BMW i3 REX charging guide

bmw i3 ev charging guide

BMW’s i3 REX is one of the few range-extended plug-in hybrids available in the UK, offering the green motoring of a pure-EV with the back-up of an on-board generator to top up the battery’s charge when required.

Based on the i3 EV, the i3 REX benefits from the model’s battery upgrade in July 2016, improving the official range to 186 miles from the previous generation’s 118 miles. On top of that, a styling refresh has seen a sharper design come through, plus the introduction of a sportier BMW i3s variant.

Official NEDC Range

146 miles
239 miles inc. fuel use

137 miles electric
230 miles inc. fuel use

Real-world Range

117 miles
210 miles inc. fuel use

110 miles electric
203 miles inc. fuel use

How to charge a BMW i3 REX

bmw i3 rex charging

The BMW i3 REX uses the CCS charging standard, which consists of a combined AC and DC inlet port. The top portion of the inlet is for the Type 2 connector, which is used when charging at home or at public slow and fast AC points. The both the upper and lower sections on the inlet are used to carry high power during rapid DC charging. The BMW i3 REX’s CCS charging inlet is found on the off-side rear 3/4 panel where you would expect to find a petrol flap.

The BMW i3 REX is able to be slow, fast and rapid charged from public points, depending on the network and type of charge unit. In most cases, slow charging requires a 3-pin-to-Type 2 cable, and fast charging a Type 2-to-Type 2 cable, one of which is usually supplied with the vehicle. For rapid charging, the vehicle uses a tethered CCS connector which is part of the charging unit.

Type 2 – Slow & FastCCS – Rapid


Charging on AC or DC requires the EV driver to plug the connectors into the correct inlet, after which the car then ‘talks’ to the charging unit to make sure there is a power supply, that there are no faults, and that it is safe to start charging. If charging at private home or workplace charge point, the vehicle then automatically starts charging.

On a public charger, an activation process is required to initiate charging. Depending on the network provider, this may require the use of an RFID card or smartphone app, often linked to an account which has been set up beforehand. Contactless pay-as-you-go units are also becoming more common on newer units. Once activated, the units will conduct further connection and account checks before starting to charge the vehicle.

How long does it take to charge a BMW i3 REX?

bmw i3 rex charging time

The following table shows approximate time to charge a BMW i3 REX 94 Ah. Times are for a 100% charge for all but rapid charging, which is quoted for 0-80% as most rapid chargers reduce or cut power well before 100% charge to protect the battery and maximise efficiency.

Note that the times shown are only a guide, as very rarely will an EV need to be fully charged from 0%. Other factors that might vary the charging time include ambient temperature, in-vehicle energy loads, any upper and lower charge restrictions to extend battery life and protect against potential damage, and charging rates slowing down as the maximum charge is reached.

Rapid 50kWFast 22kWFast 7kWSlow 3kW
35 mins
3 hours
4:30 hours
11 hours

All BMW i3 variants are fitted with an 11 kW on-board charger for AC charging in addition to the Rapid 50 kW DC option. This means that even when connected to a fast charger with a rated output above 11 kW, the BMW i3 will only be able to charge at 11 kW.

Use Zap-Map’s Home Charging Calculator to estimate charging times for a BMW i3 REX. The level of battery charge, connector speed, and on-board charger options can be tailored to your requirements for more accurate results.

How much does it cost to charge a BMW i3 REX?

The table shown below shows estimates of the cost to charge the BMW i3’s 33 kWh battery at home (on a domestic tariff) or using a rapid charge point. Cost estimates are dependent on the charge remaining, usable battery capacity, and age of battery pack. Cost per mile is calculated using an estimate of real-world range.

TypeCost/kWhCost to chargeCost per mile
Home14 p/kWh£4.623.2 p/mile
Public rapid30 p/kWh to 80% charge£7.925.4 p/mile

Based on these figures, the BMW i3’s fuel costs are 3-6 p/mile based on real-world energy usage, the cost depending on the type of charging. In general, home charging provides the cheapest per mile cost and public rapid charging tends to be around double the cost. These fuel costs compare favourably with 12-15 p/mile for conventional petrol and diesel cars.

To find the cost and times to charge an EV on a public charge point, Zap-Map’s Public Charging Calculator calculates charging costs for any new or used plug-in vehicle. The results can be personalised for different electricity costs and the level of charge required.

Charging a BMW i3 at home

bmw i3 rex home charging

Charging at home is often the most convenient and cost effective way to recharge an EV. Government grants are available for the installation of home EV charge points, and a large number of companies offer a fully installed charge point for a fixed price.

Most home chargers are either rated at 3 kW or 7 kW. The higher powered wall-mounted units normally cost more than the slower 3 kW option, but halve the time required to fully charge an EV. Many plug-in car manufacturers have deals or partnerships with charge point suppliers, and in some cases provide a free home charge point as part of a new car purchase.

BMW offers its own home charge unit as well as promoting BP Chargemaster as an official charging partner, with literature and information available from the charge point supplier often found in dealerships.

While buying a BMW home charge point is the easiest option and can be requested at the dealership, Zap-Map recommends shopping about beforehand as there are many other suitable products on the market.

Charging a BMW i3 REX on public networks

bmw i3 rex public charging

The UK has a large number of public EV charging networks, with some offering national coverage and others only found in a specific region. Major charging networks include bp pulse, GeniePoint, GRIDSERVE, InstaVolt, Pod Point and ubitricity.

Payment and access methods across networks vary, with some networks providing an RFID card and others a smartphone app to use their services. While most require an account to be set up before use, some rapid units with contactless PAYG card readers are starting to be installed.

Although many EV charge points are free to use, the majority of fast and rapid chargers require payment. Charging tariffs tend to comprise a flat connection fee, a cost per charging time (pence per hour) and/or a cost per energy consumed (pence per kWh). For more information about network tariffs, visit Zap-Map’s public charge point networks guides.