Know exactly what your Leaf's battery is doing
A comprehensive in-depth state-of-health test (not just a Leaf Spy) and a printed report, capacity, cell balance, bar loss and the range you'll actually get. Independent, and done by people who read these packs every week.
What we actually measure
The dashboard capacity bars only tell part of the story, and the "SOH" figure a phone app shows can be misleading on its own. We connect to the battery management system using proprietary diagnostic software and read it properly:
- State of health (SOH), usable capacity now versus when the car was new, as a percentage
- Capacity bars, how many of the twelve are left, and how close the next one is to dropping
- Cell-pair voltages and balance, the real tell-tale. A weak or drifting cell group is a bigger problem than a slightly lower SOH
- Ahr / capacity number, the raw figure the car stores, tracked over time if you come back
- Estimated real-world range at 100% for your battery, in NZ conditions, motorway and town
- Any stored battery fault codes and charging history flags
- Charging and cell temperature history, understand how your Leaf has been charged and any high temp events
You leave with a one-page report you can keep, show a buyer, or send to an insurer.
When a battery check is worth it
Before you buy
The one check that matters most on a used Leaf. Two cars the same year and price can be worth thousands apart once you see the battery.
Before you sell
A good report is a selling point. A written SOH figure builds trust and stops buyers low-balling on a guess.
Range has dropped
If your Leaf suddenly won't go as far, we'll tell you whether it's the battery, your driving conditions, or something else.
You just want to know
Track your pack over the years. We'll log it each visit so you can see the trend, not just a single snapshot.
What's normal for each battery
Every Leaf loses some capacity; that's chemistry, not a fault. Rough guide to what we'd expect on a well-kept ex-Japan car:
- Gen 1 Leaf ZE0 24 kWh (2011–2012): most now sit around 30 to 40% capacity, three to five of the twelve bars. Realistically a 30 to 50 km car, and the pack is usually the deciding factor on whether to keep it.
- Gen 2 Leaf AZE0 24 kWh & 30 kWh (2013–2017): ahead of the ZE0, and later cars on the revised chemistry hold up best of the two pack sizes. Early 30 kWh packs reported degradation wrongly until a Nissan software campaign; some still show pessimistic numbers, so we read the true figure.
- ZE1 40 kWh Leaf (2017–2024): holding up well, typically high-70s to high-80s%. Watch for heat effects rather than age.
- ZE1 e+ 62 kWh Leaf (2019–2024): generally excellent, often 90%+.
What we're really looking for is whether the number matches the car, a 2020 40 kWh Leaf showing 24 kWh-car degradation is telling us something.
30 kWh Leafs: when the cells get tired
A 24 kWh pack mostly just loses capacity as it ages and otherwise stays well behaved. A heavily worn 30 kWh pack (the 2016 and 2017 cars) ages differently. As well as losing capacity, its cells develop high internal resistance, which means they lose the ability to deliver power as well as the ability to store it. Cycle count matters more on the 30 kWh than it did on the 24 kWh, so the odometer is a better guide to the pack than the age of the car.
Around town a tired 30 kWh can still be a perfectly good commuter, as long as you know its limits. Where it shows is at open-road speed or on a steep hill, when the car can go from showing plenty of range to almost none, or drop into turtle mode, very quickly.
The battery controller keeps a figure for this, the internal resistance coefficient, often called Hx in the Leaf community. It starts at 100% on a new pack and falls as resistance rises, and we record it as part of a 30 kWh battery check. What it tends to look like:
- High 30s (commonly on packs that have done 100,000 to 150,000 km): the state-of-charge display drops suddenly when you go from gentle to hard driving, and jumps back up when you ease off.
- Low 30s or high 20s (commonly past 150,000 km): under load the range can fall from plenty to turtle mode very quickly, particularly on the open road or on hills.
Because the coefficient is calculated across the whole pack, a few bad cells won't drag it down. A low number therefore means most of the cells are tired, and replacing or upgrading the pack usually makes more sense than repairing it. A car with a decent coefficient that still has these symptoms may well have a small number of failing modules, and in that case replacing just those modules can be worth doing.
Buying a 30 kWh Leaf? This is the check to get done first. Book a battery health check, or see the battery repair and upgrade options if yours is already showing these signs.
If the battery does need work
We're not here to scare you into a new pack. Depending on what we find we can:
- Replace individual weak modules or cells to rebalance a pack that's mostly healthy
- Fit a refurbished or higher-capacity pack (including 24 → 30 / 40 kWh upgrades on suitable cars)
- Sort charging and BMS faults that look like battery degradation but aren't
- Give you an honest "this one's not worth it" if that's the answer
Frequently asked
How long does it take?
The check itself is quick, usually under an hour. Book ahead and you can wait in the lounge. Bring the car with at least half charge if you can.
Is it the same as LeafSpy?
We use professional tools plus cell-level data. LeafSpy is a great owner app, but a dongle reading on a phone isn't a document a buyer or insurer will accept, and it won't interpret what the numbers mean for your car.
Do I need to own the car?
No. If you're buying privately, arrange with the seller to bring it in, or send them to us. Plenty of Leaf sales get checked here first.
Book a Leaf battery health check
Fixed price, printed report, no upsell. Included free when you book a full service at the same time.
Booking request
We reply within the hour, Mon–Fri 7:30am–5pm.
Urgent? Call 09 579 6083 or text 021 184 7876.