Solar charges, SOC goes down?

[Bmarler]

no need to dig further Leo, those voltage readings are good.
did you see my question regarding the negative connection?

 

[LeoKa]

the shunt is very simple to hook up. the b-minus goes to the battery negative, and nothing else. the p-minus goes to your house negative buss where everything else is hooked up.
then you need a single small battery positive wire to the b-plus terminal for voltage readings.

Hmm, mine is the opposite way. Shall I turn it around and see?

 

[Bmarler]

Hmm, mine is the opposite way. Shall I turn it around and see?

yes, absolutely. it must be hooked up in the proper direction.

 

[Bmarler]

Yes, it was discussed earlier. I believe I have it correctly.

i wish i'd have looked closer at this picture. it clearly shows the shunt hooked up backwards. this should solve the problem.

 

[LeoKa]

I still cannot believe my eyes, but it seems to be working properly.
Thanks for All of You for the patience with me. It was a learning curve for sure.
Now if you could just teach me how to repair my dead inverter... Lol,

 

[LeoKa]

I suspect the MasterShunt was incorrectly connected, as well. The drain was there with that one already.

 

[Bmarler]

I suspect the MasterShunt was incorrectly connected, as well. The drain was there with that one already.

ok then, glad to see it's working now. that'll be a great solar array in summertime, you'll make your daily power easily. i know with my .75kw array i am floating by midday when the sun's out. it's so cool to look at that free power coming in as a drink my coffee in the morning.
you're most likely right about the other shunt. it was showing a drain, but it was not reporting accurately as it wasn't hooked up correctly.
too bad this was an expensive lesson, but now you can go get that bigger inverter you wanted.

 

[LeoKa]

too bad this was an expensive lesson, but now you can go get that bigger inverter you wanted.

It is. Not the first one.
I am sure there will be more....

The new inverter has been ordered.

https://www.renogy.com/rego-3000w-12v-pure-sine-wave-hf-inverter-charger-split-phase-design/

It is true, the batteries were charged in couple hours when sunny, even in this low angle area. I have not tested it yet in the summer months. If I can disconnect the shore charging and the solar can handle the basic house load, while I am away for a month; I will consider it worthwhile with all the hassle, damage, and expense. I learned a lot and as they say; There is always a first time....
Thanks again!

 

[twistedtree]

I did. Soon after I saw your message. No luck. It is dead.

Sorry to hear that. Hopefully the MasterShunt is OK.

 

[LeoKa]

I am ready to pull my hair out. The problem is back, even though nothing has changed. There is a drain again on the monitor. Apprx. 1.4 amp is being pulled out, so the SOC is going down slowly.
The solar controllers are off. It is dark now.
Battery bank shows 13.3V and the SOC now is 98%.
I disconnected shore power AC, to trigger a new charge sequence. MasterVolt goes through it, but fairly soon it gets to Float.
I know this is a small draw, not as much as before, but still it is draw. Plus, the charger should come on, if the SOC goes down.
Let's see what happens in the morning? Will the CombiMaster charge kick in, at one point?

 

[LeoKa]

Silly questions idea and solved some of this for me, was to TURN OFF on LOADS, and Charge the bank. Then Zero out or reset the Shut, on Victron has Reset for my RV and my magnum Monitor on our Boat has Zero out.
Basically what I have found this clears the data and starts with a full charged back with NO Load then when put your load back in after reset/zero out you have clean base line and get much more SOC just my 2 cents.

I just tried what you suggested. The battery bank is fully charged, stays at 13.3V and CombiMaster finished the charging.
I turned off all 12V load. Disconnected the battery monitor.
Once I connect the monitor back, there is still drain of 0.2 amps, even without any load connected. Not much I know, but it is bringing down the SOC slowly.
Perhaps the CombiMaster is using this, I don't know?
I turned the load back on and a bunch of 12V lights. Now the draw is 6.1 amps steady. We'll see what happens?

 

[LeoKa]

Here is the software I can use for the CombiMaster charger/inverter. It shows that it should go back to Bulk mode when it goes down to 13.25V.
The monitor tab shows that the battery voltage is between 13.4-13.8V and almost no amps used.

The battery monitor shows for the battery bank 13.27V and SOC 93.1% using 6.6A drain.

Which one do I believe now?

 

[SteveK]

Leo. 0.2A, 1.4A is nothing. Are you not aware that the electronics that control the charge/discharge all need power to operate even with nothing else on load. even the mppt with no sun. The readouts will consume small milA.
Dont stress over such small numbers.

 

[LeoKa]

Leo. 0.2A, 1.4A is nothing. Are you not aware that the electronics that control the charge/discharge all need power to operate even with nothing else on load. even the mppt with no sun. The readouts will consume small milA.
Dont stress over such small numbers.

Understand.
Am I correct, if I think at one point the charging should resume?
I don't know what the required SOC/Voltage for this to happen, but should it happen?

 

[SteveK]

Understand.
Am I correct, if I think at one point the charging should resume?
I don't know what the required SOC/Voltage for this to happen, but should it happen?

Your system re-starts bulk charging when voltage drops below 12.8v (default) and adjustable from 12-15v

 

[twistedtree]

Understand.
Am I correct, if I think at one point the charging should resume?
I don't know what the required SOC/Voltage for this to happen, but should it happen?

It's on the screen that you posted. You have Float set to 13.5V, so as long as there is AC power to the Combi, it should hold the batteries at approximately 13.5V. Right now, based on the status screen, the batteries are at 13.4V. I don't know how precise the voltage regulation is in the Combi, but for now would assume it is working correctly in Float mode.


The screen also shows that it will return to Bulk when the batteries drop below 13.25V. So of you disconnect shore power, then later reconnect, it will only go to Bulk charging if the batteries are below 13.25V. Otherwise it will return to Float.


What I have described is "typical" charging, but some vendors have variations so read the section in the manual that describes how the Combi works. It's a much better source for answers about how the product operates than we are.

 

[twistedtree]

Further, your status screen shows that the charger is in Float mode. The float setting is 13.5V and the battery is at 13.4V, so charger regulation appears to only be within 0.1V of the target setting.


If this using the MasterShunt? If do, I would expect the Combi to be getting it's voltage reading from the shunt. Otherwise it will be sensing it internal to the Combi and it will vary based on DC current, both charging and loads. It doesn't look like the Combi had a remove voltage sense of its own.


Also, the DC current on your status screen is the Combi's DC current, not the net current into/out of the battery. It's important to understand the difference. You have the Combi charging or draining the battery, solar chargers sometimes charging, and varying loads. Depending on where you meter, you will see different things. The sum total is what's going into/out of the battery, and the whole point of the MasterShunt is to measure that specifically since it's the only thing you can calculate SOC off of.

 

[SteveK]

I do not know what software gave you those two screen shots you posted 162. I do not know if you are using that software, it does not appear to give you a choice for rebulk. In post 165 I gave you what the manual says your charger is set for by default.

 

[LeoKa]

If this using the MasterShunt?
since it's the only thing you can calculate SOC off of.

No, the MasterShunt is removed. I only use the battery maker's monitor/shunt.

 

[LeoKa]

I do not know what software gave you those two screen shots you posted 162.

The software is from MasterVolt. That is available for certain settings and monitoring. It uses Masterbus network to talk to the devices.

 

[LeoKa]

It's on the screen that you posted. You have Float set to 13.5V, so as long as there is AC power to the Combi, it should hold the batteries at approximately 13.5V. Right now, based on the status screen, the batteries are at 13.4V. I don't know how precise the voltage regulation is in the Combi, but for now would assume it is working correctly in Float mode.

I don't know how accurate the software readings are now, since the MasterShunt is out of the loop. Whatever the Combimaster is reading, it should come from its internal setup. The battery monitor I have now and posted pictures of it earlier, is from the battery manufacturer, which is not Mastervolt.
This monitor shows a different voltage of 13.3V all night, while the software from Mastervolt shows between 13.4-13.8V. It moves up and down.

 

[SteveK]

OK, How did the rebulk default setting go from 12.8 to 13.25 as displayed. The 13.25 displayed does not appear to be resetable.

BTW, were you able to order that 50A Mastervolt?

 

[rslifkin]

I don't know how accurate the software readings are now, since the MasterShunt is out of the loop. Whatever the Combimaster is reading, it should come from its internal setup. The battery monitor I have now and posted pictures of it earlier, is from the battery manufacturer, which is not Mastervolt.
This monitor shows a different voltage of 13.3V all night, while the software from Mastervolt shows between 13.4-13.8V. It moves up and down.

I wouldn't trust any SOC indications from the Combimaster without a shunt, as it only knows about its own power flow, not any power supplied or used by other devices. The voltage indication should still be accurate though.

 

[LeoKa]

As of now, the battery monitor shows SOC 73.9 down from the SOC yesterday afternoon when it was 100%. The voltage on this monitor is still 13.3V.
The solar panels are just ' waking up ' now, so some charge will go into the batteries soon.

I admit, I do not completely understand what SOC is? I thought it was like a value of energy storage inside the batteries, but I see now that is not correct.
My concern was last night that the batteries will be sucked down overnight for an unknown reason, even though the shore power AC was on and Combimaster should have started the charging. I was wrong.
I see now that the charging will happen when the voltage reaches the set voltage and has nothing to do with the SOC.

 

[LeoKa]

OK, How did the rebulk default setting go from 12.8 to 13.25 as displayed. The 13.25 displayed does not appear to be resetable.

BTW, were you able to order that 50A Mastervolt?

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.

 

[SteveK]

OK, once you get the new inverter/charger there will be new parameters/settings to work with.
For now, I asked how the preset Mastervolt 12.8v default was changed to 13.25. OR was it changed? Maybe it was just a sample picture and not an actual readout. You should use the programming for the inverter/charger to set within the allowable.

 

[LeoKa]

For now, I asked how the preset Mastervolt 12.8v default was changed to 13.25. OR was it changed? Maybe it was just a sample picture and not an actual readout. You should use the programming for the inverter/charger to set within the allowable.

It was not changed. As I said earlier, this could be a setting from the ' lithium ' charging profile Mastervolt allows. I cannot change it.

 

[SteveK]

Leo, have you read the Renogy manual? Link here
Also are you aware this is an automotive grade inverter/charger.

 

[LeoKa]

Leo, have you read the Renogy manual? Link here
Also are you aware this is an automotive grade inverter/charger.

Yes, I have.
It does have the 50A passthrough feature, which I was looking for. Also have Bluetooth, which I wanted.
My inverter/charger is located in the salon, inside a cabinet, with built-in ventilation for airflow. The lithium batteries are there, too, since ER is not the best place for lithium. My ER is hot. The engine is dry exhaust, so not the best for these batteries. This solution is for the need to have the charger as close as possible to the batteries.
Besides, they make marine stuff, too:
https://www.renogy.com/solution/marine/

 

[LeoKa]

The sun is coming up now and the solars are putting in 14.6 amps into the lithiums. SOC is rising.