting effect on capacity loss for LiFePO4 does not warrant it.

Do you know a way to estimate capacity of a Pb-acid battery using the data provided by a Victron BMV-712 or similar "coulomb counter"? As I understand, to have confidence in an accurate 50% (or other) SOC measurement, these devices require "calibration" of "standard" capacity, Peukert coefficient, and perhaps other factors.

I also suspect that, as you say, had I been the original owner, installed a coulomb counter when new, and monitored the behavior over time that I would be more comfortable.

with good LiFePO4 batteries rated for 4000-7000 80% discharge cycles, even if we ran them down hard and recharged them daily, it would take 10-20 years before there would be measurable degradation.

Wow, that is WAY friendlier than my wet cell Pb-acid batteries. If I end up replacing mine, I already understand the weight and depth of discharge motivation to spend more for lithium. This lack of capacity degradation is another big motivator. I also understand it would require changing more than the batteries so there is definitely a cost barrier for us, but we are new to all of this RV stuff so still figuring it all out.

Does anyone with Pb-acid batteries routinely run drawdown tests? This may be what I need to do rather than spend money on an SOH monitor but after reading this article, I am convinced knowing the true capacity is a big deal for Pb-acid and cannot be directly measured by a coulomb counter:

https://marinehowto.com/programming-a-battery-monitor/

Thanks again to all for the discussion and education.

Maybe I just need to get a coulomb counter and try to run a drawdown test... but maybe a better idea is just to buy new batteries and move on...

Mike