Symptom
Battery error reported
- ID
symptom:battery-error
- IRI
https://solarlattice.org/kb/symptom/battery-error
- Status
- active
- Also known as
- Error in the battery
The Sunny Island shows a battery error as warning W945, or as error F929 at the higher level, when the external battery management reports a fault over SiCom. For errors reported over SiCom, find and clear the cause in the external battery management system, following the battery manufacturer's documentation. Other causes of a battery error include a timeout of the battery management link, a temperature above the manufacturer's upper limit, and external battery management that was detected but never configured. A battery error can also mean the battery has worn: its current capacity (SOH) is below 70%, or its measured voltage is out of range, possibly because aging has left too little usable capacity. The error can also appear when a battery protection mode is active, or after a state-of-charge recalibration that made a large jump. Check first that the data cable to the external lithium-ion battery is connected correctly, and that the battery's ambient conditions are within the manufacturer's limits. Then check that the error message is plausible, and replace the battery if needed.
<!-- review notes
- sentence 2: support check: partial - The passage covers only F929 (error in the battery) and not all SiCom errors, though the corrective measure matches.
- sentence 6: support check: partial - Both corrective measures are stated, but they are separate fixes for different causes, and nothing says to check them first.
- sentence 7: support check: partial - Verifying plausibility and replacing the battery if necessary are stated, but the passages don't say this comes after the earlier checks or tie it to this battery error.
- sentence 4: review: partial - SOH below 70% and voltage above or below the measurement range are stated, but the passages tie aging only to the below-range case, while the sentence applies it to any out-of-range voltage and calls it all 'worn'.
- sentence 7: review: partial - Checking that the message is plausible and replacing the battery if needed are stated, but the order implied by 'Then', after the earlier checks, is not in the passages.
-->
Claims
observed_as
c1 verified · fact
Battery management error message
On Sunny Island, W945 (level 1 warning) and F929 (level 3 error) report an error in the battery that the external battery management sends over SiCom.
verified by: review-workflowverified on: 2026-10-23
c2 drafted · lead
Battery voltage range message
A battery error can be raised when the battery voltage the Sunny Island measures is above or below the permissible measurement range.
- 278742
sec=h923 h=5d8212cb9c4f
- 278742
sec=h929 h=da73424e5c91
c3 verified · fact
Battery temperature status high
A battery error can be raised when the battery goes above the upper temperature limit approved by the battery manufacturer.
- 278742
tbl=76.r8 h=47c577197df0
verified by: review-workflowverified on: 2026-10-23
Referenced by
Data