This is the one most MG owners get wrong, so here it is plainly: MG's Australian high-voltage battery warranty publishes no minimum State of Health percentage. It covers manufacturing defects for 7 years or 150,000 km. It does not promise your battery will still hold any particular proportion of its original capacity.
That is a meaningfully weaker position than Tesla, BYD, Kia, Polestar or Volkswagen, all of which publish a capacity floor. It is not a reason to avoid an MG — the MG4 in particular is a well-regarded car — but it is a reason to test the battery rather than trust the paperwork.
The terms
| First registered | Years | Kilometres | Capacity floor | Transfers |
|---|---|---|---|---|
| On or after 1 July 2025 | 7 | 150,000 km | None published | Warranty runs from first registration irrespective of change of ownership |
| Before August 2024 | 7 | Conflicting — MG's own pages give both unlimited km and 150,000 km | None published | As above |
Note the second row. MG's own published pages disagree with each other on the distance limit for cars retailed before August 2024. We are not going to guess which is right. If you are buying an MG from that period, get the battery warranty terms in writing from MG before you commit.
Applies to MG4, MGS5 EV, MGS6 EV, ZS EV, Cyberster, HS PHEV and MG's hybrids.
The trap in the headline number
MG advertises a 7-year, unlimited-kilometre vehicle warranty, extendable to 10 years and 250,000 km with dealer servicing. That is the number people remember.
The high-voltage battery is not on those terms. It is capped at 7 years and 150,000 km. A widely-circulated Australian comparison site currently states MG's battery warranty as 10 years and 250,000 km — that figure is the vehicle warranty, not the battery, and repeating it will leave an owner believing they have cover they do not have.
What "no capacity guarantee" means in practice
If your MG4's battery degrades steadily to 72% over six years, that is not a defect under this warranty. It is normal wear, and MG has made no commitment about it. You would have a claim only if something failed — a cell fault, a module failure, a BMS defect.
For a buyer, that changes what due diligence looks like. On a Tesla or a BYD you can reason about the distance to the 70% floor. On an MG there is no floor, so the tested figure today, and the trajectory it implies, is the whole picture.
What to check on a used MG
- Date of first registration, which both starts the clock and determines which terms apply
- Whether the car falls into the pre-August 2024 window where MG's own pages conflict
- The tested State of Health, which matters more here than on almost any other brand, precisely because nothing is guaranteed
- Which battery size the car has — the MG4 alone has been sold in Australia with 51, 64 and 77 kWh packs
Terms verified 13 September 2026 from MG Motor Australia's warranty page. Manufacturer terms change, and the terms that apply to any given car are those in force when it was first sold. Always confirm with the manufacturer for the specific vehicle.