Native tool · INT.05 Care · runs on this page
Parked Battery Countdown
Airport trip, winter storage, the weekend car under a cover — every parked day, the electronics quietly sip. Here's how many days you actually have before a risky start.
Standby countdown · v1.0
Lead-acid / AGM starter batteries- Comfortable windowup to ~11 days
- Deeply discharged by~32 days
- Longer than that?maintainer or disconnect
Risky start = ~40% of usable capacity consumed. Deep discharges also permanently age lead-acid batteries.
Where the days go
A parked modern car is never off. The alarm, keyless receiver and dozens of sleeping modules draw a constant 30–85 mA. That sounds like nothing until you multiply by 24 hours: a 50 mA drain removes 1.2 Ah every single day, from a battery that might hold 48 usable amp-hours when healthy — and only 60% of its label rating after a few winters.
The countdown ends well before "flat". Starters demand huge current, and a lead-acid battery below roughly 60% charge on a cold morning is a coin flip. Worse, every deep discharge sulfates the plates and permanently shortens battery life, which is why the tool's honest advice past three weeks is a maintenance charger or a disconnected negative terminal, not optimism.
Standby drain reference
| Setup | Typical drain | Ah lost / week |
|---|---|---|
| Older car, no alarm | ~20–25 mA | ~3.5–4 |
| Modern car, factory alarm + keyless | ~30–50 mA | ~5–8.5 |
| + GPS tracker or dashcam standby | ~70–100 mA | ~12–17 |
| Something is wrong (light stuck on) | 250+ mA | flat in days |
FAQ
Usually two to four weeks with a healthy battery. Modern cars draw 30–85 mA continuously; aging batteries shorten that considerably, and freezing weather cuts effective capacity by about a quarter.
Parasitic draw: the alarm, keyless receiver, clock and dozens of sleeping modules. A healthy modern car draws roughly 30–50 mA; trackers, dashcams in parking mode or a fault can multiply that.
Connect a maintenance charger, or disconnect the negative terminal — a healthy battery then self-discharges only a few percent per month. Fully charge before parking either way, and keep keyless fobs away from the car.