RV.Net Open Roads Forum: Confusing readings on Victron SmartBMB and Smart Solar

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Confusing readings on Victron SmartBMB and Smart Solar

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Sponsored By:
EMD360

Arvada, CO

Senior Member

Joined: 01/18/2010

View Profile



Good Sam RV Club Member


Posted: 09/07/21 05:05pm Link  |  Quote  |  Print  |  Notify Moderator

I can accept that the portable solar array is underperforming. I’ve been trying to use it with my lithium battery set up for a couple of quite sunny days with very low watts readings. But I don’t understand why the BMV is reading less than 50% charge and the solar is reading float. Perhaps because there is not enough charge for bulk or absorption? The portable array is about a year old and I used it on my old RV but not that much and on SLA and with a cheap 15amp controller. I have 210 ah of battery and set at 14 ah for full charge. Had it set higher but it seemed that it had been so long since a full charge(9 days) plugged into shore power I thought the charger was not bringing it to full. It’s been hot. I’ve had the automatic vent fan going full time but it seems the Progressive Dynamics charger would overcome that small load.
The settings are otherwise as recommended. 90% depletion, 0% tail and 99% efficiency. I entered 200 ah capacity.
[image]
And solar reading
[image]
Hope there is a good explanation for these numbers.


2018 Minnie Winnie 25b New to us 3/2021
Former Rental Owners Club #137
2003 Itasca Spirit 22e 2009-2021


2oldman

NM

Senior Member

Joined: 04/15/2001

View Profile


Online
Posted: 09/07/21 05:56pm Link  |  Quote  |  Print  |  Notify Moderator

I have to reset the 'full charge' indicator a couple times to get it right.

3 tons

NV.

Senior Member

Joined: 03/13/2009

View Profile


Offline
Posted: 09/07/21 06:09pm Link  |  Quote  |  Print  |  Notify Moderator

Perhaps I’m not fully understanding the issue, but based on the data provided it appears that the solar controller input voltage is quite satisfactory, thus controller could be in float per it’s algorithm…Assuming that this might be true, then my guess is that the SOC is merely in need of synchronization…To confirm, isolate battery, wait a few before checking voltage…

3 tons

EMD360

Arvada, CO

Senior Member

Joined: 01/18/2010

View Profile



Good Sam RV Club Member


Posted: 09/07/21 09:03pm Link  |  Quote  |  Print  |  Notify Moderator

Thanks, I plugged in the RV for the night and I’ll check for full charge in the morning and do a synchronization.

EMD360

Arvada, CO

Senior Member

Joined: 01/18/2010

View Profile



Good Sam RV Club Member


Posted: 09/08/21 01:23pm Link  |  Quote  |  Print  |  Notify Moderator

Interesting. I can’t really figure this out. Charged all night then turned off the battery power switch and tested voltage,13.49v. BMV reads 99% so I think I have some mistake in the settings. So I unplug and start engine to use DC to DC charger hoping I can get 100% and re-synchronize. I check voltage and it is of course reading 14.34. 14.4 is set as 100%. I turn off the engine and disconnect batteries and get a 14.35 reading on the multimeter. So I re-set the BMV to 100%. The outcome I expect is that further charging from the PD will still be necessary. So now with the engine off but the charger running the isolated batteries read 14.5 instead of 13.49. Charging now at the higher rate but while disconnected?
[image]
But when I disconnect the batteries and unplug the RV I’m getting 14.04. I don’t understand how that little time on the DC charger could up the voltage by that much. And when I turn the battery switch back on without charging the voltage drips precipitously. I’m thinking it might stabilize at the original 13.49v but although it slows down it still shows about 3 min of time left for each minute that passes!
[image]
And I guess the SOC does not reflect this change. Maybe because it needs 10 min averaging. But I still think I’ve made a logic error in the settings.
I switched from 200ah to 210ah. Full charge voltage is reset to 14.5. So if the battery is depleted at 11.5 volts I have 3 volts of battery power. 13.5 is about a third depleted. So I reset the SOC manually to 65%.
After about 30 min of battery use I’m showing 13.27v. 64% SOC and an astounding 1 day left of battery power! Under the same load that gave me only 7 hours last I checked.
So what happens if I plug the PD charger back in?
It starts sending a good amount of charge into the batteries. Hopefully up to 14.4 or 5.
[image]
This is still under the fan load. And I would expect exactly this behavior. Charge going in SOC increasing. But I’m not seeing the opposite except when I left the application for 30 min. SOC stays at 100% even thought I’m using battery power at what is being calculated at a quick pace.
Original problem was BMV read 100% at ~13.5 volts. Reset SOC to higher voltage using DC to DC charger following advice here. Charged only briefly voltage multimeter reading increased about half a volt. Running load for about 15 min decreased voltage quickly. Verified with multimeter. No decrease in SOC.
Reset parameters in application. I had 90% depletion floor but I changed that to 20%. Thinking it meant percentage left not percentage used. Retested and it appears SOC is responding to actual depletion. Just checked again and SOC is 100%.
[image]
But not showing the fan load! Reset the battery switch and now it’s showing the ongoing load and a drop to 14.1v. And again dropping fast. This is so weird.
[image]
So something is wrong here or this BMV takes a long time to get set correctly. What am I missing? Is it time to call Victron?

Bobbo

Wherever I park

Senior Member

Joined: 09/16/2007

View Profile



Good Sam RV Club Member

Offline
Posted: 09/08/21 09:22pm Link  |  Quote  |  Print  |  Notify Moderator

A battery will hold a surface charge for a while making its voltage look artificially high. Let it rest a couple of hours before taking the reading, or put a significant load on it for a minute to draw off the surface charge, then take the reading.


Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB


EMD360

Arvada, CO

Senior Member

Joined: 01/18/2010

View Profile



Good Sam RV Club Member


Posted: 09/08/21 09:27pm Link  |  Quote  |  Print  |  Notify Moderator

More research. Found the exact settings for the Lion batteries.
https://community.victronenergy.com/stor........nfig-for-victron-bmv-battery-monitor.pdf
Also a post from someone with the same odd performance although the secret there was upping his charged voltage.https://www.wanderthewest.com/forum/topi........th-not-adding-up-on-solarbattery-system/
Mine was already high. I lowered it to 13.9.
Advice was to charge completely and reset at night with no solar input. But that doesn’t really apply. I reset this morning after charging g to at least 14.04. He seems to have fixed the BMV readings though.
This AMsolar video https://m.youtube.com/watch?v=tV055vmZgvYexplains when the meter reads 100% charge and battery voltage is down then there could be an issue with wiring. I know all my negatives are on the shunt but I will check them all tomorrow.

EMD360

Arvada, CO

Senior Member

Joined: 01/18/2010

View Profile



Good Sam RV Club Member


Posted: 09/13/21 12:54pm Link  |  Quote  |  Print  |  Notify Moderator

Might as well follow up as there may be someone who experiences odd behavior on the Victron BMV 712. It appears to be working although I still get 100% when I’m connected to shore power but the battery is only showing 13.27 volts. I’m assuming like the light meter on the rv panel it assumes the battery is running at full power so the dial reads 100% when plugged in.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 

Open Roads Forum  >  Tech Issues

 > Confusing readings on Victron SmartBMB and Smart Solar
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.