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Need a little guidance

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wp12kw

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Jun 6, 2022
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Happy New Year everyone,
I need a bit of guidance on settings for an off grid shop system. My equipment is a Rover 40amp SCC, 8 EVE LF280k in series for 24v using Xiaoxiang BMS, and a Giandel 4000w 24v inverter. I have 12 Stion STL-145 panels in 4P3S configuration for power.
The cells were top balanced to 3.65v.
The attachments are screen shots of the current settings.
I keep getting over voltage disconnects and hi voltage shutdown of the inverter.
Currently the load is 2 chest freezers and some led lights.
I could use some guidance.
 

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Please share the details of the charge profile on your charger(s).
 
Overvoltage to me says you exceeded to input DC voltage of the inverter. I’m guessing that 32 VDC is the cutoff, but your BMS shows 29volts max.

Is there a point where it shuts off, freezers kick in?

I think two chest freezers may exceed the inverter limit if they kick on at ounce.
 
wp12kw said:
I'm not exactly sure. Have seen so much confusing information about settings. Noob ignorance.
Click to expand...
I can't help you anymore than I already have without these details.
At least you know where to look next.
 
John Frum said:
I can't help you anymore than I already have without these details.
At least you know where to look next.
Click to expand...
If I understand correctly, the Rover is set for 24v, Li battery. No adjustment can be made unless battery is set to “user”. The panels are providing around 70v @ 8a depending on irradiance. The rover is limited to 100v.
 
Last edited:
wp12kw said:
If I understand correctly, the Rover is set for 24v, Li battery. No adjustment can be made unless battery is set to “user”.
Click to expand...
Please provide a product link to your solar charge controller and I will see what can be done.
 
wp12kw said:
Rover Li 40 Amp MPPT Solar Charge Controller
Click to expand...
Are you using the load ports on solar charge controller?

Try the following and see if they work for you.

set the battery profile to user
set the following parameters

over_voltage_warning=29.2
equalization_voltage=18
boost_voltage=28
float_voltage=26.4
under_voltage_warning=24.8
under_voltage_recovery=25.6
low_voltage_disconnect=24
equalization_duration=0
boost_duration=2

page 28 of https://www.renogy.com/content/RNG-CTRL-RVR40/RVR203040-Manual.pdf
 
Last edited:
make these changes to the bms config

#under protections
batt_over_voltage_trigger=29200
batt_over_voltage_release=27000

#under capacity configuration
total_cycle_capacity=280000
 
Nothing on the load ports.
I'll change the settings and post results.
 
wp12kw said:
I have 12 Stion STL-145 panels in 4P3S configuration for power.
Click to expand...
This is interesting. Is there a reason you parallel the 4 panels before putting in series?
145 Watt Solar Panel - Specs:

  • Nominal Power, PMAX(W) - 145 Watts
  • Module Efficiency (%) - 13.3%
  • Vmpp (V) - 61
  • Impp (A) 2.38
  • Voc (V) - 79.6
  • Isc (A) - 2.68
That comes out as 238.8Voc (without temp compensation)

How has this not killed your Renogy Rover?

Max. Solar Input Power 12V/520W, 24V/1040W
The Rover MPPT charge controller can work with standard off-grid 12/24V solar panels with high voltage or multiple panels with voltage up to 100V.
 
MisterSandals said:
This is interesting. Is there a reason you parallel the 4 panels before putting in series?
145 Watt Solar Panel - Specs:

  • Nominal Power, PMAX(W) - 145 Watts
  • Module Efficiency (%) - 13.3%
  • Vmpp (V) - 61
  • Impp (A) 2.38
  • Voc (V) - 79.6
  • Isc (A) - 2.68
That comes out as 238.8Voc (without temp compensation)

How has this not killed your Renogy Rover?

Max. Solar Input Power 12V/520W, 24V/1040W
The Rover MPPT charge controller can work with standard off-grid 12/24V solar panels with high voltage or multiple panels with voltage up to 100V.
Click to expand...
they are actually set up in 12P (3 groups of 4) to stay under the 100v 40a limit of the Rover.
 
wp12kw said:
they are actually set up in 12P (3 groups of 4) to stay under the 100v 40a limit of the Rover.
Click to expand...
That doesn't sound right.
12p is actually 1s12p, would be 12 groups of 1 panel each.
 
Last edited:
wp12kw said:
Happy New Year everyone,
I need a bit of guidance on settings for an off grid shop system. My equipment is a Rover 40amp SCC, 8 EVE LF280k in series for 24v using Xiaoxiang BMS, and a Giandel 4000w 24v inverter. I have 12 Stion STL-145 panels in 4P3S configuration for power.
The cells were top balanced to 3.65v.
The attachments are screen shots of the current settings.
I keep getting over voltage disconnects and hi voltage shutdown of the inverter.
Currently the load is 2 chest freezers and some led lights.
I could use some guidance.
Click to expand...
How are those Stion panels performing compared to spec? I am looking at getting a whole set of used ones (6yrs old) because they're relatively cheap ($50 per panel @ 140w), but i'm not seeing a whole lot of reviews of these panels. They were "highly rated" but with so few reviews, I'm seeing 1 or 2 people saying they're under-performing. So now I'm worried... How are yours doing??
 
andrewgokart said:
How are those Stion panels performing compared to spec? I am looking at getting a whole set of used ones (6yrs old) because they're relatively cheap ($50 per panel @ 140w), but i'm not seeing a whole lot of reviews of these panels. They were "highly rated" but with so few reviews, I'm seeing 1 or 2 people saying they're under-performing. So now I'm worried... How are yours doing??
Click to expand...
I have no complaints with them. I have not checked their performance that closely, but they have performed well. My thought is that for the cost they are a bargain. If they do underperform, it's nothing to add 1 or 2 more to the array.
Mine are for a "secondary" shop/ outbuilding.
 
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