Resource / Battery-Life Model

How should five-year tracker-card battery life be calculated?

Battery life is not nominal capacity divided by one sleep-current figure. Protocol states, advertising, connections, buzzer use, usable capacity, and design margin belong in one model.

Yuli standard tracker cards are designed around a five-year-plus target. The early estimate divides usable battery capacity by daily consumption from protocol-cycle average current, buzzer use, and other interactions. The production specification is confirmed with the target battery, firmware, card body, and operating environment.
Low-power tracker-card PCBA transitioning into a cold-pressed finished card

Method

Calculate daily consumption before quoting years.

Protocol-cycle average current covers wake, advertising, and sleep in normal operation. Buzzer, button interaction, connections, and updates are additional loads and should be converted to a daily average. Battery capacity also needs margin for temperature, aging, self-discharge, and cutoff voltage.

Base formulaEstimated life = usable capacity / daily consumptionUse consistent units, then calibrate the result against prototype and accelerated tests.

State Breakdown

Which data belongs in the model?

The table uses state samples from solution documentation to explain the method. Ecosystem, silicon, and firmware changes affect the figures, so the target product is tested on its own hardware and firmware revision.

191 μA

Pairing advertising sample

A high-frequency phase at 30 ms intervals for up to ten minutes, weighted by actual duration.

8.7 μA

Connected-state sample

Connection interval, payload, and duration change consumption in this state.

6 μA

Nearby / Separated

Advertising interval and protocol behavior define long-term weighting and require target-firmware testing.

6.85 μA

Rotating Key

The sample uses a 15-minute cycle; final behavior depends on ecosystem requirements and implementation.

Interactive Estimator

Enter project assumptions to estimate the life range.

The defaults demonstrate a standard card model. Results update when battery capacity, average current, usable capacity, or buzzer time changes.

The estimate excludes OTA, abnormal reconnection, extreme temperature, and battery-lot variation. Add state weighting, discharge curves, and prototype measurements during development.
Model estimate5.8years0.152 mAh / day

Specification Validation

How should a production battery-life specification be validated?

The model compares battery and power options and establishes design margin. A product specification records the battery model, firmware version, advertising conditions, buzzer assumptions, temperature range, and test method, supported by validation in the target card body.

Battery conditions

Confirm capacity, discharge curve, internal resistance, cutoff voltage, temperature, and aged usable ratio.

Firmware conditions

Record state weighting, advertising, reconnects, key rotation, buzzer use, and updates.

Finished-device conditions

Retest power, RF, SPL, and temperature in the final cold-pressed body to establish finished-product data.

Build a project model with the target battery and firmware.

Share the target ecosystem, product dimensions, battery model, advertising strategy, buzzer use, and operating environment. Yuli will build the battery-life model and confirm it through cold-pressed prototypes.