A Forum run by Enthusiasts of MidNite Solar

MidNite Solar Monitoring software and hardware => Local App software => Topic started by: openplanet on June 15, 2020, 12:30:47 AM

Title: Voltage reading discrepancy
Post by: openplanet on June 15, 2020, 12:30:47 AM
Attached are two screen shots, each of the same place in LocalApp for my two Classics, named "Upper" and "Lower."  Note that for Upper, the battery voltage indicated on the dashboard is the same as that in Config/Tech/Offsets (and also the same as what my BMS reads.)  Now look at the screen shot for Lower. 
Can anyone explain why the dashboard reading doesn't reflect the corrected voltage as seen in Config/Tech/Offsets?

Thank you.
Title: Re: Voltage reading discrepancy
Post by: boB on June 15, 2020, 03:22:32 AM

I'm not exactly sure.    But have you tried changing the offsets of the lower  to 0  instead of 0.3 ?

Does it then agree with the upper ?

These types of things are maybe why Greg at Trace only set voltage readings for 48V systems at a 0.4 volt resolution on
their SW inverter ?

Did you change the offset to 3 or was it like that when you got it ?

Or maybe I read you wrong and you need to change the upper to 3 and put the lower back to 0 ?

Do you have  Fluke meter ?   That's a good standard.
Title: Re: Voltage reading discrepancy
Post by: ClassicCrazy on June 15, 2020, 01:14:55 PM
Not sure if this is the case with this setting but some things in the Local App don't work correctly.
Try setting it via the MNGP and see if there is any difference.

Larry
Title: Re: Voltage reading discrepancy
Post by: openplanet on June 15, 2020, 01:29:46 PM
OK, I'll give that a try when I get home.
Odd thing is that the voltage reading in the dashboard dial is always .2 volts lower than the corrected voltage set in config/tech/offsets. 
Title: Re: Voltage reading discrepancy
Post by: ClassicCrazy on June 15, 2020, 11:57:32 PM
Is this what you are seeing ?

LOCAL APP BUG
PV INPUT and BATTERY DIALS do not readout OFFSET VALUES, they read out exactly what is present at the blue terminals.
(You need to go to CONFIG / TECH and go down to the OFFSET OPTION to read the OFFSET VALUES)  What this means is if you set an OFFSET the dial will not show this offset voltage, it will remain displaying the "raw" Battery voltage.

from Midnite Knowlege base
http://www.midniteftp.com/support/kb/faq.php?cid=4

Larry
Title: Re: Voltage reading discrepancy
Post by: openplanet on June 16, 2020, 10:22:54 PM
Yes! That is exactly what I am seeing Larry.
Thank you!
Title: Re: Voltage reading discrepancy
Post by: boB on June 17, 2020, 04:54:45 AM

Changing that offset is especially weird when the Classic is in Absorb or Float because since the Classic is trying to keep the voltage constant, the Classic's battery voltage meter does not change when you are adjusting it !

Another thing to add to the pile of knowledge.

Thank you Larry !!