What is this value and how is it used?
Amber estimates your EV’s usable battery capacity (kWh) using real-world data from your vehicle.
To make Ready By plans accurate, Amber needs a reliable estimate of how much energy your battery can actually store and use. Rather than relying on manual inputs, Amber calculates this automatically using telemetry from your vehicle.
This means your charging plan is based on how your EV behaves in real conditions, not just manufacturer specifications.
Why might this be different from my EV’s listed battery capacity?
There are a few reasons why the value you see in Amber may not match what you expect:
Amber infers your battery capacity.
By analysing how your battery level (SoC) changes relative to energy flowing in and out of the vehicle, Amber is able to estimate your battery capacity. This is different from the Manufacturer “gross” capacity (often quoted in specifications of EVs).
We estimate usable capacity, not total capacity.
EV batteries have buffers at the top and bottom that aren’t accessible for normal use. Amber focuses on usable capacity, which is the portion of the battery you can actually charge and discharge, and therefore the value that matters for planning charging. This will almost always be lower than the advertised battery size.
Battery degradation over time.
All EV batteries will see degradation in usable capacity gradually over time. If your vehicle is older or has high mileage, the usable capacity we observe may be lower than when the car was new.
BMS recalibration and recent usage patterns.
Your car’s Battery Management System (BMS) periodically recalibrates its understanding of the battery. This can cause step changes in reported or observed capacity, especially if the battery hasn’t been charged to high levels and/or driven to low levels recently. Amber’s estimate will adjust over time as new telemetry from your EV is observed.
Data quality and telemetry limitations.
We rely on data recieve via API from your vehicle. In some cases the APIs may not expose exact battery details, short data windows may introduce noise, and early estimates (e.g. within 24 hours of onboarding) may be less precise. To address this, Amber continuously updates the estimate using recent data and improves accuracy over time.
Is this a measure of my battery health?
No.
This value is not a battery health diagnostic.
It is an approximation used to plan charging more accurately and improve your experience with Amber for EVs.
What should I do if the value looks wrong?
If the value seems significantly off, it may correct itself as more data is collected.
You can also contact our EV team by emailing us at ev-support@amber.com.au
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