Solar charges, SOC goes down?

[LeoKa]

They also have this thing:
https://www.renogy.com/open-box-renogy-one-core/
This allows me to monitor the charges remotely, even if I am out of the country for a longer period. It will come handy.

 

[twistedtree]

Yes, I did order it. It is coming. Not MasterVolt. Renogy brand.
I also want all the wires/cables ready, before I do any replacement, so it will not be hooked up for few weeks.

The software shows the preset values for Lithium batteries in the CombiMaster. Those cannot be changed. This setting puts the re-bulk value to 13.25V. I have not checked, if this charger has a ' user defined ' option, and it does not matter anymore. I will look into this with the new charger.

The battery monitor shows 0.5A going into the battery bank now. It is still cloudy outside.

Yet again, I am really confused. Did you get the Combi working again after the reverse polarity event? What inverter is in the system, if not the broken Combi or some replacement?

 

[SteveK]

Yet again, I am really confused. Did you get the Combi working again after the reverse polarity event? What inverter is in the system, if not the broken Combi or some replacement?

Last I heard it was charging but not inverting so a renogy replacement is on the way.

 

[SteveK]

Yes, I did order it. It is coming. Not MasterVolt. Renogy brand.
I also want all the wires/cables ready, before I do any replacement, so it will not be hooked up for few weeks.

The software shows the preset values for Lithium batteries in the CombiMaster. Those cannot be changed. This setting puts the re-bulk value to 13.25V. I have not checked, if this charger has a ' user defined ' option, and it does not matter anymore. I will look into this with the new charger.

The battery monitor shows 0.5A going into the battery bank now. It is still cloudy outside.

But I am sure the manual I linked does allow changes, so now I must assume the software you have is not for that model Mastervolt. Mute as you are replacing it.

 

[LeoKa]

Yet again, I am really confused. Did you get the Combi working again after the reverse polarity event? What inverter is in the system, if not the broken Combi or some replacement?

There is no Inverter at this point.
The charge section was always working on the Combi. Unfortunately, the inverter part is dead, even after reversing the polarity on the DC cables.
The boat is running from AC shore-power using the pass through feature.
DC charging is on, but not kicked in, since the batteries did not go down on voltage enough. CombiMaster charging comes on only when a pump or similar starts and the draw is significant. Only for short time and after some charging it goes to standby.
The solars are charging nicely this morning. The sun is out and the panels are pushing 32A in right now. The SOC is 100% now.

 

[twistedtree]

Last I heard it was charging but not inverting so a renogy replacement is on the way.

OK, I missed that. What evidence do we have that it's actually charging? I see 0A in the software display, and a programmed float voltage of 3.5V. With that it should be producing some current, at least some times. I would assume the charger is broken until proven otherwise.

 

[SteveK]

OK, I missed that. What evidence do we have that it's actually charging? I see 0A in the software display, and a programmed float voltage of 3.5V. With that it should be producing some current, at least some times. I would assume the charger is broken until proven otherwise.

post 185

With LFP you can have zero current and volts show float voltage. I see it on mine

 

[LeoKa]

But I am sure the manual I linked does allow changes, so now I must assume the software you have is not for that model Mastervolt. Mute as you are replacing it.

Yes, changes are possible using DIP switches. In there, you can choose different battery models, but the settings are fixed. If all the DIP switches are OFF, you can make changes in the MasterAdjust software, but only for Flooded batteries.


From the Manual:

5.1 DIP switch settings
Use a small screwdriver to carefully set the required settings.
In a CZone network:
DIP switches 1 and 2 OFF.
DIP switches 3 to 10 must match the unique address used in
the CZone network; the dipswitch (see the CZone
Configuration Tool Instructions manual). At least one of DIP
switches from 3 to 10 must be ON.
In a MasterBus network:
DIP switch 1 ON.
DIP switch 2: ON = MasterBus Powering on
OFF = MasterBus Powering off.
Figure 6. DIP switches (factory settings)
DIP switches 3 to 5 are used for battery type selection:
DIP switch 3 4 5
Configurable via MasterAdjust (Flooded)1 0 0 0
Flooded (fixed) 0 0 1
AGM (fixed) 0 1 0
Gel (fixed) 0 1 1
MLI (fixed) 1 0 0
Constant voltage (13.25V)2 1 1 1
If DIP switches 3, 4 and 5 are OFF,
the settings suit a Flooded battery
but can be changed in MasterAdjust.
2 Constant voltage has no temperature
compensation.

 

[twistedtree]

post 185

With LFP you can have zero current and volts show float voltage. I see it on mine

Agreed, but his actual voltage is below the float voltage, so I would expect to see the charger providing some current to maintain 3.5V. And his 3rd party SOC meter reports an even lower voltage. Of course we need to allow for some discrepancies between the different meters, and that might account for it. I'd just like to know how it was concluded that the charger is actually working. Maybe it is, but after the reverse polarity event it's highly suspect. Have we seen positive, non-solar current going into the battery, and if so, measured where and how? Has the MasterAdjust software reported positive current coming out of the charger? Sorry to dwell on this, but so many of the past observations and information has been incorrect or misinterpreted.

 

[SteveK]

Please look on page 30 same manual for re bulk.
Now I see you do not have a remote page 35 that can change internals but fact is 12.8v or less restarts bulk charging as default

View attachment 10000015714_17UserManualCombiMaster120Vseries.pdf

 

[LeoKa]

Sorry to dwell on this, but so many of the past observations and information has been incorrect or misinterpreted.

Your question is valid. Honestly, I do not know. I have not seen charging from CombiMaster, because I did not pay attention. It is possible that the charging is malfunctioning. What I know, if I turn off the shore AC and back on, it will trigger charging sequence on the CombiMaster. It goes through the bulk,abs,float and stops. The led lights are following this sequence on CombiMaster and at the end the LED is on the Float charge.

Right now the solars are still charging, so I cannot see anything from the CombiMaster.

 

[LeoKa]

Please look on page 30 same manual for re bulk.
Now I see you do not have a remote page 35 that can change internals but fact is 12.8v or less restarts bulk charging as default

View attachment 143433

Yes, you are correct. I see the manual. 12.8V restarts the bulk.
Changes are available, but only for flooded batteries. Not for lithium.

 

[LeoKa]

Have we seen positive, non-solar current going into the battery, and if so, measured where and how? .

After the solars stopped, I was watching the battery monitor. I could see no charge from anywhere, but couple hours later, the draw started and the monitor showed minus amperage. This told me that the batteries were providing DC to the house.
This was the reason why I started asking questions about the re-bulk voltage starting point. On flooded batteries it is 12.8V in the MasterAdjust software. On lithium settings it is 13.5V but I did not see the battery voltage level that low.
The batteries themselves have a voltage display and it was always on 13.3V, so it is not very useful. The monitor can show smaller voltage and it was dancing around 13.31-13.30V this morning.
So, there is no way to say that all these measures are accurate or in sync. Again, the CombiMaster lights show that charging is on. Does it really charge anything? I do not know. Perhaps I could disconnect the solars and see how low the batteries need to go down, before CombiMaster start charging, if at all.

 

[rslifkin]

If the Combimaster is showing that it's in float but not putting out any power, and it's also showing voltage near the expected float voltage even when the batteries are lower, I'd suspect that the Combimaster is charging internally, but not actually putting out power to the batteries (possibly due to a blown fuse or something in the unit).


When it's in float and trying to hold 13.5 volts, I'd expect it to output power to maintain 13.5 volts, not to just let the voltage drop to the re-bulk threshold and then start charging.

 

[SteveK]

Disconnect solar input to mppt at night in dark, do not disconnect at battery daytime as the mppt will blow.

 

[LeoKa]

If the Combimaster is showing that it's in float but not putting out any power, and it's also showing voltage near the expected float voltage even when the batteries are lower, I'd suspect that the Combimaster is charging internally, but not actually putting out power to the batteries (possibly due to a blown fuse or something in the unit).


When it's in float and trying to hold 13.5 volts, I'd expect it to output power to maintain 13.5 volts, not to just let the voltage drop to the re-bulk threshold and then start charging.

This makes sense. I think you are correct. The CombiMaster is toast either way and needs repair. Like I said, I ordered a new inverter/charger, so I suspect with the new one things will go back to normal.

 

[LeoKa]

Disconnect solar input to mppt at night in dark, do not disconnect at battery daytime as the mppt will blow.

OK, I will do this tonight. Let's see what will happen till morning?

 

[twistedtree]

Your question is valid. Honestly, I do not know. I have not seen charging from CombiMaster, because I did not pay attention. It is possible that the charging is malfunctioning. What I know, if I turn off the shore AC and back on, it will trigger charging sequence on the CombiMaster. It goes through the bulk,abs,float and stops. The led lights are following this sequence on CombiMaster and at the end the LED is on the Float charge.

Right now the solars are still charging, so I cannot see anything from the CombiMaster.

Are you only observing the LEDs, or is some meter showing charge current from the Combi?

 

[twistedtree]

When it's in float and trying to hold 13.5 volts, I'd expect it to output power to maintain 13.5 volts, not to just let the voltage drop to the re-bulk threshold and then start charging.

Right, that's the whole point of Float.

 

[LeoKa]

Are you only observing the LEDs, or is some meter showing charge current from the Combi?

Both.
The MasterAdjust software is my monitoring option on the CombiMaster side. The software shows the same data what I posted earlier. It never changes.
Just now, the fan came on and the led lights showed charging process, but the software does not change. The fan was running for few minutes and when the led reached float charge, it turned off after a minute.
I don't know what triggered this charge process, because nothing has changed in the house load. I suspect that the inverter/charger is malfunctioning.

The battery monitor is not connected to the Mastervolt devices, and only shows me the solar data.

 

[LeoKa]

When this recent fan activity, or ' ghost charging ' started, I disconnected all solar charging. The voltage/amperage turned to minus, meaning instead of charging, there was a draw from the batteries.

The CombiMaster fan was on, as I described, but I did not see any charging on it. Only the led lights and the fan noise.

Now that the CombiMaster finished what it was doing, I turned the solars back and the charging of batteries continued. At least that what the battery monitor showed.

 

[NoRain]

Do you have a clamp-on multimeter? If not, get one. You need to be wayy past the point of guessing or assuming what’s going on by now. Something like this would suffice for the time being https://a.co/d/1i0PeFb. You can then positively identify what currents are flowing from or to where.

 

[LeoKa]

Do you have a clamp-on multimeter? .

Yes.

 

[Bmarler]

I wouldnt spend any time worrying about the combimaster. It’s toast. Solar panels are doing what they’re supposed to be doing.
Leo, did you reach 100% soc before nightfall?

 

[LeoKa]

I wouldnt spend any time worrying about the combimaster. It’s toast. Solar panels are doing what they’re supposed to be doing.
Leo, did you reach 100% soc before nightfall?

I fear that you are correct on the CombiMaster.

I did reach 100% SOC with solars in couple hours. I do agree they work as they suppose to. At one point I could see 42A coming down from the panels, which is fairly good in the low angle November sunlight. I think the bifacial panel helps, because the low angle light can sneak under the panels.

I am posting few pictures about the amps I measured on the DC line. No charge from the solars. All turned off. No monitoring from the battery monitor, either.
A pair is showing the CombiMaster DC connection without any load in the house, + and - cables.
Next pair is showing the + cable going directly to the distribution panels below. One with and one without load. The load was 4 small LED ceiling lights only.
Another pair is showing the amps before the shunt.
The last photo is the CombiMaster + DC cable with the same load.
You can see there is a difference what goes to the breakers from the inverter/charger and before the CombiMaster.

I am leaving the solar system off for now. I want to see, if the CombiMaster will do anything, once the batteries go down more. At this rate, it might take a long time, before anything changes in the batteries. The battery voltage display shows 13.3V since yesterday. With the low amp load, it will not go soon to whatever the CombiMaster thinks it should start charging. If at all. The CombiMaster did start the fan few times last night and there was LED charging sequence, but there was no load on the DC side, so I am not sure, if that was a maintenance process, or the CombiMaster is confused?

 

[Bmarler]

it's likely the combimaster is firing up at a timed interval to see the condition of the bank and determines if it needs to turn on the charge output. it senses the voltage and sees that the bank hasn't reached a threshold for recharge. i suspect that if the charger sensed a low voltage situation it would indeed start charging.
if you're impatient, turn on some dc loads (with the solar turned off) and try to get the batteries down a bit faster.
it's encouraging that you can easily reach 100% soc in these low light situations. mine will in summer, but not now. but being able to make my daily needs in summer is what i cared about as i can stay on the hook indefinitely without starting the genset.

 

[Bmarler]

the amp draw you see is likely just parasitic load from the charger electronics, and whatever else you have that needs to be kept alive. (stereo, or other electronics that are always connected to dc power)

 

[Bmarler]

one more observation. does that meter show direction of power flow? some pictures show a minus sign under the dc designator before the numerical readout. just wondering.

 

[LeoKa]

one more observation. does that meter show direction of power flow? some pictures show a minus sign under the dc designator before the numerical readout. just wondering.

I suppose it does. I need to check the manual. The photos with - DC are battery connections, before and after shunt. It must a draw going to the distribution panels, where some usage should be present.

The photos without - DC, just plain DC, are the CombiMaster wires.

 

[LeoKa]

the amp draw you see is likely just parasitic load from the charger electronics, and whatever else you have that needs to be kept alive. (stereo, or other electronics that are always connected to dc power)

Yes, that makes sense.