HESP series hybrid inverters (single-phase 4-12 kW and three-phase 8-12 kW)
SRNE 03 error code
Battery not connected (BatOpen): the inverter cannot see a battery on the DC side and stops the output.
Likely causes
- Battery breaker or DC switch open
- Blown battery fuse or tripped DC breaker
- Loose or corroded battery terminal
- BMS in discharge protection with its contactor open
- Battery type/protocol setting that stops discharge
Checks to run, in order
- 1Measure DC voltage at the inverter battery terminals
- 2Check the battery breaker, fuse and DC isolator
- 3Read BMS status and LED indications on the battery
- 4Verify the selected battery type and BMS protocol
Fixes
- Close the breaker and replace a blown fuse
- Re-terminate loose battery cables to the specified torque
- Wake the BMS or clear its discharge protection, then restart the inverter
- Set the correct battery type and lithium protocol
When to escalate
If correct battery voltage is present at the terminals and the alarm stays, the internal DC detection circuit needs distributor service.
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 SRNE 03 mean?
Battery not connected (BatOpen): the inverter cannot see a battery on the DC side and stops the output.
How do I fix SRNE 03?
Close the breaker and replace a blown fuse Re-terminate loose battery cables to the specified torque Wake the BMS or clear its discharge protection, then restart the inverter Set the correct battery type and lithium protocol
When should I escalate SRNE 03?
If correct battery voltage is present at the terminals and the alarm stays, the internal DC detection circuit needs distributor service.
Can I reset SRNE 03 myself?
Only after isolating the AC and DC sides and running the checks above. If SRNE 03 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show SRNE 03?
SRNE 03 is documented for HESP series hybrid inverters (single-phase 4-12 kW and three-phase 8-12 kW). Confirm the code on your own unit's display or manual before ordering parts.
More SRNE error codes
- SRNE 01Battery undervoltage alarm: the battery voltage has fallen below the [Batt. Under volt. alarm] value under Battery Setup, and the alarm does not by itself stop the output.
- SRNE 02Battery discharge average current overcurrent, detected by software (BatOverCurrSw); the inverter limits or stops discharge.
- SRNE 04Battery undervoltage stop-discharge (BatLowEod): the battery has reached the low-voltage cut-off and the inverter has stopped discharging.
- SRNE 05Battery overcurrent detected by hardware protection (BatOverCurrHw); the inverter shuts the output down.
- SRNE 06Charging overvoltage protection (BatOverVolt): battery voltage rose above the over-voltage cut-off and charging was stopped.
- SRNE 07Internal DC bus overvoltage detected by hardware protection (BusOverVoltHw); the inverter stops the output.
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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