Battery forecaster
How long will
your phone last?
Aster uses your phone’s GPS for hours. Set your starting battery, pick a mode, and see exactly how long tracking lasts — all four modes, with or without auto-fallback.
Scenario
Tracking lasts with auto-fallback
9h 59m
If you stayed only in this mode
Actually spends 4h 40m here during the cascade (70% of battery).
Actually spends 1h 46m here during the cascade (15% of battery).
Actually spends 1h 33m here during the cascade (7% of battery).
Actually spends 2h here during the cascade (8% of battery).
Estimates from in-app burn rates. Real consumption varies with signal strength, temperature, and other apps. Cell signal is the single biggest variable — weak signal can double the drain.
How the ladder works
Four modes. One ladder. No fiddling.
Aster has four battery modes, each with a different GPS sample rate and upload cadence. The default — Live — gives spectators the smoothest tracking at the cost of the fastest battery drain. The other three tiers progressively slow GPS sampling to extend tracking life.
You pick a starting mode when you tap Start. Most riders leave it on Live — that’s the right call for races up to ~2 hours. For longer rides, the app’s auto-fallback takes over: at 30% battery it drops you one tier (Live → Standard), at 15% another (Standard → Endurance), at 8% the final step to Ultra. A small banner pops up each time so you know.
You can also turn auto-fallback off and stay locked to your chosen mode for the whole ride — useful if you’ve picked Endurance from the start and don’t want any surprises. The calculator above lets you model both: pick a scenario pill to see “Auto” (the cascade) or “Live/Standard/Endurance/Ultra” (locked) durations.
Other ways to stretch your battery
Low-effort wins.
- Lock the screenwhen you’re not checking it — the display is the single biggest battery drain after GPS.
- Drop screen brightness if you do leave it on.
- Close other apps before the start — Spotify, Strava, navigation apps all compound the drain.
- Keep the phone out of direct sun if possible — heat reduces battery efficiency significantly.
- Bring a battery pack for multi-hour rides. A 5,000 mAh pack weighs almost nothing and is cheap insurance.
- Charge while you ride if your phone is bar-mounted near a power bank — some riders swear by it for ultra-distance days.
- Don’t use airplane mode. Aster needs a data connection to upload positions — airplane mode means your spectators see a frozen position the whole time.