Why does a charging session sometimes not start?
Same charger, a different day. The driver taps the card, and the display shows an error instead of Charging. The app had listed the charger as available.
With what you know from the first stops, you can trace where the session stopped.
The questionWhere in the chain did this session stop, and how does an operator find out?
Guess firstWhat is more often behind a charger that does not start: a hardware defect or something digital?RevealHide
Often something digital: a weak mobile connection, a software state, a backend setting or a declined card. These causes can frequently be resolved remotely, without a technician on site. Hardware faults happen as well, and they need a visit.
Car and charger have to complete the handshake. After a software update on either side, individual vehicle models can need an adjustment before this works again.
For the driver, each of these looks the same: the charger does not start.
How an operator investigates
A control room sees more than the driver, and checks in a fixed order:
- Online? If not, the cause is likely the connection, and the hardware may be fine.
- Errors in the logs? Software or configuration, often fixable remotely.
- Authorisation declined? A connection or the card itself.
- Handshake stopped? Then the cause may lie with the vehicle.
A technician goes out when the remote checks do not solve it. A remote fix takes minutes, a site visit often most of a day, which is why remote diagnosis is central to running a network.
Uptime and session success
measures whether a charge point was technically able to charge. Session success measures whether individual sessions started and finished. Both matter, and operators track them separately, because a charger can be available while a particular vehicle model has trouble starting a session.
Since April 2025, operators in the EU have to publish the operational status and availability of their public chargers through an open interface, which apps and maps can use.
Check your understanding
4 questions. Answer all of them to complete this stop. Each answer explains itself.
A charger does not start, but the backend shows it online and in order. What is the best next hypothesis?
Online and in order narrows the chain: the vehicle side and the authorisation remain.
Why is remote diagnosis so important for operators?
Many charge points, one control room: the share of remote fixes is a key operating figure.
A charger reports 98% uptime. What does that figure measure?
Uptime and session success are separate figures. Operators watch both.
Which cause shows up at the charger, although the charger cannot fix it?
Some causes start in the vehicle. Session-level diagnostics help to tell them apart.
- Roaming Charging in another company's network with your own card or app. Stop 03 Glossary
- Uptime The share of time a charger was technically able to charge. Glossary
- Open Charge Alliance: Open Charge Point Protocol (OCPP). https://openchargealliance.org/protocols/open-charge-point-protocol/. Checked 07 Oct 2026.
- EUR-Lex: Regulation (EU) 2023/1804 (AFIR), Article 20: static and dynamic data, including operational status and availability. https://eur-lex.europa.eu/eli/reg/2023/1804/oj. Checked 07 Oct 2026. © European Union, reused under Commission Decision 2011/833/EU.