LVTS-5220-HVX high-voltage battery - BMS alarm page on the battery touchscreen (LVTOPSUN BMS protection alarms)
LVTopsun Chg Bat Ud_V error code
Pack voltage stayed below the BMS charge under-voltage limit while the pack was supposed to be charging.
Likely causes
- Charger or inverter not delivering current
- CAN communication failure, so the inverter does not charge
- Charge current limit set to zero or very low
- Pack voltage sensing offset
Checks to run, in order
- 1Confirm charge current on the inverter and on the battery touchscreen
- 2Check the CAN cable and the protocol selected on the battery
- 3Check the inverter battery type and charge current limit
- 4Measure pack voltage at the terminals against the display
Fixes
- Restore CAN communication and reselect the protocol
- Raise the charge current limit within the battery datasheet
- Restart the inverter and confirm charge current flows
When to escalate
If the inverter reports charge current but the pack voltage does not rise, ask the distributor to check the BMS current measurement.
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 Bat Ud_V mean?
Pack voltage stayed below the BMS charge under-voltage limit while the pack was supposed to be charging.
How do I fix LVTopsun Chg Bat Ud_V?
Restore CAN communication and reselect the protocol Raise the charge current limit within the battery datasheet Restart the inverter and confirm charge current flows
When should I escalate LVTopsun Chg Bat Ud_V?
If the inverter reports charge current but the pack voltage does not rise, ask the distributor to check the BMS current measurement.
Can I reset LVTopsun Chg Bat Ud_V myself?
Only after isolating the AC and DC sides and running the checks above. If LVTopsun Chg Bat 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 Bat Ud_V?
LVTopsun Chg Bat 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 Cell Ov_VCharging was stopped because a cell reached the BMS charge over-voltage limit.
- LVTopsun Chg Cell Ud_VA cell fell below the BMS charge under-voltage limit while the pack was being charged.
- 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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