LVTS-5220-HVX high-voltage battery - BMS alarm page on the battery touchscreen (LVTOPSUN BMS protection alarms)
LVTopsun Chg Cell Ud_V error code
A cell fell below the BMS charge under-voltage limit while the pack was being charged.
Likely causes
- Weak or failing cell in the pack
- Large cell imbalance
- Voltage-sense harness or module connector fault
- Charge current too high for the pack temperature
Checks to run, in order
- 1Read every cell voltage on the battery touchscreen
- 2Compare the low cell with the rest of the pack and the other modules
- 3Inspect the sense harness and module connectors
- 4Check the charge current against the battery datasheet limit
Fixes
- Reduce the charge current and retry
- Run a balance cycle and recheck the cell
- Replace the module if the cell remains low after balancing
When to escalate
If the cell stays below the limit with a reduced charge current, stop using the pack and ask the distributor to bench-test the module.
Fix it with the right tools
Check the system around the fault before replacing parts: load, battery bank, PV string and commissioning settings. If you need a second opinion, send the code and your inverter model to our team.
Before you open the inverter
- Isolate both the AC and DC sides, then confirm the display is dead before touching terminals.
- Use insulated tools and one hand where possible. DC arcs do not self-extinguish like AC.
- If you see burnt terminals, swollen cells, leaking electrolyte or a burning smell, stop and escalate instead of resetting the fault.
Questions installers ask
What does LVTopsun Chg Cell Ud_V mean?
A cell fell below the BMS charge under-voltage limit while the pack was being charged.
How do I fix LVTopsun Chg Cell Ud_V?
Reduce the charge current and retry Run a balance cycle and recheck the cell Replace the module if the cell remains low after balancing
When should I escalate LVTopsun Chg Cell Ud_V?
If the cell stays below the limit with a reduced charge current, stop using the pack and ask the distributor to bench-test the module.
Can I reset LVTopsun Chg Cell Ud_V myself?
Only after isolating the AC and DC sides and running the checks above. If LVTopsun Chg Cell Ud_V returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show LVTopsun Chg Cell Ud_V?
LVTopsun Chg Cell Ud_V is documented for LVTS-5220-HVX high-voltage battery - BMS alarm page on the battery touchscreen (LVTOPSUN BMS protection alarms). Confirm the code on your own unit's display or manual before ordering parts.
More LVTopsun error codes
- LVTopsun Ahesion FltThe BMS detected a main contactor or relay that has stuck closed (contact adhesion).
- LVTopsun Chg Bat Ov_VThe pack voltage rose above the BMS charge over-voltage limit.
- LVTopsun Chg Bat Ud_VPack voltage stayed below the BMS charge under-voltage limit while the pack was supposed to be charging.
- LVTopsun Chg Cell Ov_VCharging was stopped because a cell reached the BMS charge over-voltage limit.
- LVTopsun Chg Diff_TThe temperature difference between BMS sensors exceeded the limit during charge.
- LVTopsun Chg Diff_VThe voltage difference between the highest and lowest cell exceeded the BMS limit during charge.
Guidance reviewed 17 October 2026 by the Mishka Energy installer team. Error codes vary by brand, model family and firmware; confirm against the manufacturer manual.
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