6500EX Not Fully Charging on USB SNU

[John.DS99]

My solar system with 6500EX and 10S panels is set up to reduce my electricity bill.

So I have System Setting 01 SBU and 16 OSO. This way utility doesn't charge the battery.

On a gloomy December day, I realized that the batteries would maintain a low SOC, and I wanted a full charge during crummy weather in case of a utility outage.
So I set 01 USB and 16 SNU. This causes the batteries to charge fully and keeps them fully charged.

At least it should, but it doesn't. It seems to charge the batteries to about 70%SOC.

Can anyone suggest a way to get my system to charge to 100% SOC?

Thanks, Here are all of my System settings for this system and some of my notes.

00 ESC

01 SBU To Save Money 01 SBU 16 OSO To Charge NOW – 01 USB + Program 16 set to SNU

02 60 Amps Maximum Charging Current

03 APL Acceptable Voltage Input APL = 80-140V UPS 90-140V

05 USE Battery Type User Defined, so use programs 26, 27 and 29 to custom charge batteries

06 Ltd No restart after overload ltE Restart

07 Efd “ “ OVER TEMP EFE Restart

09 60 Output Freq (else 50)

10 120 AC Voltage Out Select 110, 120, or 127V

11 20 UEI Max Utility Charging Current 2, 10, 20, … 120 Note this value is added to the load, so 120 means Full output Load + 120 Amps for the battery = TOTAL Output

12 46 Low Voltage that causes switch to Utility AC Input

13 48 Min Voltage that switches back to battery (when on utility and SBU selected)

16 OSO ONLY Solar charges Battery

CSO Solar charges battery if available, else Utility does.

SNU Solar & Utility can charge battery at the same time.

18 bOF alarm racket off

19 ESP Switch back to default screen after timeout FEP

20 LON Backlight On

22 AON Beep if primary source interrupted

23 byd Overload bypass – Transfer to Line if overload occurs

25 FEN Record Fault Mode Fd5 disable

26 56.4 Bulk Charging Voltage

27 54.0 Float Voltage

28 51G ONLY CHANGE IN STANDBY MODE AC Output Mode PAL is parallel There are more like L1 L2 L3 split phases

29 Set to 48 - Low DC Cutoff Voltage

30 Ed5 Battery equalization Disabled

31 33 34 35 36 This is all equalization stuff - not used

37 NfE No reset FSE Reset

41 40 dd5 30A to 150A by 10 symbol dd5 means protection disabled. Maximum Discharging current (FROM BATTERIES AT 54V)

51 LEN RGB LED is on

52 NOF Normal

53 NOF Normal

54 SOL RGB LED effects

55 C01 “ “ Colors

92 dCE disabled On/Off control for 12V DC output (accessory)

93 NFE Disabled Reset Data

94 10 10 minutes data log recorded interval

95 nIN 18? Time setting minutes?

96 18 Time setting Hour

97 27 Time setting Day FIX!! After data download

98 1 Time setting Month

99 24 Time setting Year

 

[WrenchLight]

I'd reduce bulk charging down to 55.9 for LFP 16s battery type and increase float voltage to 55.2. Depending on the BMS settings, if the BMS stops balancing below 3.45V per cell, then that should give you 100%. The BMS should disable charging if any cell exceeds the max voltage. This might be 3.65 to 3.7V. Then the cell has to drop below the recovery voltage, maybe 3.5 before charging is allowed again. Good luck dialing in the settings!

 

[John.DS99]

Thanks, I made those changes. SOC is 64%.
It didn't begin charging.

So I switched to 01 SBU and 16 OSO again and waited a few minutes.
Then I set 01 USB and 16 SNU.

Nothing.

Can I trigger charging somehow?

 

[EG4_Jared]

My solar system with 6500EX and 10S panels is set up to reduce my electricity bill.

So I have System Setting 01 SBU and 16 OSO. This way utility doesn't charge the battery.

On a gloomy December day, I realized that the batteries would maintain a low SOC, and I wanted a full charge during crummy weather in case of a utility outage.
So I set 01 USB and 16 SNU. This causes the batteries to charge fully and keeps them fully charged.

At least it should, but it doesn't. It seems to charge the batteries to about 70%SOC.

Can anyone suggest a way to get my system to charge to 100% SOC?

Thanks, Here are all of my System settings for this system and some of my notes.

00 ESC

01 SBU To Save Money 01 SBU 16 OSO To Charge NOW – 01 USB + Program 16 set to SNU

02 60 Amps Maximum Charging Current

03 APL Acceptable Voltage Input APL = 80-140V UPS 90-140V

05 USE Battery Type User Defined, so use programs 26, 27 and 29 to custom charge batteries

06 Ltd No restart after overload ltE Restart

07 Efd “ “ OVER TEMP EFE Restart

09 60 Output Freq (else 50)

10 120 AC Voltage Out Select 110, 120, or 127V

11 20 UEI Max Utility Charging Current 2, 10, 20, … 120 Note this value is added to the load, so 120 means Full output Load + 120 Amps for the battery = TOTAL Output

12 46 Low Voltage that causes switch to Utility AC Input

13 48 Min Voltage that switches back to battery (when on utility and SBU selected)

16 OSO ONLY Solar charges Battery

CSO Solar charges battery if available, else Utility does.

SNU Solar & Utility can charge battery at the same time.

18 bOF alarm racket off

19 ESP Switch back to default screen after timeout FEP

20 LON Backlight On

22 AON Beep if primary source interrupted

23 byd Overload bypass – Transfer to Line if overload occurs

25 FEN Record Fault Mode Fd5 disable

26 56.4 Bulk Charging Voltage

27 54.0 Float Voltage

28 51G ONLY CHANGE IN STANDBY MODE AC Output Mode PAL is parallel There are more like L1 L2 L3 split phases

29 Set to 48 - Low DC Cutoff Voltage

30 Ed5 Battery equalization Disabled

31 33 34 35 36 This is all equalization stuff - not used

37 NfE No reset FSE Reset

41 40 dd5 30A to 150A by 10 symbol dd5 means protection disabled. Maximum Discharging current (FROM BATTERIES AT 54V)

51 LEN RGB LED is on

52 NOF Normal

53 NOF Normal

54 SOL RGB LED effects

55 C01 “ “ Colors

92 dCE disabled On/Off control for 12V DC output (accessory)

93 NFE Disabled Reset Data

94 10 10 minutes data log recorded interval

95 nIN 18? Time setting minutes?

96 18 Time setting Hour

97 27 Time setting Day FIX!! After data download

98 1 Time setting Month

99 24 Time setting Year

Given that the charging is configured as user-defined, the SOC might not precisely indicate the actual battery charge level. I recommend checking the battery bank with a multimeter to verify if the voltage aligns with the set bulk voltage on the inverter, ensuring an accurate assessment of the charging status. Depending on the battery type, a firmware update and using BMS communication with the inverter could rectify the SOC discrepancy.

 

[Adam De Lay]

My solar system with 6500EX and 10S panels is set up to reduce my electricity bill.

So I have System Setting 01 SBU and 16 OSO. This way utility doesn't charge the battery.

On a gloomy December day, I realized that the batteries would maintain a low SOC, and I wanted a full charge during crummy weather in case of a utility outage.
So I set 01 USB and 16 SNU. This causes the batteries to charge fully and keeps them fully charged.

At least it should, but it doesn't. It seems to charge the batteries to about 70%SOC.

Can anyone suggest a way to get my system to charge to 100% SOC?

Thanks, Here are all of my System settings for this system and some of my notes.

00 ESC

01 SBU To Save Money 01 SBU 16 OSO To Charge NOW – 01 USB + Program 16 set to SNU

02 60 Amps Maximum Charging Current

03 APL Acceptable Voltage Input APL = 80-140V UPS 90-140V

05 USE Battery Type User Defined, so use programs 26, 27 and 29 to custom charge batteries

06 Ltd No restart after overload ltE Restart

07 Efd “ “ OVER TEMP EFE Restart

09 60 Output Freq (else 50)

10 120 AC Voltage Out Select 110, 120, or 127V

11 20 UEI Max Utility Charging Current 2, 10, 20, … 120 Note this value is added to the load, so 120 means Full output Load + 120 Amps for the battery = TOTAL Output

12 46 Low Voltage that causes switch to Utility AC Input

13 48 Min Voltage that switches back to battery (when on utility and SBU selected)

16 OSO ONLY Solar charges Battery

CSO Solar charges battery if available, else Utility does.

SNU Solar & Utility can charge battery at the same time.

18 bOF alarm racket off

19 ESP Switch back to default screen after timeout FEP

20 LON Backlight On

22 AON Beep if primary source interrupted

23 byd Overload bypass – Transfer to Line if overload occurs

25 FEN Record Fault Mode Fd5 disable

26 56.4 Bulk Charging Voltage

27 54.0 Float Voltage

28 51G ONLY CHANGE IN STANDBY MODE AC Output Mode PAL is parallel There are more like L1 L2 L3 split phases

29 Set to 48 - Low DC Cutoff Voltage

30 Ed5 Battery equalization Disabled

31 33 34 35 36 This is all equalization stuff - not used

37 NfE No reset FSE Reset

41 40 dd5 30A to 150A by 10 symbol dd5 means protection disabled. Maximum Discharging current (FROM BATTERIES AT 54V)

51 LEN RGB LED is on

52 NOF Normal

53 NOF Normal

54 SOL RGB LED effects

55 C01 “ “ Colors

92 dCE disabled On/Off control for 12V DC output (accessory)

93 NFE Disabled Reset Data

94 10 10 minutes data log recorded interval

95 nIN 18? Time setting minutes?

96 18 Time setting Hour

97 27 Time setting Day FIX!! After data download

98 1 Time setting Month

99 24 Time setting Year

What are you using to determine your SOC?

 

[wildbillpdx]

On the 6000ex there is an option (21) that sets the SOC level for return to solar/battery:

Set point for transfer back to
off-grid operation if system is
bypassed based on 20

On the 6500 I see it is option 13. Have you tried changing that? On the 6000ex with EG4 batteries it is presented as percentage of charge. I have mine set to 95% since it never seems to reach 100%.

 

[John.DS99]

What are you using to determine your SOC?

I do have a Victron Smartshunt on that battery bank. The voltage was mid 53's. I am not completely confident that was set up properly because it never fully charges here in the winter and I only got it recently. I can log the data next time it recharges. Thank you, good thinking.

 

[John.DS99]

On the 6000ex there is an option (21) that sets the SOC level for return to solar/battery:

Set point for transfer back to
off-grid operation if system is
bypassed based on 20

On the 6500 I see it is option 13. Have you tried changing that? On the 6000ex with EG4 batteries it is presented as percentage of charge. I have mine set to 95% since it never seems to reach 100%.

In the above settings file I have my comments included,
I said
13 48 Min Voltage that switches back to battery (when on utility and SBU selected)

Translation - Program 13 is set to 48V. This is the voltage that returns the unit back to battery mode if it is running on line mode (utility).

Maybe I'm not understanding what the manual says.

At any rate I know it was in the mid 53s on voltage when it stopped charging. I'm pretty sure Adam got it right when he said my SOC may have been incorrect.

All of this discussion has helped. Thank you all.