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EV charger connectivity in Ireland: why charge points go offline and what to check

A charge point that cannot reach its back office is hard to monitor or support. This guide explains how the cellular link works, why it fails, and the checks worth doing before a driver finds the fault.

How a charger reaches its back office

Commercial chargers often use OCPP, a set of messages between the charger and its management system [1][11]. OCPP is not itself responsible for downtime, but its messages and settings help operators spot it early [1]. The messages travel over the charger’s internet connection. Some chargers use Ethernet or Wi-Fi, while many commercial installations use a built-in cellular modem or a separate 4G or 5G router [11]. One charger manual offers Wi-Fi or 4G [2].

The charger sends regular pings and heartbeats so the platform can tell it is still there. A ping interval that is too long can fail to keep the mobile connection open. One that is too short costs extra data. A working ping shows the connection is up, not necessarily that the charger application is working [1].

Why chargers drop offline

The Open Charge Alliance (OCA) lists loss of the cellular data connection and a management-system outage as separate causes of downtime, alongside grid faults, physical damage and equipment faults [1]. So “offline” does not always mean “broken”. On the cellular side, check these first.

CauseWhat to check
Weak signal at the modem or antennaSimFalcon says metal boxes reduce signal and suggests an external antenna where possible [12]. Take readings at the exact position where the antenna will sit, not with a phone app (advice from an older North American specification, see below) [4].
SIM or APNSIM seated, plan active, APN correct. One manual says 4G can only work with adequate cellular signal, and that the charger may detect the APN itself or need it typed in [2].
Modem too old for the networks leftFind which radios it has. See the 3G section below.
Platform problemA management-system outage is a separate cause [1]. If every charger on one platform drops at once, suspect the platform first.

What a charger does while offline

A charger that loses its link should keep working. The OCA says running sessions continue, with their messages buffered and sent when the connection returns [1]. Starting a new session is harder. It depends on stored authorisations (an authorisation cache or a local list) and on whether the charger is set to accept unknown cards, which the OCA describes as a financial risk for the operator [1]. SEAI’s criteria for smart chargers on its home charger grant register say a charger must be configured from the factory with a fail-safe mode for when communication with an external source breaks down [9].

Single-network, multi-network or private APN

A SIM tied to one network can only use that network. SimFalcon says a multi-network SIM can register on more than one supported network, which can give compatible equipment more network choices than a single-network SIM [11][12]. Which network is used depends on coverage, the device radio and the service configuration. It does not create signal where none exists, and SimFalcon says it is not a signal booster [12].

The brand on the SIM matters less than the network beneath it. ComReg says GoMo and Lyca Mobile use Eir’s network, and Clear Mobile and An Post use Vodafone’s, so their 3G follows the host [5].

SimFalcon describes a private APN as being for deployments that need controlled routing or network separation [11]. The OCA recommends that chargers on a VPN or APN mobile network can connect only to the back office, not directly to each other. It also strongly advises against relying on the network alone without TLS, because a misconfiguration or stolen SIM card could leave the back office, and possibly every charger on the network, vulnerable [3]. SimFalcon says it can provide private APN for suitable business deployments, once it understands the charger architecture and back-office destination [11].

Rural sites and underground car parks

ComReg’s map shows predicted outdoor coverage by provider for an address or Eircode [8]. It is a fair first look at a rural site, but because it predicts outdoor coverage it cannot tell you what reaches a basement. Measure where the modem or antenna will sit. ChargePoint’s 2016 make-ready specification, written for North American carriers, says not to rely on phone apps for a signal survey and to take readings at the exact proposed station position. It adds that below-ground or enclosed car parks often need a signal booster, with the outdoor antenna typically at the garage entrance ceiling or on the roof [4].

If you fit a booster, make it a compliant one. ComReg says only repeaters that meet its standards and carry CE marking are permitted, illegal devices will be confiscated where found, and users can be fined [7]. Another layout is one shared site router serving several chargers, with the SIM in the router rather than in each charger [11]. The router’s position then matters for every charger behind it.

3G and 2G: what it means for chargers

Vodafone switched off its Irish 3G network in October 2024. Eir is retiring 3G in phases from 1 October 2026, starting in Donegal [5]. ComReg says the change is not likely to affect Eir customers with a 4G or 5G-enabled device [6]. Check your SIM provider’s own notice, including Three Ireland’s if that is your network.

Two things decide whether this touches a charger: whether its SIM is on Eir’s network (or a brand that runs on it), and whether the charger’s modem has a 4G radio. ComReg says older devices that connect only to 3G and 2G keep making calls over 2G, but data is slower [5]. That is a general description, so ask the manufacturer whether a charger’s OCPP link copes. Designs differ by era: ChargePoint’s 2016 CT4000 specification (a North American product) describes stations that communicate over 3G cellular carriers [4]. Check the data sheet for the radios (2G, 3G, 4G, LTE-M). A new SIM cannot give a modem a radio it does not have, and SimFalcon says device radio capability still matters [12]. Our 3G switch-off guide covers the same check for gates and alarms.

What we could confirm about Irish rules

The two Irish documents we read cover charger design and data supply. Neither sets an uptime percentage like the UK’s 99% rule. This is not a full summary of Irish or EU rules, so check any grant, planning or contract conditions for your own site. A Department of Transport draft strategy quotes Article 20 of the EU Alternative Fuels Infrastructure Regulation. It says that by 14 April 2025 operators of publicly accessible recharging points must ensure static and dynamic data are available, and must set up an API giving free and unrestricted access to it. The draft’s data list includes operational status and availability [10].

Checklist for installers and operators

  1. Record how each charger connects, who supplied any SIM, and whether the SIM sits in each charger or in a shared router [11].
  2. Read the modem’s radios from the data sheet. Flag any 3G-only unit.
  3. Measure signal at the antenna position and write the reading down [4].
  4. Confirm the APN settings and OCPP address with the platform provider.
  5. Agree ping and heartbeat intervals with the platform provider. The OCA suggests 50 to 600 seconds for pings and 300 to 3,600 seconds for heartbeats [1].
  6. At handover, disconnect the charger and confirm that a card used on it before still starts a session. That depends on the authorisation cache or a local list [1].
  7. Monitor pings and heartbeats, and record each outage under a cause such as data communication loss, server down or grid fault [1].
  8. Note what the SIM will be used for, such as telemetry, remote access or payments, because SimFalcon asks for the application type when it quotes [11].

SimFalcon asks for the charger or router model, number of charge points, Eircode or counties, platform if known, and whether the SIM sits in each charger or a shared router [11]. See EV charger SIMs, pricing and coverage.

Sources

Frequently asked questions

Does an EV charger need a SIM card?

Not every charger does. Some use Ethernet or Wi-Fi, while many commercial installations use a built-in cellular modem or a separate 4G or 5G router.

What happens to a charger when its connection drops?

A charger configured for offline use should keep working. Running sessions continue and are reported once the link returns, but new sessions depend on stored authorisations. SEAI's criteria for smart chargers on its home charger grant register require a factory-configured fail-safe mode.

Will the Eir 3G switch-off stop my charger?

Only if its SIM is on Eir's network, or a brand that runs on it, and its modem is limited to 3G or 2G. ComReg says the change is not likely to affect Eir customers with a 4G or 5G-enabled device. A new SIM cannot give a 3G-only modem a 4G radio, so ask the manufacturer which radios it has.

Can I use a signal booster in an underground car park?

Only a compliant one. ComReg says only repeaters that meet its standards and carry CE marking are permitted, and illegal devices will be confiscated and users can be fined. Measure signal at the antenna position first.

Is a multi-network SIM the same as a signal booster?

No. SimFalcon says a multi-network SIM can register on more than one supported network, but it is not a signal booster and does not create signal where none exists.

Questions about connectivity for your equipment? Talk to SimFalcon or ask Engineer Support.

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