LG RESU10H Troubleshooting

Troubleshooting Alarm Messages Related to the LG RESU10H Battery

Note 1: If any of these alarm messages persist after troubleshooting please contact Ginlong Solis USA Service - unless instructed to contact LG Chem Support (service line phone numbers are on the last page).

Note 2: If an RMA is to be issued for the battery, please fill out the form included in this article and then contact LG Energy Solutions support using the number at the bottom of this article. 

For all of these troubleshooting steps, the inverter AC switch/breaker must be turned OFF 

  1. OV-Vbatt1
    • The inverter is detecting abnormally high voltage coming from the battery
    • The nominal DC voltage range of the battery is 350-450V
    • Measure the DC voltage at the battery input terminals with the fuses in and battery switches ON
    • Turn the battery switches OFF and then back ON after a few minutes – measure the voltage again
    • For advanced troubleshooting, contact the  Solis USA Service line
  2. OV-Vbatt-H
    • This alarm is similar to OV-Vbatt1 except that in this case there is a battery hardware fault
    • Inspect the communication wires at both ends – do a tug test to ensure they are snug
    • Turn the battery switches off and then back on after a few minutes
    • Follow the commissioning steps found on page 11
    • If the error code persists, the battery BMS is most likely experiencing difficulties 
    • Contact LG Energy Solutions Support 
  3. UN-Vbatt1
    • The inverter is detecting abnormally low voltage coming from the battery
    • With the battery DC fuses pushed in, measure the DC voltage coming from the battery
    • If the voltage is zero, make sure that both of the battery switches are turned on
    • If the voltage coming from the battery is less than 85V contact LG Chem Support
    • If the voltage is more than 85V then the battery needs to be charged
    • In California, only the PV can charge the battery – check your Time Charging Mode settings
    • Outside of California, the grid can charge the battery – check your Time Charging Mode settings
  4. NO-Battery
    • The inverter does not detect a battery connected 
    • Turn both battery switches to the OFF position – check the battery fuses in the inverter to make sure they are not blown – replace the fuses if they are – leave the fuses pulled out for now
    • Turn the battery switches ON and then check polarity at the input terminals – turn the switches back off
    • Push the battery fuses in and then turn the battery switches ON
    • Follow the commissioning steps on page 11 to configure the inverter for the LG Battery
    • Measure the DC voltage coming from the battery – if the voltage is less than 84V contact LG Energy Solutions
    • If the voltage is more than 85V and the inverter still says “NO-Battery” after performing these steps, contact Solis USA Service line
  5. LG-DDC-OV
    • This also means that the voltage coming from the LG battery is too high
    • Turn each battery switch off and leave them like this for a few minutes – turn the inverter off as well
    • Turn the inverter and battery switches back on and then go to Advanced Settings – Battery Control – Battery Select – Lg_HV then press Enter and then Enter three more times and finally Save & Send
    • Go to Information – BMS Info to check the voltage coming from the battery – the voltage should be within 350-450V but if it is higher than turn the battery off and contact LG Energy Solutions Support line
    • Give the battery a few minutes - then it should turn on and begin accepting a charge as long as the commissioning was done correctly 
    • If the error code persists, contact Solis USA Service line



Checking the LG Energy Solutions Battery

First, check the indicators on the front of the battery to determine the state of the battery pack. A warning state is triggered when a condition, such as voltage or temperature, is beyond design limitations. The battery pack’s BMS periodically reports its operating state to the inverter.

When the battery pack falls outside of established parameters, it enters a warning state. When a warning is reported, the inverter immediately stops operation and displays an alarm message. The battery’s “FAULT” light will be lit.

IMPORTANT: If the battery voltage drops below 84V it will need to be charged up with a special device. The battery will not accept a charge from the grid or PV at this point. Measure the voltage coming from the battery with the battery switches on and fuses pushed in. The battery will also need to have been commissioned in order to properly measure the voltage. See page 11.

When the battery accepts a charge or discharges energy it begins to heat up. When the battery gets too hot it will shut down, this is a safety feature designed to prevent damage. It is ideal for the battery and the inverter to be mounted in the shade, or at least not on a southern exposure unless they are covered. Take note of the physical location of the equipment as it may factor in to diagnosing the issue. 

The inverter’s alarm message OR issue with the battery will most likely be related to one of the following things: 

  1. Battery Over Voltage
    1. See “OV-Vbatt1” above
  2. Battery Under Voltage
    1. See “UN-Vbatt1” above
  3. No Battery Connected
    1. See “No-Battery” above
  4. Battery Discharge Over Current
    1. See “OV-DCA1” above
    2. The discharge current should not exceed 14.3A
  5. Battery Charge Over Current
    1. Use a DC amp meter to measure the current going to the battery
    2. The charge current should not exceed 11.9A 
  6. BMS Internal Communication
    1. This will result in the battery not communicating with the inverter
    2. Check the comm wires – if they are installed correctly then contact LG Chem Support
    3. Pages 9-10 go over how to install the comm wire between the battery and the inverter
  7. Battery Over Temperature (more than 113 F)
    1. The inverter currently does not have an alarm message for this
    2. In this case, the battery will first reduce energy discharged and then cease discharging completely until it has cooled down to operating range
  8. Battery Under Temperature (less than 14 F)
    1. The battery will not charge or discharge until the temperature increases
    2. The battery may discharge but only a portion of it is capable of being utilized 

How to Properly Turn On the Battery:

  1. Turn on the Auxiliary power ON/OFF switch after installation battery pack. Make sure that the battery switch is in the OFF position (including Trip position)
  2. Move the battery switch to the ON position
  3. Seconds after the battery switch is ON, 4 LEDs will be lit
  4. Make sure that ON indicator is on and see if the battery pack is successfully initialized. The power on indicator on the front should turn on in green
  5. Turn on the inverter

How to Properly Turn Off the Battery:

  1. Turn off the inverter
  2. Remove the wiring box cover
  3. Turn off the battery pack by moving the battery switch to the OFF position
  4. Make sure that every indicator light on the battery pack is off. It should take one minute at the most
  5. Replace the inner cover and wiring box cover



The alarm messages will clear when the system is able to resume normal operation. If the battery pack or inverter are still not working properly after troubleshooting, please contact LG Energy Solutions Support or Solis USA Service for advanced support:

  • LG Energy Solutions Support: +1(888)865-3026 (option 4)
  • Solis USA Service: +1(866)438-8408  


Please have the following information ready when you call Solis USA Service to help us provide the quickest and most effective service:

1. Inverter model and serial numbers

2. Alarm messages being displayed

3. Troubleshooting steps performed

4. DC voltage at the battery input terminals 

5. Status of the battery (lights, SOC)

Victor is the author of this solution article.

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