A charger that is out of service brings no income, and drivers remember the site that let them down. Keeping public chargers working is steady, practical work: the right checks, the right spares nearby, and records that satisfy the inspector.
Why public chargers go out of service
The parts that wear are the ones people handle: connectors, cables and holsters. After those come power modules and fans in DC chargers, communication faults, and payment terminals. Most failures are routine to prevent and quick to fix with the right spares nearby.
- Connectors and cables get dropped, driven over, left on the ground and pulled at an angle. Worn pins and loose contacts run hot, and heat leaves burn marks well before it causes a failure.
- Power modules and fans in DC chargers work hard in heat and dust. Clogged filters raise temperatures, and hot modules cut their output or trip.
- Communication drops when a SIM, router or network link fails. A charger that cannot reach its management software may refuse sessions or fail to take payment.
- Payment terminals and screens face sun, rain and heavy use.
Near the coast, salt air and monsoon rain add corrosion and moisture to the list, so enclosure seals and drainage deserve extra attention.
What the rules ask of owners
The Central Electricity Authority's (CEA) Safety Regulations 2023 make the owner of a charging station responsible for having the maker's specified residual current device (RCD) and station tests carried out, and for keeping design, test and inspection records for at least seven years. Earth-continuity monitoring, lightning protection and fire-retardant, halogen-free enclosures are required at every station. Chapter XI (regulations 123–128) also sets rules for the site itself:
No adaptors or extension leads; socket outlets at least 800 mm high; the vehicle within 5 m of the charging point.
An operations and maintenance (O&M) contract can carry out the tests and keep the records, but the duty stays with the owner. Choose a provider whose records you could hand to an inspector as they are.
What good O&M looks like
Remote monitoring. Chargers that speak the Open Charge Point Protocol (OCPP) report to their management software: heartbeats that show they are online, error codes, and the status of each connector. Many faults clear remotely, with a reset or by releasing a stuck connector, and firmware updates go out under change control.
OCPP 2.1 was published as IEC 63584-210:2025; OCPP 2.0.1 was approved as IEC 63584 in 2024.
A preventive schedule. Site visits on a fixed calendar cover:
- Connector and cable inspection, including pin wear and burn marks
- Thermal scans of panels and terminations
- Filters and fans in DC power modules
- Torque checks
- RCD trip and earth-continuity tests to the maker's instructions
- Surge-protection status
- Enclosure seals, signage and lighting
- Payment terminal and network checks
A local spares pool. Connector and cable assemblies, power modules, contactors and surge protectors, and control and communication boards, held near the site. Spares decide how long a known fault stays unfixed.
Records kept for inspection. Every visit, test result and repair is logged against the charger and kept for at least seven years.
How to measure it
Upkeep is measured with three terms. Agree each definition in the annual maintenance contract (AMC) before the first visit, because the same word can hide very different formulas.
| Term | What it measures |
|---|---|
| Availability | Time a charger can start a session ÷ scheduled time, excluding agreed exclusions such as grid outages. |
| Session success rate | Sessions that start and deliver energy ÷ sessions attempted. |
| Mean time to repair (MTTR) | Average time from a fault being reported to the charger working again. |
The exclusions deserve the closest reading. A grid outage or vandalism may reasonably be excluded; a missing spare should not be. We define these terms in every AMC and report them monthly. We don't publish availability percentages; targets are agreed site by site.
Older chargers
Bharat AC-001 and DC-001 chargers are no longer in the national standards annex, and some early sites lack OCPP. A health check tells you whether to repair, migrate or replace.
Chargers are type-tested by NABL labs to the Annex I standards, and use open protocols.
A health check looks at the charger's condition, whether parts and firmware support are still available, whether it can connect to current management software, and whether its connectors suit the vehicles that now use the site. Sometimes a repair and a communications upgrade are enough; sometimes replacement costs less over the next few years.
What to ask an O&M provider
- Response and repair near your site. Who comes, from where, and how response and repair times are written into the AMC.
- Spares. Which spares they hold for your charger models, and where.
- Availability. How they define and measure it, which exclusions they apply, and which data the report draws on.
- Software. Whether they can work with your charging software over OCPP, or run it for you, and who holds the data.
- Records. How test and inspection records are kept, and whether you could hand them to an inspector for the full seven years.
We look after chargers as part of operations and maintenance, including chargers someone else installed, and can cover a battery and solar at the same site under one contract. See how upkeep fits into our EV charging work.