Why do whrtg and whavail show values that seem ten times too large?

Both registers are raw integers and must be multiplied by 10 raised to the power of the wh_sf register. If wh_sf reads as a negative number such as -1, divide the raw value by 10. Always read wh_sf first and apply it before presenting watt-hour values in any dashboard formula.

Why does soc read 0 or 65535 even though the battery is charged?

A value of 0xFFFF (65535) is the SunSpec Not Implemented sentinel, meaning the device did not populate this register. Confirm the battery firmware supports Model 713 with the soc point enabled. On some devices, SoC is only reported in the vendor-specific model and the 713 block is partially populated.

The Gateway connects but no register values update after the first read.

SunSpec devices use a dynamic register map: Model 713 does not sit at a fixed absolute address. If you configured a static base offset that does not match the actual model position in the device's SunSpec chain, reads will return errors or stale data. Use the ModbusCloud Gateway SunSpec auto-discovery or manually scan from the SunS marker to find Model 713's true start address before committing to a fixed offset.

The sta register returns an unexpected numeric code. What does it mean?

The sta register is an enumeration whose numeric values are defined in the SunSpec DER Information Model specification. Common values include charging, discharging, standby, and fault states. If an undocumented value appears, check the device manufacturer's Modbus supplement for vendor-specific extensions to the standard enumeration, as some implementations add proprietary states above the reserved range.

Free Modbus template: SunSpec Model 713 — DER Storage Capacity

Name: SunSpec Model 713 — DER Storage Capacity
Brand: SunSpec
SKU: 30949cbb-f294-416a-bdca-79e59e71d605

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Free Modbus template: SunSpec Model 713 — DER Storage Capacity | ModbusCloud

Registers (9)

9 read / 0 write

Name	Address	Function	Type	Unit	Access
id SunSpec model identifier, fixed value 713 for DER Storage Capacity.	0	FC03	uint16		R
l Model length in registers, excluding the id and l registers.	1	FC03	uint16		R
whrtg Nameplate energy capacity of the storage device, watt-hours.	2	FC03	uint16	WH	R
whavail Available stored energy, watt-hours, usable at current state of charge.	3	FC03	uint16	WH	R
soc State of charge as a percentage of actual usable capacity.	4	FC03	uint16	Pct	R
soh State of health as a percentage of nameplate capacity.	5	FC03	uint16	Pct	R
sta Operational status enumeration: charging, discharging, standby, or fault.	6	FC03	uint16		R
wh_sf Scale factor (power of ten) applied to watt-hour registers whrtg and whavail.	7	FC03	int16		R
pct_sf Scale factor (power of ten) applied to percentage registers soc and soh.	8	FC03	int16		R