Sample owner report
Your car this month
Sample vehicle: small petrol hatchback · compared against its own baseline
Summary
One thing is unusual for this car: the battery's resting voltage has been lower than its own normal for the past week. Everything else we monitor looks normal for this car.
"Normal for this car" means readings are within the range seen on the drives you marked as good. It isn't a guarantee that nothing is wrong.
Systems monitored
- Battery and chargingResting voltage, charging voltage while drivingUnusual for this car
- Engine warm-upTime to normal operating temperatureNormal for this car
- Fuel mixtureShort- and long-term fuel trimsNormal for this car
- Engine runningIdle speed stability, misfire countersNormal for this car
- Stored fault codesRead at each startNone stored
- Transmission temperatureNeeds more marked good drives in hot weatherNot enough data yet
Baseline: built from 6 drives you marked as good after driving. Drives are never added automatically, and plugging in the Link doesn't count.
Unusual for this car: battery resting voltage
After the car has been parked overnight, the battery is sitting at a lower voltage than it usually does.
What this could mean
- Something may be drawing power while the car is parked.
- The battery may not be getting fully recharged, for example after a run of short trips.
- The battery may be ageing and holding less charge.
What it doesn't mean
- It doesn't mean the battery has failed or that the car won't start.
- The charging system looks normal for this car while driving, so the alternator isn't the obvious suspect.
- We can't tell from voltage alone which of the causes above it is.
Suggested next step
If you've mostly done short trips lately, take a drive of 30 minutes or more and we'll compare the next few mornings. If it stays low, ask a workshop to check for a parked-car power draw and test the battery. You can share this report with them.
Ask about your car
Is my battery getting weaker?
I can't measure the battery's health directly, but I can tell you what I've seen. For the last 7 mornings, its resting voltage has been 12.28–12.36 V. On the drives you marked as good, it was 12.55–12.68 V. So it's sitting lower than normal for this car.
While you're driving, the charging voltage is 14.1–14.3 V, which is normal for this car. That points away from the charging system and towards either something using power while the car is parked, not enough recharging, or an ageing battery.
I can't tell which of those it is from voltage alone. A longer drive would help me rule out undercharging. If it's still low after that, a workshop can measure the parked-car draw and load-test the battery.
Is it safe to keep driving?
I can't say whether the car is safe. That needs a person to look at it. What I can say is that nothing else I monitor is unusual for this car, and no fault codes are stored. The main risk from low resting voltage is a slow or failed start, so it's worth getting it checked soon.
Workshop repair report
The owner shared the report above with a workshop. The technician who claimed the job recorded the following.
Before (measured)
- Resting voltage after overnight park: 12.31 V
- Parked-car current draw after the car's modules went to sleep: 190 mA (clamp meter)
- Battery load test: within the battery's rating
Repair
- Found an aftermarket dash camera wired to a permanent power feed, staying on while parked.
- Rewired it to an ignition-switched circuit.
- Battery kept; the load test didn't show a problem with it.
After (measured)
- Parked-car current draw after sleep: 30 mA (clamp meter)
- Resting voltage over the next 5 mornings: 12.58–12.64 V, back within this car's normal range
Why: the fault was measured Before (high parked-car draw, low resting voltage), a specific repair was recorded, and the same measurements After show the draw reduced and resting voltage back within this car's own normal range. All three are needed. Without any one of them, this report would say "More evidence needed".
This records what was measured. It isn't a guarantee that the problem won't return, and the After mornings weren't added to the baseline automatically. You can mark later drives as good if you're happy with them.
This is an illustrative sample. Pneumaion is in early development; the Link and assistant aren't generally available yet.