Smart Lock Energy Usage Calculator

Get the numbers that matter: **daily Wh**, **battery autonomy (days)**, and **minimum solar panel size** for your smart lock. Works for 12 V systems and 5 V USB-powered locks.

Tip: Most locks idle around 0.2–0.5 W. That’s just 4.8–12 Wh/day — a tiny panel (5–10 W) can cover this easily with a small battery buffer.

Inputs

Standby Draw (W)

Actuation Power (W)

Actuation Time (sec/day)

System Voltage (V)

Converter Efficiency (%)

Battery Capacity (Wh)

Usable DoD (%)

Peak Sun Hours (h/day)

Panel Derate (%)

Presets help sanity-check: low ≈ 0.2 W standby; high ≈ 0.5 W standby + more use.

Results

— daily energy use (Wh/day)

— days of autonomy from battery

— minimum panel size (W) to break even

— daily current draw (Ah/day) @ system voltage

— usable battery capacity (Ah)

—

Enter values and hit Calculate.

Assumptions: standby runs 24/7; actuation energy adds linearly; converter efficiency accounts for 12→5 V or similar buck loss; panel derate includes angle, temperature, wiring, and controller efficiency.

Next steps: Pair this with Off-Grid design or RV wiring. Keep total parasitic loads small to extend boondocking days.