Victron Shunt settings. Help please.

[mvweebles]

Right now, I'm pulling drywall at our house and the only power we have is a simple 100w panel driving a 100ah LFP battery via a Victron 75/15 MPPT. I also installed a Victron Smartshunt. All this to run a small fridge and recharge my cordless tools which has been invaluable.

I cannot get the monitor to read properly.

First. It's bright sun here today. Gorgeous day to pull Sheetrock

#1. At 11:30 this morning, shunt showed showed system voltage of 12.83v and consumed AH of 60.6ah.

#2. One hour later (12:41) voltage has increased to 12.97v so clearly it's receiving a charge from the MPPT, but the AH consumed continues to increase negative (as does the SoC).

#3 for reference, here are my battery settings on the shunt.

#4. And the settings on the MPPT

So the system is charging fine but the readings are not correct - AH consumed are not adjusted for solar charge from MPPT. What am I doing wrong?

Thanks in advance

Peter

 

[more]

first set mppt charger on lifepo4 not used defined.
second on 12,83v battery is on 5-10%

set charging 14,4

 

[rslifkin]

Is the ground for the MPPT going through the shunt? If anything is grounded directly to the battery and not through the shunt then it won't be measured.

 

[Delta Riverat]

And you need to cancel the equalization.

 

[luna]

First, I don't own any Victron gear.

From your displayed values, I would at least do these things to improve accuracy.

Set Peukert Exponent to 1.0 or whatever your battery manuf. says it is. 1.25 is a typical lead acid value.

Set Charge Efficiency to 98% or whatever the battery manuf. says.

If possible, set Auto Equalize to never, or get an understanding of what it is and set it correctly.

Then I think you need to get the battery to fully charged and manually set the current state of charge to 100%.

Read to find out what the actions mean for Sych SOC to 100% and Battery SOC on Reset and chose if you want to implement these actions.

Set all other parameters to whatever the battery manuf. recommends.

RTM.

Hope this helps.

 

[Barking Sands]

First...double check Shunt wiring. Is it backwards? Coming off the batt negative terminal? And all grounds only coming off the shunt?

[battery neg]----[batt side-SHUNT- load side]---all negatives

no other terminals on the batt negative except the shunt as above.


Charge settings:

* Disable equalization
* Set absorption a bit higher to 14.2 IMO to take advantage of limited solar. This will result in faster charge times for the last 5-10% as compared to your current settings
* Float 13.5 (slightly above resting voltage) so if it hits the 14.2 and gets full absorb time it will automatically drop to 13.5 and not be held at higher voltage excessively. 13.5 after absorption is still 100%

Shunt setting to change:

* Charged voltage is .2 volts below absorption or 14.0v
* Puekert 1.04
* Charge efficiency 98 or 99%

 

[DDW]

I'm not seeing those two snapshots in time as inconsistent. In the first one, you are drawing near 5A from the battery, a significant load (from a static voltage point of view) on a 100AH battery. In the second, only 0.5A, so static voltage could easily be more because the load is less. You've consumed 4AH in between, probably due to the ~5A draw.

The one of the panel shows 5 amps output, without knowing the load on the battery, hard to know what's going in or out.

 

[tiltrider1]

First...double check Shunt wiring. Is it backwards? Coming off the batt negative terminal? And all grounds only coming off the shunt?

[battery neg]----[batt side-SHUNT- load side]---all negatives

no other terminals on the batt negative except the shunt as above.


Charge settings:

* Disable equalization
* Set absorption a bit higher to 14.2 IMO to take advantage of limited solar. This will result in faster charge times for the last 5-10% as compared to your current settings
* Float 13.5 (slightly above resting voltage) so if it hits the 14.2 and gets full absorb time it will automatically drop to 13.5 and not be held at higher voltage excessively. 13.5 after absorption is still 100%

Shunt setting to change:

* Charged voltage is .2 volts below absorption or 14.0v
* Puekert 1.04
* Charge efficiency 98 or 99%

This is the first thing I would check. It is so easy to accidentally get the shunt turned backwards. Add to that most don’t realize the shunt has a specific direction.