What you will see
- Warning 20 or 33 with a lithium battery
- Battery percentage missing
- Warnings 34–45 with beeping
Why it happens
The SPF talks to lithium batteries over CAN or RS485. A wrong cable, wrong protocol setting or a battery that is off breaks the link.
Battery warnings mean the BMS is protecting its cells.
Diagram
Lithium link and battery warnings
Link lost
Warning 20 or 33: check cable, protocol, battery on.
Battery protecting itself
Warnings 34–45: cell voltage, current or temperature.
What you can check yourself
- Check the battery is on
- Note whether it started after a battery change
- Keep the battery space cool and ventilated for temperature warnings
What not to do
- Do not change protocol settings yourself
- Do not open the battery
When to call us
- Check the communication cable and port
- Set the correct BMS protocol
- Read battery data for warnings 34–45
Lithium upgrades
We connect and configure lithium batteries with Growatt SPF inverters in Faisalabad, Lahore and nearby towns.
Send us
the warning code and battery brand and model