Balmar SG-200 Battery Monitor

[JensLB]

Originally Posted by Wood

Last chance for the SG200.

They have just released firmware updates to the SG200. I upgraded yesterday and did a total reset to see if it’s getting better. This morning 100%+ arrived long before actual thresholds appeared...

This time I just changed bank size and chemistry and left everything else as preset.

//Jens

[lateral]

Originally Posted by steve77

This thread is about the SG200 and the issues various people have had with configuring it to work on their boats. I'm not impressed with your post, which I find completely off topic and not helpful.

Steve

Fair enough, poor taste in view of the fatalities.
I apologise, if that is possible and have asked for it
to be deleted.

As for the device, 1.5 years later l am still
Waiting for meaningful output.
The updates have made it less accurate.

[newhaul]

Here is my take on the sg200. After all of the issues that keep being posted in this thread I'm glad I chose the cheap battery monitor I did . It shows soc ah in and out and instant amps in and out . And all I had to do to set it was discharge my bank to minimum and hook up the monitor to the shunt and charge it to full voltage. One time and it has been accurate for the last 7 months since bringing the new bank online.
What am I missing wrt the sg 200?

[nebster]

I continue to be amazed at how many folks on this thread are struggling to make this thing work, when a simple coulomb counter properly wired will do a perfectly good job.

[steve77]

Originally Posted by lateral

Fair enough, poor taste in view of the fatalities.
I apologise, if that is possible and have asked for it
to be deleted.

As for the device, 1.5 years later l am still
Waiting for meaningful output.
The updates have made it less accurate.

No problem, and thanks for a very classy response.

I also am still working to get the device fully functional The updates haven't helped me, either. Right now the device measures voltage accurately, but not current. Without current, I get zeroes for SOC and SOH. Awaiting another update to address my issues.

Cheers!

Steve

[Wood]

Originally Posted by steve77

No problem, and thanks for a very classy response.

I also am still working to get the device fully functional The updates haven't helped me, either. Right now the device measures voltage accurately, but not current. Without current, I get zeroes for SOC and SOH. Awaiting another update to address my issues.

Cheers!

Steve

How can it not measure current accurately unless there is a hardware failure?

Just curious what you are comparing its measurements against.

[steve77]

Originally Posted by Wood

How can it not measure current accurately unless there is a hardware failure?

Just curious what you are comparing its measurements against.

I have a Blue Seas Systems VSM that has been installed for six or seven years that also measures battery current, voltage, SOC, Amp-hours remaining, etc. It's a very handy unit since it also measures AC voltage, current, and frequency, as well as level of fluid in our holding tank. However, it does not attempt to calculate SOH, which is why I installed the SG200.

When I stated that the SG200 is presently measuring voltage accurately, I compared it to the VSM, the remote display of the Blue Sky solar charger, and confirmed all with my Fluke by measuring at the battery terminals.

The unit did measure current accurately until the last software update. It is possible that the shunt failed coincidentally with the software upgrade, but it doesn't appear likely to me. It isn't that the current display went to dashes (--.-) a day or so later, it happened immediately as soon as the update was complete.

At present, the SG200 reads voltage accurately, but nothing else.

Cheers!

Steve

[Wood]

^^^^
My guess it that condition is a precursor to Balmar implementing AH logging. But is would be nice if they told us. I'll update the firmware this weekend and give the SG200 a few more cycles. Then, if no improvement, take it out. I'm using the REC ABMS which gives accurate data on the lithium battery condition including SOH.

[Prospective]

I downloaded the latest firmware update yesterday. Now to cycle and have it re-learn all over again. I hope it resolves my issues. I continue to have zero confidence in the SOC and SOH readings vs. my battery voltage read via the SG200 and confirmed via another voltmeter. I had the original smartgauge and that was great, so far, this does not seem ready for prime time despite being out for well over a year.

[a64pilot]

Originally Posted by nebster

I continue to be amazed at how many folks on this thread are struggling to make this thing work, when a simple coulomb counter properly wired will do a perfectly good job.

No it won’t. You can actually get closer just watching voltage under load, if you have a chart of voltage that reflects SOC under load.
But an amp counting meter will be accurate when it’s first reset if it’s reset at 100% SOC, and from that moment on it will continue to accumulate errors drifting in accuracy, and requires constant resetting to attempt to maintain accuracy.

An amp counter can maintain decent accuracy as long as bank capacity is tested often and the meter is reset with actual capacity as it changes and the bank is fully 100% recharged more often than not

[nebster]

Originally Posted by a64pilot

No it won’t. You can actually get closer just watching voltage under load, if you have a chart of voltage that reflects SOC under load.

Sentence one is incorrect. Sentence two is true, but I imagine many people don't want to impose that on their families (or themselves).

But an amp counting meter will be accurate when it’s first reset if it’s reset at 100% SOC, and from that moment on it will continue to accumulate errors drifting in accuracy, and requires constant resetting to attempt to maintain accuracy.

It will accumulate errors, but they can be arbitrarily small. My counter is within 5% of true after a month with no resync. That sounds better than some experiences on this thread, doesn't it?

An amp counter can maintain decent accuracy as long as bank capacity is tested often and the meter is reset with actual capacity as it changes

You make it sound like this has to be done all the time. How often does your bank deteriorate a meaningful amount? Maybe I should have included the words "well-cared for" in my assertion.

and the bank is fully 100% recharged more often than not

Nah, they work fine without synchronization most of the time. One out of every 20 or 30 charges is sufficient, if the shunt is properly calibrated.

[JensLB]

SG200 testing continues...

Now I’ve had a few mornings with similar behaviour.

It still feels a bit optimistic regarding SOC as it shows 89% with a voltage at 12.27V and a few amps discharge when I wake up. I have turned the solar panels so they won’t charge in the morning sun.

I can report that the 100%+ SOC has not developed to being better. Now it seems to suddenly jump from 89-90% at a shown voltage of ~12.8V and a couple of amps charging to 100%+. Factory presets for my banks chemistry and size. This takes around 10-15 minutes from when I turn the solar panels to the sun.

SOH has stabilised at 85% which seems reasonable. A funny thing is that the readings changed a lot in the beginning, but only when disconnecting the app and connected again.

//Jens

[JensLB]

Reading the article on marine how to, about under load voltage vs SoC. Gives me the feeling that this bank is closer to 50% than 82%...
https://marinehowto.com/under-load-b...oltage-vs-soc/

[Prospective]

Originally Posted by JensLB

Reading the article on marine how to, about under load voltage vs SoC. Gives me the feeling that this bank is closer to 50% than 82%...
https://marinehowto.com/under-load-b...oltage-vs-soc/

Exact problem I'm having. Way overly optimistic on SOC relative to the voltage.

[Wood]

Originally Posted by steve77

<snip>
The unit did measure current accurately until the last software update. It is possible that the shunt failed coincidentally with the software upgrade, but it doesn't appear likely to me. It isn't that the current display went to dashes (--.-) a day or so later, it happened immediately as soon as the update was complete.

At present, the SG200 reads voltage accurately, but nothing else.<snip>

I just updated firmware and current reading was not affected. SOC is off my ~20% low. SOH is not calculated yet But if the SOC differential remains the same it will come up with an erroneous SOH number again.