Hi Everyone. Here comes a totally new green one!

We have an Axpert 8K48V installed with  2 Dyness 48V/75A LiFe batteries installed. The  batteries  are wired up  in parallel. There are 4 solar panelsystem connected  to the  inverter to  charge  the  batteries  during  daylight  hours.  

Presently, the system works  - the PV charges  tte battery which  run the  load. At night the battery  is on Bypass and Escom charges the battery The problem  is - only ONE batter, the Master is charged.  The installer said  that  once the Master is fully  charged,  the Slave will  start acceptin a charge. This is the  4th day since  commissioning and the  Slave still  has not  been charged.  The installer has been  too busy to  come by.

Please Brainstrust, what needs to be  done to get  the  Slave working? 

Awaiting  anxiously for  some  guidance .

Regards 

Sam the  Ham

12 hours ago, Sam the Ham said:

The installer said  that  once the Master is fully  charged,  the Slave will  start acceptin a charge.

I don't know the Dyness battery modules, but that doesn't sounds right to me.

I would try to disconnect the master, and see if the slave on its own is working. But first wait for the master to become full, then hopefully when the slave is full, parallel them again and see if that fixes the problem. 

What is the power rating of your panels? 4 panels sounds a bit light for your system.

Also, 4 panels is possibly too low a voltage to drive the solar charge controller properly.

What PV voltage do you see near midday?

Do you see any battery charging at say 8am and 4pm?

I have a few Dyness 3.6 kW batteries in my setup. All of then charge and discharge at the same time so what you're experiencing doesn't sound right. Are you using CAN to communicate between the Axpert and the master battery and is there a network cable between the master and slave? Also check that the second battery is actually switched on. I didn't realise initially, just flicking the power button to on doesn't mean the battery is active. I had to hold the SW button down before some of the slaves came on and started to charge.

Thanks to Topp, Coulomb and Paul Greef.

Yes, there is a LAN Cable connecting the two batteries.  Paul may have a point.  I will go and activate the switch again for more than the 2 seconds usually mentioned...  Just checked.  It is not a press button switch but a 0/I toggle and it is On.

I've tugged on the LAN cables and they are securely attached.  Was a bit busy during the day so did not check daytime PV Voltage or current delivered.  

Unfortunately the User Manual is a tiny booklet - 1/2 of an A5 page and i'm getting to the stage of being visually challenged.  I think it may be a Menu setting that was missed.... which one ??

Thanks for all the help so far - very much appreicated.

The installer came in this afternoon...shaking his head !  He checked the system and went throught he set up and still no charge going to the Slave.   He made a 'phone call and pulled out the Lan Cable between the Inverter and Master Battery....all of a sudden the Slave showed that it was taking a charge !  Now we have to determine if the cable is at fault.  Installer is taking the cable back to the supplier of the battery....so we will only find out later.

Is the Lan cable not an essential to monitor the state of the batterioes??

 

Thanks all.  Will report back.

Sam the Ham

 

7 hours ago, Sam the Ham said:

Is the Lan cable not an essential to monitor the state of the batterioes??

It's good to have it there long term, but a week without it is unlikely to cause any problems. You won't have an accurate SOC reading while the cable is missing.

Hi Coulomb

Apparently the supplier says that the long LAN cable is not the right one.  They will get another one across to us next week.  As far as I know, it is part of the BMS.

Both batteries today are fully charged.  The LEDs are showing maximum.  The Inverter display shows that the house is operating off the batteries but the Solar Panel symbol still flashes - has been all of yesterday afternoon and today.  I presume that indicates that the solar panels were not part of the charging although I had set Menu 16 to CSO - solar has priority charging, in its absence, Utility takes over. so not sure why this is the case.  BTW the 4 panels are 250W each.

As a test to check the duration of the batteries, we have switched the Utility out of the circuit and the house is running entirely off the batteries, even the fridge.  The kettle, which we use often, also works off the batteries.   I have noted the time we did the switchover and will observe the length of time the batteries will hold out.

Thanks for being there to guide me along ! 

Sam the Ham

 

 

 

14 hours ago, Sam the Ham said:

but the Solar Panel symbol still flashes - has been all of yesterday afternoon and today.  I presume that indicates that the solar panels were not part of the charging although I had set Menu 16 to CSO - solar has priority charging, in its absence, Utility takes over. so not sure why this is the case.  BTW the 4 panels are 250W each.

Ah. Assuming that you have the Axpert Max 8 kW, 4 panels in series is not enough voltage. These high voltage SCCs seem to be need 6 panels minimum to be really happy, 5 might do most of the time. When the solar panel icon is flashing, it means the voltage is too high or too low, and likely is  not generating any power, or perhaps vastly reduced power. Also, 4 250 W panels (1 kW total) is very small for an 8 kW inverter. You'll struggle to fill the battery with solar, unless you are vastly under-utilising the inverter.

If you actually have a model with a 145 V absolute max SCC, then 4 panels, if all in series, is far too high a voltage.

What is your panel voltage when flashing?

Hi Coulomb  The inverter is charging the batteries with the source being Escom.  When the batteries are full, they take over and supply the house.  However, the Solar symbol still flashes.  The installer made up his own LAN cable but that did not change anything - the solar symbol is still flashing.

What I found after the installer had left is that there is no voltage or current coming from the solar panels.  Perhaps it has not been connected up to the Inverter - I would think this is the likelihood....installer coming back next week.

Regards

Sam the hAM

 

12 minutes ago, Sam the Ham said:

What I found after the installer had left is that there is no voltage or current coming from the solar panels.  Perhaps it has not been connected up to the Inverter - I would think this is the likelihood....installer coming back next week.

I hope you are going to present him with an invoice for your trouble shooting.

OK - after waiting on the installer, he finally pitched and checked the solar panels.  He came down with a cable that was ostensibly connecting the panels IN PARALLEL that a previous installer had put in.   There was an adapter that he removed as well.  The panels are now in series and delivering 100V - dropping down to 97V occasionally.  

 That done he made the changes to the inverter and the solar symbol has now stopped flashing.  The LCD panel indication now shows that Utility and the Solar panels are charging the batteries.  Batteries reached full in quick time.  House worked off the batteries the entire afternoon and evening, dropping down to 2 LEDs (50% level) towards 21h00.   That was yesterday.

This morning 07h00, the battery was down to 1 LED and charging was from both Escom and Solar (sun was hardly up ?).   This charging combination carried on ALL DAY with the battery showing just 2 LEDs.  It was only towards 5.00 p.m. that it went to 3 LEDs and still charging and Escom was ByPassing the system and powering the house.  By 19.30 there were 4 LEDS but still charging.  Ten minutes ago - 21.00 the battery is fully charged and we are now on batteries.

Everything appears to be working normally now.  However, the nagging question is - why did it take all of this morning and afternoon for the batteries to charge to 50% ?   Looks like we have one more hurdle....

Thanks all for your input and suggestions.

5 hours ago, Sam the Ham said:

why did it take all of this morning and afternoon for the batteries to charge to 50% ?

We need data.

Was the PV icon solid all morning?

What is the nominal power rating for your 4 panels? Unless they're really giant panels, it will take many hours to charge a 7.5 kWh battery while also running loads.

What sort of loads were you running that day?

What are the values for settings 02 and 11? (Total and utility maximum charge current).

What sort of PV charge current are you observing during the day? Give the approximate AC load at the time of the measurements.

We'll probably need more data, but this is a start.

Edited April 16, 20215 yr by Coulomb