Our extended warranty cost-benefit piece covers the insurance side of battery risk — what it costs to protect yourself against a bad pack. This one is about the flip side: how battery health, expressed as state-of-health (SOH) percentage, actually translates into dollars when a used EV changes hands, and why "the battery still works fine" isn't the same question as "what should I pay for it."

Quick answer: A used EV's resale value tracks its battery's state of health in fairly predictable bands: 95-100% SOH sells at or above baseline market price, 90-94% SOH is generally market-aligned with no meaningful discount expected, 80-89% SOH typically commands a 5-15% discount, and below 80% SOH pricing gets steep and increasingly governed by the cost of an eventual battery replacement rather than the car's nominal specs. Overall, moving from a "good" battery to a "poor" one can shift a used EV's resale value by 20-40%. In the Canadian market specifically, most EVs hold up well early — 95-98% capacity retained at 50,000 km, 90-95% at 100,000 km for a healthy pack — but depreciation overall is steep regardless of battery health, with 2022-2023 model-year EVs having hit what one analysis calls a "depreciation cliff," down 35-55% from original MSRP.

The state-of-health-to-price relationship, band by band

Battery degradation isn't a cliff — it's a gradual capacity loss, typically measured as state of health, the percentage of a battery's original rated capacity it can still deliver. But the price impact isn't perfectly linear, because buyers (and the market pricing algorithms increasingly used by dealers and marketplaces) treat certain thresholds as meaningfully different risk categories:

  • 95-100% SOH: Effectively as-new performance. These cars sell at or slightly above baseline market pricing for their age and mileage — buyers pay a premium for documented, near-original battery health.
  • 90-94% SOH: Still considered normal, expected degradation for a car of typical age and mileage. Generally no discount required; this is where most healthy, moderately used EVs land.
  • 80-89% SOH: This is where real pricing pressure starts. Range loss becomes noticeable in daily use, and buyers reasonably start asking questions. Expect roughly a 5-15% discount versus a comparable higher-SOH example.
  • 70-79% SOH: Discounts get steep here, and for good reason — a car in this range is approaching (or has already crossed, depending on the automaker's own warranty threshold) the point where a battery replacement becomes a live financial consideration rather than a theoretical one.
  • Below 70% SOH: At this point, the car's resale value is effectively governed less by its overall condition and features and more directly by the cost of eventually replacing the battery — the vehicle is being priced closer to "parts car plus a working drivetrain" than a normally functioning used car.

What this looks like with real Canadian numbers

Canadian used-EV pricing data shows the deprecation pattern clearly, separate from the SOH question but closely related to it. By age: year-1 EVs (roughly 0-20,000 km) depreciate 5-15% from new; year-2 cars (20,000-50,000 km) are down 15-25%; by year-3-plus (50,000+ km), depreciation reaches 35-55% from original MSRP — a range wide enough that battery health, documented or not, is clearly one of the things driving where a given car lands within it.

Model-specific two-year retention figures illustrate the spread: a Tesla Model 3 retains roughly 52-62% of its value at the two-year mark (a per-10,000 km depreciation of about $1,100), a Model Y holds 67-69% (about $900 per 10,000 km), a Hyundai Ioniq 5 sits around 72% (about $1,200 per 10,000 km), and an Ioniq 6 — new enough that data is still thin — around 78%. The battery health data underlying this: a well-maintained pack typically retains 95-98% of its original capacity at 50,000 km and 90-95% at 100,000 km, meaning a car with meaningfully worse retention than that at a given mileage is a real red flag worth negotiating on, not just a curiosity.

Regionally, Canadian used-EV pricing also varies independent of battery health: Alberta and the Prairies tend to run 5-12% below the Ontario baseline for comparable vehicles, while British Columbia commands a 3-5% premium — worth knowing so you don't mistake regional pricing variance for a battery-health signal, or vice versa.

How to actually check state of health before you buy

None of this pricing logic is useful without a real SOH number, and this is where a lot of used-EV shopping goes wrong: a seller's word, or an assumption based on range shown on the dash, isn't the same as a verified figure. A proper battery health check — via the automaker's own diagnostic tool, a third-party service, or in some cases a built-in app reading — gives you an actual SOH percentage you can weigh against these pricing bands, rather than negotiating blind. Treat "I haven't had it checked" the same way you'd treat a used gas car with no service records: not necessarily a problem, but a real unknown that should be priced in until it's resolved.

Why this matters more for older, higher-mileage EVs

The pricing-band effect compounds with age for a simple reason: as more of the used-EV market ages into the 80,000-150,000 km range, the gap between a well-maintained pack and a genuinely degraded one widens, and buyers are increasingly comparing specific SOH numbers rather than just model and mileage. A car with excellent documented battery health at high mileage can outsell a lower-mileage example with an unverified or poor SOH reading — which is exactly why getting (and keeping) a battery health report is worth treating as a value-protecting step, not an optional extra, if you're planning to sell a used EV down the road.

The bottom line

Battery health isn't just a range question — it's a direct, fairly predictable input into resale value, with SOH in the 90%+ range holding value normally, the 80-89% band costing you a real 5-15%, and anything below 80% shifting the conversation toward battery-replacement economics rather than normal used-car pricing. Combine that with Canada's already steep overall EV depreciation curve (35-55% by the three-year mark) and a documented, verified SOH reading becomes one of the highest-value pieces of information you can get — as a buyer trying not to overpay, or a seller trying not to leave money on the table.

FAQ

How much does battery degradation actually lower a used EV's resale value? Moving from a well-maintained ("good") battery to a genuinely degraded ("poor") one can shift resale value by 20-40%, with the steepest discounts kicking in once state of health drops below about 80%.

What state of health percentage should I expect on a used EV? For a healthy pack, roughly 95-98% capacity retained at 50,000 km and 90-95% at 100,000 km. Meaningfully worse than that at a given mileage is worth negotiating on.

Does battery degradation affect all EV models the same way? No — retention varies by model. Canadian two-year retention data shows real spread, from roughly 52-62% (Tesla Model 3) up to about 78% (Hyundai Ioniq 6), independent of battery-specific SOH differences within any single model.

How do I actually find out a used EV's state of health before buying? Through the automaker's own diagnostic tool, a qualified third-party battery health check, or in some cases an in-app reading — don't rely on a seller's description or the range shown on the dash alone.

Sources: Recharged, "Does Battery Health Affect EV Resale Value? 2026 Guide"; CarDog, "Used EV Prices Canada 2026: Tesla and Hyundai Depreciation Analysis". The percentage-discount bands are a general industry pattern rather than a fixed formula — actual pricing varies by model, market conditions, and individual buyer risk tolerance.