Used BMW i3: Battery Degradation What To Expect

The BMW i3 is an innovative electric vehicle that has garnered attention for its unique design and eco-friendly credentials. However, like all electric vehicles, it faces the inevitable issue of battery degradation over time. Understanding what to expect regarding battery health, real-world range, and potential problems can help you make an informed decision when considering a used BMW i3.

Key facts

• The BMW i3 has an MOT pass rate of 89.1%, based on 2,536 DVSA MOT tests.
• The national average pass rate for all models is 79.1%.
• The most common MOT issues for the i3 are tyres (55.3% of defects) and brakes (18%).
• The MOT fail rate for i3s under 40,000 miles is 9%.
• The i3 ranks 20 out of 386 cars by MOT pass rate.

Understanding Battery Degradation

Battery degradation is a natural process that occurs in all lithium-ion batteries, including those used in electric vehicles like the BMW i3. Over time, the battery's capacity to hold a charge diminishes, which can impact the vehicle's range and overall performance. Factors contributing to battery degradation include age, charging habits, temperature extremes, and the number of charge cycles the battery has undergone.

When considering a used BMW i3, it’s crucial to understand how much degradation you might expect. Generally, the i3's battery is designed to retain a significant portion of its capacity even after several years of use. However, it’s not uncommon for a battery to lose around 10% to 20% of its capacity after three to five years, depending on usage and care.

Battery Health: What to Check and Expect

Before purchasing a used BMW i3, checking the battery health is essential. Most sellers should provide a battery health report, but if they don’t, you can request one. This report typically includes details about the battery's current state of charge (SOC), state of health (SOH), and any previous issues.

A healthy battery should ideally have a SOH of 80% or higher. If the SOH is below this threshold, it may indicate that the battery has experienced significant degradation, which could lead to reduced range and performance. Additionally, consider the following:

• Charging History: Ask about the charging habits of the previous owner. Frequent fast charging can accelerate battery degradation compared to regular home charging.
• Battery Temperature: Extreme temperatures can negatively affect battery life. If the vehicle has been regularly exposed to high temperatures, it may have suffered more degradation.
• Warranty: The i3 typically comes with an 8-year or 100,000-mile warranty on the battery. If the vehicle is still under warranty, this can provide peace of mind regarding potential battery issues.

Real-World Range vs Manufacturer Claims

The BMW i3 is marketed with a manufacturer-claimed range of approximately 160 miles on a full charge. However, real-world conditions can significantly affect this figure. Factors such as driving style, terrain, and use of climate control can lead to a more realistic range of around 100 to 130 miles.

For example, if you’re driving in urban areas with frequent stops and starts, you might find that the i3 performs better than on the motorway, where higher speeds can drain the battery faster. Additionally, using the heater or air conditioning can also reduce the range. Therefore, it’s wise to factor in these variables when assessing whether a used i3 meets your daily driving needs.

Charging Costs and Infrastructure

Charging costs for the BMW i3 can vary based on where and how you charge it. If you charge at home, you’ll typically pay around 14p to 18p per kWh, depending on your energy provider. This means a full charge could cost roughly £4 to £6, translating to a cost of about 3 to 5 pence per mile.

Public charging stations can be more expensive, particularly for rapid chargers, which may charge around 30p to 40p per kWh. While these are convenient for long journeys, they can add up quickly if you rely on them frequently. It’s worth checking the availability of charging infrastructure in your area, especially if you live in a flat or a location without dedicated parking.

To find charging points, you can use apps like Zap-Map or PlugShare, which provide real-time information about nearby charging stations. This is particularly useful when planning longer trips or if you’re considering a used BMW i3 that may not have a home charging solution.

Common Problems Specific to the BMW i3

While the BMW i3 is generally regarded as a reliable electric vehicle, there are some common issues that potential buyers should be aware of. Understanding these problems can help you make a more informed decision when purchasing a used model.

1. Battery Degradation: As discussed, battery health is a significant concern. Always check the SOH before buying.
2. Tyre Wear: The i3 is known for its unique tyre specifications, which can lead to uneven wear. Regularly inspect the tyres and ensure they are in good condition, as new tyres can be costly.
3. Braking System: Some owners have reported issues with the regenerative braking system. If you notice any unusual noises or performance issues during a test drive, it’s worth having a mechanic check it out.
4. Electronics: Like many modern vehicles, the i3 features a range of electronic systems that can occasionally malfunction. Ensure that all electronics, including the infotainment system and dashboard displays, are functioning correctly.

Running Cost Savings vs Petrol/Diesel

One of the primary reasons many buyers consider electric vehicles like the BMW i3 is the potential for lower running costs compared to petrol or diesel vehicles. The i3 offers significant savings in fuel costs, maintenance, and tax.

• Fuel Costs: As mentioned earlier, charging the i3 can cost around 3 to 5 pence per mile, while petrol vehicles can average around 12 to 15 pence per mile. This can lead to substantial savings over time, especially for drivers covering long distances.
• Maintenance: Electric vehicles generally require less maintenance than traditional combustion engines. The i3 has fewer moving parts, meaning lower servicing costs. However, keep an eye on the brakes and tyres, as these can wear out faster due to the vehicle's weight and regenerative braking system.
• Tax Benefits: Electric vehicles often benefit from lower road tax rates and exemptions from congestion charges in cities. This can further enhance the savings associated with owning an i3.

Dave's Verdict: Is It Worth Going Electric?

The BMW i3 presents a compelling case for those considering an electric vehicle. Its unique design, impressive technology, and lower running costs make it an attractive option for urban drivers and eco-conscious buyers. However, potential buyers must be aware of battery degradation and the importance of checking battery health before purchasing.

If you’re considering a used BMW i3, take the time to research and understand the vehicle’s history. A thorough check of the battery health, charging habits, and MOT history can save you from unexpected costs down the line. For a comprehensive overview of a specific vehicle, you can use the CarBuyerIQ Vehicle Check to ensure you’re making a sound investment.

In conclusion, the BMW i3 is a solid choice for those looking to transition to electric driving. With careful consideration of battery health and a thorough understanding of the vehicle’s capabilities, you can enjoy the benefits of electric driving while minimising potential pitfalls. Whether you’re commuting to work or exploring the countryside, the i3 can provide a reliable and efficient driving experience. So, is it worth going electric? For many, the answer is a resounding yes.