The 30-second version
- State of Health (SoH) is the key number — the percentage of original battery capacity still usable.
- SoH is a far better indicator of battery condition than odometer reading alone, since degradation depends heavily on charging habits and climate.
- Ask to see the reading directly, from the car's own menu, a manufacturer app, or an independent diagnostic check.
- Most EV battery warranties are tied to the VIN, so they generally transfer to a used-car buyer — confirm the exact remaining cover.
- A full battery replacement outside warranty is a major cost — this check matters more than almost any other on an EV.
Buying a used petrol or diesel car, the engine bay inspection carries most of the mechanical risk. On an EV, that risk concentrates almost entirely in one component: the battery pack. It doesn't have moving parts to listen for or fluids to check the colour of, which makes it easy to skip past — but a tired battery is a genuinely large expense, and the tools to check it properly are more accessible than most buyers realise.
State of Health: the number that actually matters
State of Health (SoH) is expressed as a percentage representing how much of the battery's original capacity is still usable — a battery at 90% SoH holds roughly 90% of the range it offered when new. All batteries degrade gradually over their life; the question for a used EV isn't whether some degradation has happened, but how much, and whether it's proportionate to the car's age and mileage.
How to actually check it
- The car's own infotainment menu — many EVs display a battery health or SoH estimate somewhere in the vehicle settings; ask the seller to show you this directly rather than describing it from memory.
- A manufacturer or third-party app — several EV brands offer companion apps showing battery health alongside charging history.
- An independent diagnostic check — some workshops and EV specialists can run a more thorough battery health assessment as part of a pre-purchase inspection, useful where you want a reading independent of the seller's own device.
Questions to ask the seller
EV battery pre-purchase checklist
- What's the current State of Health reading? — ask to see it, not just be told a number.
- How was the car usually charged? — frequent fast-charging to 100%, versus mostly slower home charging to a partial level, gives a strong clue about likely degradation.
- What's the real-world range now, compared to when new? — a noticeable gap between advertised and actual range is a meaningful signal.
- Is the battery still under manufacturer warranty? — and for how much longer, in both time and distance.
- Any battery-related fault codes or warnings? — worth an independent diagnostic scan if you're unsure.
Battery warranty: does it transfer?
As with a conventional manufacturer's warranty, EV battery warranties in South Africa are generally tied to the vehicle's VIN and a time/distance limit rather than to the original owner, meaning they typically transfer automatically to a used-car buyer. This is genuinely good news for used EV buyers — but "generally" isn't "always," so confirm the exact remaining cover directly with the manufacturer or an authorised dealer using the VIN, rather than relying on the seller's recollection of the original terms.
Other EV-specific things worth a quick look
- Charging port condition — check for physical damage or corrosion, particularly if the car has been charged outdoors in coastal or humid conditions.
- Charging cable(s) included — confirm what's actually included in the sale, since replacements aren't cheap or always readily available locally.
- Software update history — some EVs receive meaningful range and performance improvements via manufacturer software updates; check whether the car is up to date.
Common mistakes
- Judging battery condition by odometer reading alone instead of an actual SoH check.
- Taking the seller's word for the SoH percentage without seeing it displayed directly.
- Not confirming remaining battery warranty cover with the manufacturer directly.
- Overlooking real-world range versus the advertised figure, which can reveal degradation odometer numbers don't show.
Frequently asked questions
Checking an EV on a test drive?
The Test Drive Inspection Guide covers exactly what to check dynamically — including range behaviour, regen braking feel, and warning signs beyond just the battery.
Get the Test Drive Inspection Guide — R75 →This guide is general information for South African motorists, not official confirmation. Battery health tools, warranty terms and degradation patterns vary by manufacturer and model. Always confirm current warranty cover directly with the manufacturer using the vehicle's VIN, and get an independent battery health check where possible before buying.
The RSA Vehicle Guide inspection system covers 60 checks across exterior, engine bay, interior, underbody, test drive and documents — each with red flags, SA repair costs and walk-away triggers.
Get the Complete Inspection Guide Bundle — R299 →