If you already have EV chargers installed but they’re unreliable where connectivity is poor — or you can’t bill on them cleanly — you don’t have to tear them out. An OCPP retrofit adds a small gateway that brings existing chargers onto a modern, offline-first platform, keeping the hardware you’ve already paid for.
What “OCPP retrofit” means
Most installed chargers speak OCPP (Open Charge Point Protocol), the vendor-neutral standard for talking to a backend. An OCPP retrofit puts a gateway between the charger and the network that intercepts and upgrades that communication — adding local authorisation, offline operation, and accurate billing — without replacing the wallbox.
Why not just replace the chargers?
Replacing working hardware is sunk cost: you write off the chargers, pay for new ones, and pay to install them again. At a multi-charger site that’s a large, avoidable expense — one of the cost traps covered in how to cut EV charging infrastructure costs. Retrofitting keeps the install and upgrades the intelligence.
How a retrofit gateway works
The OCPP retrofit gateway sits with the existing charger and:
- Authorises sessions locally over Bluetooth, so a driver can start charging with no round-trip to a server.
- Meters and stores each session locally, then syncs to the cloud for billing and reporting when a connection is available (store-and-forward).
- Presents one management layer across mixed hardware, so a fleet of different chargers behaves like one network.
This is the same offline-first architecture as HeyCharge’s native hardware — see how SecureCharge works.
What you gain
- Reliability where the signal is weak — underground garages included.
- Accurate, calibration-compliant billing on chargers that couldn’t do it before.
- One platform across brands, instead of a separate app per manufacturer (the backend role a CPMS plays).
When retrofit makes sense — and when it doesn’t
- Retrofit when the existing chargers are sound but limited by connectivity or billing.
- Replace when the hardware is end-of-life, not OCPP-capable, or under-powered for the site’s needs.
FAQ
Does retrofit work with any charger? It works with OCPP-capable chargers. Non-OCPP or end-of-life hardware is usually better replaced.
Do I lose anything by retrofitting instead of replacing? No — you gain offline reliability and billing while keeping the install you’ve already paid for.
Can one platform manage chargers from different brands after retrofit? Yes; that interoperability is the whole point of OCPP.
Related guides
- EV charging without internet: a complete guide
- EV charging for apartment & multi-tenant buildings
- What is a charge point management system (CPMS)?
Got existing chargers? See the OCPP retrofit gateway or talk to our team.