The Seal uses BYD's Blade lithium-iron-phosphate pack, the same chemistry family as the Atto 3 but substantially larger. LFP is the more durable mainstream EV chemistry — it tolerates being charged to 100%, handles heat better than nickel chemistries and loses capacity more slowly. A two or three-year-old Seal measuring in the low nineties is behaving exactly as it should.
The packs Australia got
| Variant | Years | Usable kWh | Claimed range | Real-world consumption |
|---|---|---|---|---|
| Dynamic | 2024–2026 | 61.4 (63.0 gross) | 460 km | 16.8 kWh/100km — modelled |
| Premium (RWD) | 2023–2026 | 82.5 (84.0 gross) | 570 km | 17.2 kWh/100km — modelled |
| Performance (AWD) | 2023–2026 | 82.5 (84.0 gross) | 520 km | 18.5 kWh/100km — modelled |
The Dynamic and the Premium are separated by 21 kWh of usable capacity — a third of the smaller pack again. In a used listing they are both "a BYD Seal". Identify which one before you interpret any figure, and before you agree a price.
What normal looks like, and why range still disappoints people
At a modelled 17.2 kWh/100 km, a healthy 82.5 kWh Premium returns roughly 480 km in real-world conditions against its 570 km claim. That is a normal test-cycle gap, not a fault.
Apply capacity loss to the real figure rather than the claim. At 92% State of Health you are at about 441 km; at 85%, about 408 km. Because the Seal starts with a genuinely large pack, it absorbs degradation better than a short-range car — a 10% loss on a Seal still leaves more usable range than a healthy Atto 3 ever had.
That is the practical argument for a big battery on the used market: not that it degrades less, but that the same percentage costs you less that you will actually notice.
Why LFP still needs testing
LFP's durability is an average, not a guarantee for the car in front of you. Three things still vary between individual Seals: how often it was DC fast-charged, whether it lived somewhere hot, and whether any individual cells have drifted out of balance. The last one is invisible in a single State of Health figure and is precisely what a cell-level read is for.
There is also a quirk worth knowing: LFP packs are harder for a battery management system to estimate accurately mid-range, because the voltage curve is so flat. That is why BYD, like Tesla on its LFP cars, wants a periodic full charge — it lets the system recalibrate. A Seal that has never been charged to 100% may report a less reliable figure than one that has, which is the opposite of the advice you would give for a nickel-chemistry car.
Warranty position
8 years or 160,000 km, 70% capacity guaranteed, transferable, and backdated to every BYD sold in Australia since August 2022. Full terms: BYD battery warranty in Australia.
What to check before you buy
Which variant — 61.4 or 82.5 kWh usable, a difference that dwarfs any degradation question
Measured State of Health, expecting low nineties on a car under four years old
Cell voltage spread, the thing a single figure hides
DC fast-charge frequency and where the car has lived
Whether it has had a recent full charge, for the reason above
Capacity data verified 13 September 2026. Consumption figures marked "modelled" are EV Database estimates rather than physical tests.