LG fault guides
Plain answers to the fault codes and alerts we see most often on solar systems, with what our own monitoring and service records show.
- LG RESU 10H battery recall: what it means and what to do
LG Energy Solution Michigan recalled LG Chem RESU 10H home batteries in December 2020, August 2021 and October 2022 because they can overheat and pose a risk of fire and harmful smoke. The 2020 and 2021 recalls cover batteries whose serial number begins with R15563P3 and offer a free replacement. The 2022 recall uses a remote software update that monitors the cells and shuts the battery down if a fire risk is detected.
- LG RESU battery FAULT light on: what it means and what to do
When the FAULT light on the front of an LG Chem RESU battery is on, the battery is in a warning state because a condition such as voltage or temperature is outside its design limits. LG says the inverter stops operating when a warning is reported, and the warning clears on its own if the battery returns to normal. If it does not clear, the battery needs a qualified technician.
- LG RESU battery not charging: what it means and what to do
If your LG Chem RESU battery's ON light is lit but it never shows Charging or Discharging, LG's manual points first to the inverter: firmware versions and the inverter's battery settings. On SolarEdge systems, a battery state of energy below 10% that keeps falling while solar is producing is a related symptom. SolarEdge's first step for that is a battery self-test, which your installer runs.
- LG RESU with SolarEdge Error 3x6B: what it means and what to do
On a SolarEdge inverter, "Error 3x6B" means Battery communication error: the inverter has lost communication with the battery, such as an LG Chem RESU, which LG lists as compatible with SolarEdge inverters. SolarEdge's fix is to make sure the RS485 and Enable (En) wires between battery and inverter are connected correctly and that the battery is set up correctly in the inverter.