BMS_TemHigh on a SolaX Power battery: High temperature of BMS. Solution: Let BMS cool down to normal temperature and restart; contact after-sales
Short answer
On a SolaX Power battery, BMS_TemHigh means: High temperature of BMS. Solution: Let BMS cool down to normal temperature and restart; contact after-sales. The battery stops until the fault clears or is reset. The wording differs by model range — each is shown below.
Reviewed 24 September 2026 · 2 sources
What it means
On the Triple Power T Bat Hv S
The manual says: High temperature of BMS. Solution: Let BMS cool down to normal temperature and restart; contact after-sales.
Part involved: T-BAT SYS-HV BMS.
On the SolaX X1-Hybrid G3
The manual says: Battery Fault - over-temperature fault.
Part involved: Battery BMS internal protection/fault.
Likely causes:
- As described in manual.
Is it safe?
On the Triple Power T Bat Hv S
| Does the battery stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
The battery stops until the fault clears or is reset.
Resetting itself: after temperature normalises and restart.
Manual reset: Restart BMS (installer-guided).
On the SolaX X1-Hybrid G3
Switch the battery off at its isolator if the code comes back.
| Does the battery stop? | Partly |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The battery keeps running with some functions stopped.
Resetting itself: protection states may clear when conditions normalise; hardware faults do not.
Manual reset: installer/manufacturer.
What you can check
On the Triple Power T Bat Hv S
- Read and note the exact code or light pattern and the time (photo or app screenshot).
- Look (without opening anything) that nothing is blocking the unit's vents, it is not in direct sun and the space around it is not unusually hot or cold.
- Wait for the battery to return to normal temperature - it can then restart.
- Check the battery/inverter AC isolator and the consumer-unit breaker are ON. Do not keep resetting a breaker that trips again straight away.
- Never open the battery, inverter or gateway casing and never touch DC cables, connectors or battery terminals.
- If the code stays or keeps coming back, contact your installer (quote the code) - do not keep power-cycling.
On the SolaX X1-Hybrid G3
- Read and note the exact code and time from the inverter display or app (screenshot).
- Do not open the battery. If it is hot, swollen, smoking or smells, keep away, switch off at the AC isolator if safe and call the installer (and 999 if fire).
- Where the SolaX manual says 'press the ESC key to restart the inverter', a homeowner can do that on the display. Steps that say 'disconnect PV+/PV-/battery' are for the installer only.
What the engineer will check
On the Triple Power T Bat Hv S
- Restart BMS via POWER button/switch sequence; check BMS-inverter CAN cable and series box; check module firmware/type match; contact SolaX after-sales.
Who to ask for: battery storage installer.
Certification: SolaX-trained installer ('skilled worker' per manual); MCS battery certification.
On the SolaX X1-Hybrid G3
- Read BMS logs.
- Check cell voltages/temperatures.
- Update BMS firmware if the manual says so.
- Arrange RMA via installer.
Who to ask for: Battery installer.
Certification: Electrician competent in electrical energy storage (BS 7671 Chapter 57; IET Code of Practice for Electrical Energy Storage Systems), ideally the MCS battery installer (MIS 3012); brand-approved installer to keep warranty.
What you might notice
Sources
- T-BAT-SYS-HV-S25 / T-BAT-SYS-HV-S36 User Manual, Version 16.0 ↗ · 16.0 · page 47-49 · Reviewed 24 September 2026
- X1-Hybrid G3 User Manual (EN) ↗ · page PDF p.34-35 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026