Wearable battery-life estimator
t ≈ (capacity × derating) / average current. Radio peaks, temperature and cutoff voltage are not modelled.
21.3 h
0.89 days at that average draw.
How to use the wearable battery-life estimator
Enter capacity, measured or budgeted average current, and a derating factor, then compare hours to your wear prescription. Check study coverage with the wear-time / data coverage calculator, sketch packaging aging with the shelf-life Q10 estimator, or shortlist process constraints with the sterilization modality picker.
Sizing power budgets for a wearable or implant peripheral?
Average-current math omits radio peaks and temperature. Book a Consultation with our clinical engineering team to turn duty cycles, cutoff voltage and wear-time targets into a verification plan.
Book a ConsultationFAQ
- How does this battery-life estimator work?
- It uses t ≈ (capacity_mAh × derating) / average_current_mA, then reports hours and days. Derating (0–1) is a simple allowance for incomplete discharge, aging and margin. Radio peaks, temperature, cutoff voltage and Peukert effects are not modelled.
- Why include a derating factor?
- Nameplate mAh is rarely fully available at the wearable’s cutoff voltage, temperature and end-of-life. A derating such as 0.8 is a planning heuristic, not a substitute for cell datasheets and measured average current.
- How should I estimate average current?
- Build a duty-cycle budget: sleep, sense, compute, radio TX/RX and UI currents weighted by time fractions, then measure on representative hardware. Using only the datasheet sleep current will overstate life.
- How does battery life connect to wear-time coverage?
- If the battery dies before the prescribed wear window, coverage falls and endpoints suffer. Pair this estimator with the wear-time / data coverage calculator when setting study wear prescriptions.
- Does sterilization or shelf life change the estimate?
- Yes for some chemistries and packaging. Radiation dose, EtO residuals, heat and long shelf storage can change internal resistance and available capacity. Re-measure after the process you will actually ship.
- Is this suitable for implantable primary cells?
- Only as a first educational sketch. Implantable power budgets need hermetic packaging, longevity models, and clinician-facing end-of-life indicators far beyond this form.
Educational only. Not medical advice, not a regulatory determination, and not a substitute for qualified RA/QA, legal, clinical, or statistical counsel. Wearable battery-life estimator does not submit to FDA, Notified Bodies, or IRBs.
Related wearable & packaging tools
Sizing power budgets for a wearable or implant peripheral?
Average-current math omits radio peaks and temperature. Book a Consultation with our clinical engineering team to turn duty cycles, cutoff voltage and wear-time targets into a verification plan.
Book a Consultation