Update!

[Spower]

So I updated my controller to a victron 100/50 smartsolar (bt)
And the battery monitor to a renogy

Battery monitor is way better than last one!
Controller also seems way better but.....

Controller went into float mode when monitor showed batteries were only at 93%. Why? What would cause this? ?

I have 3 190w panels in parallel, 2 100ah battleborn lithium also in parallel.

Any ideas?

 

[JWLV]

What Victron thinks when a battery is fully charged is completely different than what Renogy thinks.
Just ask the members here on what voltage they think a LiFePO4 battery is fully charged. You'll get dozens of different answers with as many explanations of why.

 

[Spower]

What Victron thinks when a battery is fully charged is completely different than what Renogy thinks.
Just ask the members here on what voltage they think a LiFePO4 battery is fully charged. You'll get dozens of different answers with as many explanations of why.

Soooo? Do I need to change some settings or something?

 

[LakeHouse]

Soooo? Do I need to change some settings or something?

Yes. Your battery monitor will measure current in and out and estimate SOC. This works fairly well, but isn’t exact for a variety of reasons.
But, your monitor has a set point for calibrating to 100% SOC. The ‘Full V’ setting is the voltage measurement where the monitor will assume that the battery is full. Set it to the same as (or maybe 0.1V less than) the SCC’s absorb voltage. Then when the battery reaches the absorb voltage during charging, the monitor resets to 100% SOC. On some other battery monitors you can set Voltage for a certain time, but the Renogy one just gives you the voltage option. Still, it should work alright but might slightly overestimate SOC.

 

[Spower]

Yes. Your battery monitor will measure current in and out and estimate SOC. This works fairly well, but isn’t exact for a variety of reasons.
But, your monitor has a set point for calibrating to 100% SOC. The ‘Full V’ setting is the voltage measurement where the monitor will assume that the battery is full. Set it to the same as (or maybe 0.1V less than) the SCC’s absorb voltage. Then when the battery reaches the absorb voltage during charging, the monitor resets to 100% SOC. On some other battery monitors you can set Voltage for a certain time, but the Renogy one just gives you the voltage option. Still, it should work alright but might slightly overestimate SOC.

That is how I have it set ?

 

[LakeHouse]

That is how I have it set ?

Might need to either go a little lower or have your SCC absorb for longer. When there’s current flowing, the voltage at the SCC and the battery monitor won’t match. If the monitor doesn’t measure high enough voltage it won’t reset.

 

[Spower]

Might need to either go a little lower or have your SCC absorb for longer. When there’s current flowing, the voltage at the SCC and the battery monitor won’t match. If the monitor doesn’t measure high enough voltage it won’t reset.

So let me ask.....the monitor has a Full V setting, the manual says...when the voltage is higher than the set value the capacity will be automatically set to 100%

I have it set to 14.5v since the absorption value in the controller is set to 14.4, Does this sound right?

 

[LakeHouse]

Nope, you'll never get to 14.5V! Your SCC will charge and increase voltage as the battery SOC increases, but it will only go up to a maximum of 14.4V, and then it will decrease current during absorption to not exceed 14.4V.
You need to set your Full V to 14.4V or less, probably more like 14.3.

 

[Spower]

Nope, you'll never get to 14.5V! Your SCC will charge and increase voltage as the battery SOC increases, but it will only go up to a maximum of 14.4V, and then it will decrease current during absorption to not exceed 14.4V.
You need to set your Full V to 14.4V or less, probably more like 14.3.

But it says when the voltage is higher than the set value it will go to 100%, so if I set it to 14.3v and the scc goes into absorption at 14.4v the monitor will go to 100% right, even if not fully charged?

 

[Spower]

Still need an answer to the above question....I don't understand making it reset to 100% if the batteries are not yet fully charged!

Another thought is.....
maybe it's the wiring going from the controller to the batteries? All RV wires go to one "bus" station then that connects to the batteries. The wire in use is 8g and running about 15 - 20 ft.
I am thinking I would like to try to just run the wires from the controller straight to the batteries. If I do this, and it fixes the issue, what size fuse would I need?

Thoughts on this idea as a possible fix? Otherwise I don't know what else it could be.

 

[MisterSandals]

Thoughts on this idea as a possible fix?

Sounds ridiculous to me.

Otherwise I don't know what else it could be.

What was wrong with this solution? (below)

You need to set your Full V to 14.4V or less, probably more like 14.3.

^^^

 

[Spower]

Sounds ridiculous to me.


What was wrong with this solution? (below)

^^^

Again...I don't understand what setting it to 14.3v will do! Do I want it to reset to 100% if the batteries aren't charged yet? Help me understand this.

 

[MisterSandals]

If your charger only charges to 14.4V and your meter is set to interpret 14.5V as 100%, its never going to read 100%. If you set your meter to interpret 14.3V at 100%, it will read 100% when it gets there. Any load is going to quickly pull this down to 14.0V or lower as the surface charge is quickly pulled.

I know BattleBorn recommends charging this high but your batteries are essentially full at 13.8V with enough absorption time. At voltages above 14V, you're trying to distinguish between 99.90% charged and 99.95% charged.

 

[Spower]

If your charger only charges to 14.4V and your meter is set to interpret 14.5V as 100%, its never going to read 100%. If you set your meter to interpret 14.3V at 100%, it will read 100% when it gets there. Any load is going to quickly pull this down to 14.0V or lower as the surface charge is quickly pulled.

I know BattleBorn recommends charging this high but your batteries are essentially full at 13.8V with enough absorption time. At voltages above 14V, you're trying to distinguish between 99.90% charged and 99.95% charged.

Ah ok, thank you for that! I set it to 14.3v.

Back to the current issue (if it is an issue?)
Right now SCC is in Absorption mode = 14.2v - 14.4v (its a little cloudy sun going in and out), with 15 - 17amps (charging)
Monitor reads = 13.6v and 6 - 9amps (charging)
Again there is no load on the batteries except ~2amps from the inverter that is in standby.

 

[Ampster]

Still need an answer to the above question....I don't understand making it reset to 100% if the batteries are not yet fully charged!

It is a matter of personal preference. Unlike Lead Acid batteries which need to be fully charged to stay healthy, Lithium chemistry do not need to be fully charged to be healthy. In addition, keeping a Lithium battery at a full state of charge can cause degradation. That is one reason I only charge to 3.4 Volts per cell (13.6}. Whether this is 98 or 99.9 percent SOC doesn't matter to me. You could say I have derated my pack from 42 kWh to 40 kWh and I believe that by doing so my pack will last longer.
However I want to use percentages to determine various charge and discharge parameters with respect to time of day. My BMS provides the most accurate SOC if it is reset to 100 percent.

 

[Ampster]

Back to the current issue (if it is an issue?)

It is an issue and one that causes SOC drift because some current meters are slightly inaccurate, especially at low current. That is what causes SOC drift and why I choose to reset to 100 percent often.

 

[MisterSandals]

Back to the current issue (if it is an issue?)
Right now SCC is in Absorption mode = 14.2v - 14.4v (its a little cloudy sun going in and out), with 15 - 17amps (charging)
Monitor reads = 13.6v and 6 - 9amps (charging)

Sounds odd. Can you post a pic of your setup? The many eyes on this forum have found hundreds of issues this way.
Can you post a pic of the Victron app while its charging?

SCC
14.2V x 15A = 213W

Monitor
13.6V x 6A = 81.6W

Is there a (213W - 81W = ) 132W load using this difference?

 

[Spower]

It is a matter of personal preference. Unlike Lead Acid batteries which need to be fully charged to stay healthy, Lithium chemistry do not need to be fully charged to be healthy. In addition, keeping a Lithium battery at a full state of charge can cause degradation. That is one reason I only charge to 3.4 Volts per cell (13.6}. Whether this is 98 or 99.9 percent SOC doesn't matter to me. You could say I have derated my pack from 42 kWh to 40 kWh and I believe that by doing so my pack will last longer.
However I want to use percentages to determine various charge and discharge parameters with respect to time of day. My BMS provides the most accurate SOC if it is reset to 100 percent.

Yup, I just upgraded to the Victron smartsolar 100/50 this week, before this I had the Renogy Rover 40a mppt w/bt, it never went to float, it stayed in boost all day! I think that controller caused some degradation to my batteries. At night when there is no solar the batteries go to 13.24 or 13.25, I use ~3.5 - 4amps running stuff at night, by morning I am at 13.20v.

 

[sunshine_eggo]

Ah ok, thank you for that! I set it to 14.3v.

Back to the current issue (if it is an issue?)
Right now SCC is in Absorption mode = 14.2v - 14.4v (its a little cloudy sun going in and out), with 15 - 17amps (charging)
Monitor reads = 13.6v and 6 - 9amps (charging)

This implies:

1. You have horrible resistance between the MPPT and the battery. Bad connections or thin wires - OR MPPT is malfunctioning. Check MPPT voltage with voltmeter AT MPPT battery terminals and compare to VC reported value.
2. You are using 8-9A of loads. OR the Renogy is not sensing current correctly OR the MPPT isn't reporting current correctly, OR you have something wired wrong.

I think a picture of your system is in order.

 

[Spower]

Sounds odd. Can you post a pic of your setup? The many eyes on this forum have found hundreds of issues this way.
Can you post a pic of the Victron app while its charging?

SCC
14.2V x 15A = 213W

Monitor
13.6V x 6A = 81.6W

Is there a (213W - 81W = ) 132W load using this difference?

I can't get a picture of my setup, batteries are in locked boxes up front, controller and monitor are inside....here is a screenshot of SCC right now