12th January 2024 News

Why EV battery tests will always be beneficial

Why EV battery tests will always be beneficial.

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Why EV battery tests will always be beneficial
21st December 2023 News

Access to the used EV market

Ensuring everyone can buy a used EV with confidence will depend on knowing about battery health.

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Access to the used EV market
12th December 2023 News

Ensuring a fair and equitable transition to clean transport

How battery health testing helps ensure a fair and equitable transition to clean transport.

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Battery health refers to the overall condition and performance of a vehicle’s battery. It’s a measure of how well the battery can store and deliver electrical energy compared to its original capacity and performance when it was new. Battery health is an important consideration because it directly impacts the longevity and range of the vehicle and therefore affects how much it is worth to buy and sell.

A battery health certificate gives peace of mind in a similar way to an MOT and helps assess the value of a vehicle when buying, selling or reviewing service plan options. Unlike an MOT certificate a Battery Health Certificate does not show a pass or fail – it shows how healthy the battery is and how it compares to other vehicles.

The battery health certificate only relates to the vehicle’s battery, and no other parts of the car such as the brakes, or body work.

All other aspects of a vehicle apart from the battery will still need to be subject to an MOT. Because an MOT will not measure the battery’s health, a battery health certificate is an ideal document to accompany an MOT for anyone looking to buy or sell a used electric vehicle.

Altelium’s proprietary test works by collecting data from the battery and vehicle, and using this information to estimate the health of the battery. Using powerful data analytic processes these datasets are cross referenced with modelled and real world battery performance data to reveal whether the battery is likely to be reliable in the future.

Modelling battery performance is an essential step to inform extended warranties or other financial or service solutions, to allow informed decision-making when buying or selling the vehicle.

All EV batteries suffer from degradation. There are several different mechanisms of degradation, including ‘calendar’ ageing that occurs over the course of time and ‘cycling’ ageing which occurs as a result of the battery being charged and discharged. Rates of degradation vary depending on many factors, including how the vehicle is used / charged so it’s not always easy to tell whether a battery is showing signs of abnormal degradation. The Altelium battery health test provides a way to verify the battery degradation of a vehicle before purchase.

The lithium-ion chemistry in batteries varies according to the preferred balance between energy density, cycle life, safety, and cost-effectiveness. The most common lithium-ion battery chemistries in electric vehicles are:

Lithium Nickel Cobalt Manganese Oxide (LiNCM or NMC)
Lithium Iron Phosphate (LiFePO4 or LFP):
Lithium Nickel Cobalt Aluminum Oxide (LiNCM or NCA)

Any one vehicle will always have the same type of chemistry in its battery cells, but the chemistry can vary between models and makes. Battery health tests, such as Altelium’s will take this into account and will also be updated as new vehicles are released with different battery chemistries.

The main factor to be aware of is whether the batteries in your vehicle are LFP. In this case you will need to charge the vehicle to 100% on a regular basis in order to rebalance the cells.

A high mileage EV is not necessarily something to worry about it, what matters is the health of the battery. Altelium’s battery dealer test and certificate will tell you all you need to know in this respect.

The size of the battery has a big impact, so a car with a big battery and 100,000 miles on the clock is likely to be in better shape than a car with the same mileage but a smaller battery. However, a battery health check will always be important, regardless of size. You don’t want a large battery that is showing signs of serious degradation. An Altelium battery dealer test and certificate will tell you whether that battery is doing better or worse than expected for the mileage and help guide your decision-making.

Because vehicle battery cells involve chemistry, temperature has an effect on the battery health.  High temperatures can cause accelerated degradation, while extreme cold can temporarily reduce battery performance. Most electric vehicles have a thermal management system to maintain the battery within an optimal temperature range during operation and charging. If you can, avoid exposing your EV to extreme temperatures as much as possible, for example on a very hot and sunny day, try and park your car in the shade.

The state of charge indicates how much energy is currently stored in the battery as a percentage of its maximum capacity. Keeping a battery within a healthy SoC range can help prolong its life. Your vehicle will have a battery management system which is designed to protect the battery from serious damage, but you can prolong its life by keeping the battery between 20% and 80% charge as much as possible.

Battery capacity refers to the amount of electrical energy a battery can store and deliver when fully charged. In vehicles it is measured in watt-hours (Wh). As a battery ages, its capacity very gradually decreases. A battery with reduced capacity will run out of charge more quickly, leading to shorter usage time or range between charges.

All electric vehicles have a battery management feature or operating system. It is a crucial hidden component which maintains the performance, safety, and longevity of the batteries. The BMS will vary between manufacturers and models and will come with varying degrees of sophistication, but a crucial role for all of them is thermal management. The BMS monitors the temperature of each cell and can activate cooling or heating systems to keep the cells within an optimal temperature range. This ensures that each cell within a battery pack operates within safe limits and helps maximize the overall efficiency and lifespan of the battery system. The BMS will also protect the battery by ensuring the vehicle is not overcharged, and may sometimes disconnect from the charger if necessary.

Range will be affected by the energy available from the battery, (which is itself affected by the outside temperate and the normal degradation of the battery), driving efficiency, and additional energy being used by the vehicle such as aircon and heating. In cold weather it is normal for the maximum range of an EV to reduce by between 10% to 30%.

On-board diagnostics (OBD) refers to the automotive system that monitors and reports the performance of various major systems of a vehicle, including the battery.

On board diagnostics became mandatory in all vehicles from 1996 in the US and 2003 in the EU and UK.  All electric vehicles use the advanced OBD II protocol.

OBD systems play a crucial role in vehicles by providing real-time monitoring, with the ability to detect and diagnose malfunctions and optimise performance and vehicle safety.

OBD stands for On-Board Diagnostics. To run the Altelium battery health test you need an Altelium OBD device to plug in to the vehicle’s OBD II port.  Altelium’s OBD device is small, just 6 cm x 4 cm x 2 cm,  and fits into the palm of a hand.

The Altelium OBD device has a standardised 16 pin connector at one end which plugs into the vehicle’s OBD II port, and communicates between the vehicle and the Altelium platform via its built-in SIM card.

The location of the OBD II port varies according to the vehicle make, model  and age. It may be protected from dust and dirt with a cover which can be lifted by hand.

In some EVs such as the first generation Renault Zoe the OBD II port it is in the central console between the front seats, below the dashboard. For later generations of Renault Zoe, the OBD II port can be found by the accelerator pedal in the driver’s footwell.

In other vehicles such as the Vauxhall Corsa-e or BMW i7 it is located on the passenger side, under the footwell or inside the glovebox for right hand drive (RHD) vehicles.

In most vehicles the OBD II port can be found under the steering wheel or further down, below the steering rack – these can usually be easily be found.

Instructions on how to find the OBD II port in your vehicle can be found in the vehicle’s instruction manual, searching for ‘OBD II port’


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