3. Field reference

Field	Type	Required	Range	Notes
`voltage`	number	Yes	0 – 1000	Volts (V)
`current`	number	Yes	-500 – 500	Amps (A). Negative = discharging, positive = charging, depending on your device's sign convention — be consistent per device.
`soc`	number	Yes	0 – 100	State of charge, percent
`power`	number	No	-100000 – 100000	Watts (W). Omit if not directly measured — it is derivable from voltage × current.
`soh`	number	No	0 – 100	State of health, percent
`temperature`	number	No	-40 – 150	Degrees Celsius
`cycleCount`	integer	No	> 0	Lifetime charge cycles, whole positive number
`timestamp`	ISO 8601 string	Yes	—	When the sample was measured on-device, not when it was sent. Use UTC.