Buying a used electric vehicle in Australia is one of the smartest moves you can make right now — prices are dropping, the range is improving, and running costs are a fraction of a petrol car. But there's one thing most buyers skip entirely: checking the battery's true health.
The battery is the heart of any EV. A degraded pack means less range, slower charging, and potentially a very expensive repair bill down the track. The good news? With an OBDLink OBD2 adapter and the right app, you can check your EV's battery State of Health (SoH) in minutes — right there in the seller's driveway.
We've put together The Ultimate Used EV Battery Health Guide to walk you through exactly how to do it. Here's a taste of what's inside.
What is Battery State of Health (SoH)?
SoH is the single most important number when evaluating a used EV. It tells you how much of the battery's original capacity remains. A battery at 85% SoH has permanently lost 15% of its range — and that number only goes one direction.
Unlike State of Charge (SoC), which is just the current charge level (like a fuel gauge), SoH reflects long-term degradation. Most EV apps display SoH as a percentage, and some show it in kWh or Ah so you can compare directly to the original rated capacity.
Which OBDLink Tool Do You Need?
Not all OBD2 adapters can read EV battery data. Cheap counterfeit adapters from online marketplaces almost always fail. OBDLink adapters are the gold standard for EV diagnostics — here's how the range breaks down:
- OBDLink MX+ — Bluetooth Classic + BLE, works with iOS, Android, and Windows. The most versatile option and our top recommendation for most EV owners.
- OBDLink CX — BLE only, optimised for iPhone. Great for Nissan Leaf owners using Leaf Spy on iOS.
- OBDLink EX — USB, Windows only. Best for Ford Mustang Mach-E and F-150 Lightning via FORScan.
The Best Apps for Australian EV Owners
The right app depends on your EV:
- Nissan Leaf: Leaf Spy — the definitive Leaf diagnostic app. Shows SoH, cell voltages, capacity in Ah, and charge cycle count.
- Hyundai Ioniq 5/6, Kia EV6: OBD Fusion with Hyundai/Kia EV PID files — excellent coverage of battery and thermal data.
- Tesla: Scan My Tesla — works with OBDLink MX+ and CX. Note that Model 3/Y and post-2021 Model S/X require a Tesla-specific OBD2 port adapter.
- Renault Zoe: CanZE — free and purpose-built for Zoe battery diagnostics.
- BMW i3: BimmerCode — reads detailed battery SoH and cell data.
- MG ZS EV, BYD Atto 3: OBD Fusion or OBDLink App with custom PID files.
What to Look For — Red Flags and Green Lights
Once you're connected and reading data, here's how to interpret what you see:
- SoH above 90%: Excellent — minimal degradation for the age of the vehicle.
- SoH 80–90%: Good — normal for a 3–5 year old EV, price accordingly.
- SoH below 75%: Significant degradation — negotiate hard or walk away.
- Cell voltage spread above 50mV: Red flag — possible weak or failing cell that could cause sudden range loss.
A Special Note on Tesla
Tesla is a unique case. Their vehicles don't support standard OBD2 diagnostics in the traditional sense, and Model 3/Y owners need a Tesla-specific port adapter before connecting any OBD2 tool. Our guide covers all four methods for checking Tesla battery health — from the free Tesla app range check through to the full Tesla Service Battery Report — so you know exactly what you're dealing with before handing over your money.
Get the Complete Guide
The Ultimate Used EV Battery Health Guide covers all of this and more across 9 chapters plus a dedicated Tesla appendix:
- How EV batteries and the BMS work
- Why standard OBD2 isn't enough — and what to use instead
- OBDLink product comparison for EVs
- Step-by-step SoH checking for every major AU EV model
- How to interpret results and negotiate on price
- AU EV compatibility reference (Leaf, Ioniq 5/6, EV6, MG, BYD, BMW i3, Tesla, and more)
- Troubleshooting connection issues
- Long-term battery maintenance tips for Australian conditions
- Full Tesla diagnostics appendix
It's available now as a digital PDF download from Zedmotive — written by our team from real-world experience with Australian EVs.
Download The Ultimate Used EV Battery Health Guide →
And if you need an OBDLink adapter to get started, we stock the full OBDLink range with fast dispatch from Melbourne.
Zedmotive is an authorised Australian OBDLink reseller based in Melbourne, Victoria. 🌐 zedmotive.com.au | 📧 zedmotive@gmail.com
