Battery monitoring that works when you're not there
A €30 Bluetooth monitor shows voltage when you stand next to the car. QZ reports over 4G wherever the car parks — and warns you while there is still time to act.
Where a Bluetooth monitor stops
For the money, a Bluetooth monitor is a decent tool: at the car, it shows you the voltage. Its limit is structural — roughly 10 metres of range. Readings, and any alert the model offers, reach you only while your phone is near the car. Batteries tend to die exactly when you're away.
- Range of about 10 m — a car in an underground garage or another city is simply out of reach.
- Alerts, where a model has them at all, arrive only while your phone is in range — that is, near the car.
- A car in winter storage or parked at the airport goes unwatched for weeks.
- A maintenance charger keeps the battery full, but it needs a socket — and tells you nothing remotely.
How QZ works
A real case: the founder's car
The founder's Maserati: QZ flagged the weakening battery days ahead as the voltage slid to 11.94 V. The owner replaced it calmly, before being stranded. That is one real story, not a guarantee — but when a battery weakens gradually, QZ can warn days in advance — as in this case.
Common questions
Why pay €199 when a Bluetooth monitor costs €30?
If the car sleeps in your own garage and you check it weekly, the €30 device is fine — we say that plainly. QZ is for what that device structurally cannot do: watching the battery when you are not there. 4G reporting, the SIM and the first year of service are included from €199.
If your car sits next to a power socket, a quality maintenance charger is a legitimate choice — on our own test bench we use the CTEK MXS 5.0. We have no ties to the manufacturer; we recommend what we use ourselves. And with QZ installed, it can confirm the charger is actually charging.
I'm not comfortable installing electronics in my car.
It's two leads at the battery — the same operation as connecting a charger. No cut wires, no CAN bus, no OBD. About 10 minutes.
My garage is underground — will there be signal?
QZ needs only ordinary mobile signal, not Wi-Fi or Bluetooth. If your phone gets any signal in the garage — even weak — the device connects. Underground garages are exactly where a Bluetooth link with roughly 10 m of range cannot help at all.
Will it void my car's warranty?
QZ connects only at the battery — it never touches the CAN bus, the OBD port or the vehicle wiring. From the car's point of view, it is the same connection as a maintenance charger. Warranty terms can still differ by manufacturer and vehicle; ask your dealer if in doubt.
199 € incl. VAT — device, SIM, data and the first 12 months of service. Shipping 5 € (for now we deliver to Slovakia only). Then 49 €/year, renews automatically, cancel any time.