# Connecting an EV charger over 4G

> Check charger platform compatibility, estimate routine data and firmware updates, and test the mobile connection at installation.

Use-case guides · 1 July 2026

For an EV charger connecting to its management platform, UK 4-network 250 MB is a starting plan at £1.20 per active SIM per month. Check the charger supplier's data requirements, particularly firmware downloads, before settling on the allowance. The SIM provides connectivity; the charger and its platform determine which messages and functions use it.

Confirm that the exact charger accepts a separately supplied SIM and lets the installer configure its mobile data connection. If you have one charger or a handful, the [EV chargers sector page](/sectors/ev-chargers) is the relevant starting point.

## Establish the platform connection

Ask the charger supplier which platform the unit should connect to and who controls those settings. Keep that information separate from the SIM's APN. The APN establishes the mobile data connection, while the charger still needs the correct platform configuration.

Before ordering, check the supported SIM format and mobile hardware. A physical ThingSIM is a trio card with mini, micro and nano sizes. An eSIM is supplied as a QR code minutes after ordering, but the charger must support installing it. Both formats cost £2.00 per SIM once.

Agree a commissioning test with the installer and platform operator. The test should show that the platform receives the intended charger information, not just that the charger displays signal bars. Ask the supplier how to verify any other platform functions you rely on.

## Estimate routine data and updates separately

A regular status message and a firmware download are different workloads. Obtain figures for both where possible. If the supplier gives only routine daily data, ask what else might be downloaded or uploaded during maintenance.

This worked example uses assumed values to show the calculation. It is not a usage claim for a particular charger or platform.

| Traffic | Example calculation | Monthly data |
|---|---|---|
| Routine platform traffic | 3 MB a day × 30 days | 90 MB |
| Other maintenance traffic | Assumed monthly amount | 20 MB |
| One firmware download | Assumed file size | 100 MB |
| Total | 90 MB + 20 MB + 100 MB | 210 MB |

A 250 MB plan accommodates that example with 40 MB above the estimate. If the firmware file is 200 MB instead, the total becomes 310 MB and no longer fits. Choose from the available 50 MB, 250 MB, 1 GB and 5 GB allowances using your own figures.

Allow for the possibility that commissioning and normal operation differ. Review the first update separately from an ordinary operating week. [How much data a device needs](/how-much-data-does-my-device-need) explains how to replace assumptions with measured use.

## Commission at the final location

Activate the SIM in the ThingSIM portal when the installer is ready to test. Billing starts that day; SIMs arrive inactive. Enter the APN displayed against the SIM in the charger's supported mobile data settings and save the configuration as instructed by the supplier.

Run the agreed platform test with the charger in its final enclosure and installation position. Keep a record of the SIM reference, charger identifier and platform result. This prevents later confusion when two chargers at the same address have different SIM records.

UK 4-network roams across O2, Vodafone, Three and EE, using whichever is strongest where the device is. Compare [UK 4-network and 3-network](/uk-4-network-vs-3-network) if testing supports a lower-cost three-network option at a fixed site. Do not choose on price alone before testing the installed equipment.

## Decide whether private networking is needed

Every SIM gets a private IP at no charge. That connection cannot accept unsolicited inbound traffic. Ask the platform operator whether the charger initiates the connection it needs or whether the design requires inbound access.

For operators with a defined network design, [private APN](/extras#private-apn), [IPSec VPN](/extras#ipsec-vpn) and [cloud interconnect](/extras#cloud-interconnect) are available extras. Discuss the required connection path before selecting one. A small charger installation does not automatically need private networking simply because it uses a management platform.

A [static public IP](/extras#static-public-ip) is another inbound option at £8 a month per SIM. It is directly reachable from the internet and the customer must secure the device. [Static IP, private APN or VPN](/static-ip-private-apn-or-vpn) helps distinguish these choices.

## Assign usage monitoring

Someone should check the portal before a planned firmware update and review usage afterwards. At the allowance limit the SIM pauses rather than charging overage. You can upgrade immediately, paying only the difference for the rest of the month, or wait for reset.

The portal provides usage and plan changes, and the same controls are available through the [API](/developers/api). Order up to 25 SIMs online by card, with [fleet enquiries](/contact?topic=fleet) for larger deployments. For one or two chargers, a clear record and regular usage review may be all the administration you need.

## Common questions

### Does a charger always need a static public IP?

No. Confirm the platform's connection design first; unsolicited inbound access needs a static public IP or private networking.

### Will 250 MB cover firmware updates?

It depends on the download size and other traffic that month. Add the expected update to routine use before choosing the allowance.

### Does the SIM provide the charger management platform?

The SIM supplies mobile connectivity. Confirm platform access, settings and commissioning with the charger supplier or platform operator.

## Recommended plan

250 MB, UK 4-network: £1.20 a month per active SIM, ex VAT.

Source: https://thingsim.com/ev-charger-4g