UD5 Toolkit
Smoke Detector Battery Reminder – Online 6‑Month Alarm
Set a reminder to change smoke detector batteries every 6 months. Optional sound alert and visual countdown. Local browser notification, stay safe.
Tag: Battery Series & Parallel Calculator
7+ toolsRV Battery Drain Calculator – Online Estimate Off‑Grid Duration
Enter appliance loads and battery capacity to estimate how long your RV can run without recharging. Local simulation.
Battery Life Calculator - Online Device Runtime Estimator
Estimate how long a battery will last given capacity (mAh/Wh) and load current. Also computes backup time for power banks. Quick and local.
Bluetooth Battery Monitor - Online Read Device Levels
Connect to a BLE device and read its Battery Service characteristic. See the charge level in a gauge.
Screen Wake Lock Tester - Online Keep Screen On
Toggle a screen wake lock to prevent the device from dimming or sleeping. See the lock state and learn the API.
Battery Saver Dark Screen - Online Minimal Power Page
A completely black page to save battery on OLED devices. Click to go fullscreen. Simple utility.
Battery Series/Parallel Calculator - Online Voltage & Capacity
Combine multiple identical batteries in series and parallel and see the resulting voltage and total capacity. Electronics helper.