Anyone have trouble with smartshunt?

[outboard1196]

Has anyone had issues with victron smart shunts before ? I had a weird issue today and I don't think it's the smart shunt but something seem odd. I was running a 3d printer off battery for 4 hrs started the print and checked the smart shunt was cycling 6-12A at 12V. Checked on it every half hr and towards the end I noticed it was now drawing 25 A when the heaters turned on . after looking at the specs for the printer 25A is correct ( around 300W). after shutting everything down and starting the printer up again it was drawing 25A again. The build plate was hot at the beginning I remember feeling it . So the heaters where running ( maybe at reduced power ?)
I've had no issues with other victron hardware before. I confirmed I was getting 12A at 24v at the power supply for printer as well.
Thinking back I think it was pulling 24A at 12v last time I ran the printer but I don't have history that far back.

 

[rodrick]

Doubtful it was the shunt giving bad info I’d bet on the printer not functioning correctly

 

[sunshine_eggo]

I'm not really sure what you see as a problem.

I don't have a smartshunt. I have a BMV-702, which is basically a smartshunt without bluetooth, but it has an external display.

I have never had a case where it didn't 100% agree with my Batrium shunt or a manual measurement.

Note that logging resolution changes with age:

• 2m at 1s interval (RAM only)
• 2h at 30s interval
• 1d at 5m interval
• 45d at 30m interval

It's very possible that when you're looking at older data, you're not seeing the same activity that you see when actively looking at it.

 

[outboard1196]

I'm not really sure what you see as a problem.

I don't have a smartshunt. I have a BMV-702, which is basically a smartshunt without bluetooth, but it has an external display.

I have never had a case where it didn't 100% agree with my Batrium shunt or a manual measurement.

Note that logging resolution changes with age:

• 2m at 1s interval (RAM only)
• 2h at 30s interval
• 1d at 5m interval
• 45d at 30m interval

It's very possible that when you're looking at older data, you're not seeing the same activity that you see when actively looking at it.

It was up to date data , for 3 hrs the graph looks like the data on the left then it changed to what's on the right . I restarted the app many times. Nothing else was connected to the battery . I'll look again tomorrow.

 

[sunshine_eggo]

It was up to date data , for 3 hrs the graph looks like the data on the left then it changed to what's on the right . I restarted the app many times. Nothing else was connected to the battery . I'll look again tomorrow.

I see that you replied to my post and even quoted it, but maybe you missed it? Or maybe you didn't understand it?

• 2m at 1s interval (RAM only)

The choppy stuff is the last 2 minutes of data at 1 second intervals.

• 2h at 30s interval

After 2 minutes and up to 2 hours, it's at a 30 second interval

Maybe this explains it graphically?





Based on the information you've presented, and the data published concerning VictronConnect logging behavior in all victron bluetooth shunts and MPPTS, your smartshunt is behaving exactly as it should.

Data density changes with time. Older data has less data points than new data and more closely represents the average for a given time period rather than absolute mins or maxes.

Your printer behavior is as you observe in the last two minutes. Older than two minutes, the values are based on the average over a 30 second period.

 

[outboard1196]

I see that you replied to my post and even quoted it, but maybe you missed it? Or maybe you didn't understand it?



The choppy stuff is the last 2 minutes of data at 1 second intervals.



After 2 minutes and up to 2 hours, it's at a 30 second interval

Maybe this explains it graphically?


View attachment 247163


Based on the information you've presented, and the data published concerning VictronConnect logging behavior in all victron bluetooth shunts and MPPTS, your smartshunt is behaving exactly as it should.

Data density changes with time. Older data has less data points than new data and more closely represents the average for a given time period rather than absolute mins or maxes.

Your printer behavior is as you observe in the last two minutes. Older than two minutes, the values are based on the average over a 30 second period.

I understand what your saying .
I didn't know it averaged data points as it aged , but makes sense . I forgot to check the graph this morning , I'll check ttonight.

 

[sunshine_eggo]

You might get different results with live monitoring, i.e., if you pull it up and don't let your phone sleep, I believe it will retain the finer granularity in the app itself, but once that session is closed, it only stores the data according to the above schedule.

 

[outboard1196]

You might get different results with live monitoring, i.e., if you pull it up and don't let your phone sleep, I believe it will retain the finer granularity in the app itself, but once that session is closed, it only stores the data according to the above schedule.

I looked last night and the graph when using the printer was a constant -11A now . So it was just an averaging issue I witnessed, never noticed till you pointed it out . Never doubt a victron