Two changes improve low-power measurements on Sonoff plugs. Firmware 2.1.3 for the Zigbee S60ZBTPF and S60ZBTPG enters Zigpy’s update collection with a fix for incorrect voltage, power and energy values below 110 watts.
Separately, ESPHome’s CSE7766-family metering driver keeps the last valid reading while a low-power load waits for its next measurement. On a tested Sonoff S60TPF, a 2.2-watt lamp previously appeared as zero in 75 of 79 reports. Keeping the measurement prevents a running small appliance from repeatedly looking switched off.
The ESPHome correction has a trade-off: after a small load actually switches off, zero can take a few seconds to appear, and up to about sixteen seconds for the smallest tested range. Higher loads keep their existing response, and the energy counter is unchanged. These are separate fixes for different hardware and software paths.