How can you test your EV battery?


You can test your EV battery using specialized tools with the help of a professional, by installing an on-board diagnostic device, or by comparing your car’s real world battery capacity and range to its performance. Solutions like Recurrent Reports are a great and easy tool to help.

Once a battery is in a car, it becomes  hard to get information about its health and performance. Full battery testing requires high voltage training and special lab equipment. However, here are a few things you can try on your own:

Basic testing

  1. Battery Capacity: Evaluating battery capacity involves charging the vehicle for a set duration and comparing the resulting change in battery percentage to the change in battery capacity (State of Charge, SOC). For instance, if we add 33 kWh to a Chevrolet Bolt battery with a capacity of 66 kWh, we should observe a SOC increase of 50% (e.g., from 10% to 60% or from 40% to 90%). Conducting tests across various ranges is crucial to ensure the Battery Management System (BMS) accurately gauges different battery percentages and that the battery receives the expected energy input.
  2. EV Range: While an electric vehicle's range is influenced by factors like driving habits, weather conditions, and terrain, comparing the vehicle's actual range with EPA estimates and historical data specific to your vehicle can offer insights into battery health.
  3. State of Health (SOH): Many EVs feature a built-in battery health monitoring system managed by the BMS. Typically, accessing this information requires an onboard diagnostic device (OBDII reader) to interface with the BMS, providing quantitative data such as battery temperature, voltage, and SOH.
  4. Software Solutions: For existing or accessible EVs, numerous consumer-oriented software tools are available to gather battery information. These tools utilize car data to provide detailed assessments of battery health. Many are tailored to specific brands, such as Tessie or TeslaFi for Tesla vehicles, or LeafSpy for Nissan LEAFs. Recurrent Reports, accessible to most EV drivers and shoppers, offer valuable insights into battery health at no cost.

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