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When EV chargers show up as offline, unavailable, or stuck in some confusing status, the hardware often gets blamed first.
But more often than not, the real issue isn’t the charger itself.
It’s the conversation between the charger and the software behind it.
That conversation happens through OCPP – and when it breaks down, chargers can look dead even when they’re standing there, powered on, doing absolutely nothing wrong.
This guide walks through OCPP troubleshooting the way operators actually experience it: step by step, without jargon overload, and without assuming everything is broken.
Ready? Let’s get started!
OCPP, or Open Charge Point Protocol, is the standard “language” that lets an EV charger talk to a charging management system (often called a CSMS or backend).
OCPP is maintained by the Open Charge Alliance and is widely used because it allows chargers and software from different vendors to work together.
When OCPP communication fails, chargers don’t necessarily stop working – but operators lose visibility and control.
Because many of the most common EV charging issues are communication problems, not hardware failures.
Understanding OCPP lets operators:
In short: fewer truck rolls, less downtime, fewer headaches.
Before diving deep, here’s the big picture:
Now let’s slow that down and do it properly.
Jumping straight into resets without context usually makes things worse.
Most sites run OCPP 1.6, though OCPP 2.0.1 is becoming more common.
(Open Charge Alliance overview: https://www.openchargealliance.org/protocols/)
Always confirm the version before troubleshooting.
This tells you where problems can hide.
Also note:
Most “mystery” OCPP issues live somewhere in this chain.
Before changing anything, gather:
Troubleshooting without this context is guesswork.
You don’t need to memorize the entire protocol. You need to understand three messages.
This is the charger saying: “Hi, I’m here. This is who I am”.
The backend replies with whether the charger is accepted and how to proceed.
If BootNotification fails, nothing else matters.
Heartbeats are simple “I’m still alive” messages sent at regular intervals.
If the backend stops receiving heartbeats, it assumes the charger is offline – even if the charger thinks it’s connected.
This tells the backend what the charger is doing:
(and others, depending on version)
If statuses don’t update correctly, operators get misleading dashboards.
In most systems, offline means:
It does not always mean the charger lost power.
Patterns matter more than symptoms.
Check the basics:
Many chargers fail quietly when one of these changes.
OCPP usually runs over WebSockets, which stay open for long periods.
This is a very common cause of “silent offline” chargers.
In backend logs, look for:
Rejections often happen due to:
Boot loops – where the charger keeps rebooting and re-registering – are also a red flag.
Incorrect system time can cause:
If available, confirm the charger’s clock or NTP settings.
In order:
Avoid random resets. Always work from evidence.
Heartbeat issues are one of the top causes of offline chargers.
The heartbeat interval defines how often the charger sends “I’m alive” messages.
If the interval is too long, networks may drop the connection first.
Common causes include:
Look for:
Logs tell a story – read them in order.
Field-tested solutions include:
Status issues confuse operators more than almost anything else.
StatusNotification reports state changes.
If the charger goes from idle to charging, the backend should know.
If something faults, the backend should know.
When this breaks, dashboards lie.
All of these point to messaging or interpretation issues.
Common root causes:
Never assume the dashboard is right without logs.
Usually due to:
This is configuration, not hardware.
Often caused by:
These loops are frustrating – but diagnosable.
Patience and clean logs help here.
Expired or mismatched certificates will break secure connections instantly.
Clock drift makes this worse.
Deep packet inspection and idle timeouts are common silent killers.
WebSockets need to stay open.
Cellular adds:
These aren’t charger problems – but they look like charger problems.
OCPP 2.0.1 expands functionality and security, but also adds complexity.
Troubleshooting depends heavily on:
Always align tooling and expectations with the deployed version.
Start with symptoms. Follow the message flow.
The best operators don’t wait for drivers to complain.
Set alerts for:
Prevention beats reaction every time.
Save ‘future you’ some pain. Always record:
Good tickets lead to fast fixes.
OCPP issues create repeat work: tickets, dispatches, parts usage, follow-ups.
Maintenance and field service platforms help by:
Tools like FieldEx help operators keep all this information in one place, so troubleshooting becomes repeatable instead of chaotic.
The value isn’t the tool – it’s the visibility.
OCPP troubleshooting isn’t magic.
It’s message flow, network reality, and clean logs – handled in the right order.
Start with connectivity.
Confirm BootNotification.
Trust Heartbeats.
Validate StatusNotification.
Do that consistently, and “offline charger” stops being a mystery and starts being a process.
Want to see FieldEx in action? Book a free demo today, or simply get in touch. We'd love to chat!
OCPP stands for Open Charge Point Protocol, a standard for charger-to-backend communication.
Because the backend isn’t receiving heartbeats or the connection dropped silently.
A small “I’m alive” message sent regularly to keep the backend aware the charger is online.
Network timeouts, firmware bugs, or rejected messages are common causes.
It’s the charger’s initial registration message to the backend.
Usually due to StatusNotification issues, firmware bugs, or backend mapping problems.
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