Both MG S5 EV batteries are lithium-iron-phosphate, which is the most durable mainstream chemistry and the one least bothered by full charging. That is the good news. The rest of the picture needs care: MG quotes 49 and 62 kWh without saying whether those are usable or gross, and MG's warranty — 7 years, 150,000 km — publishes no capacity guarantee at all.
The packs Australia got
| Variant | Years | Battery (as quoted by MG AU) | Claimed range (WLTP) | Real-world consumption |
|---|---|---|---|---|
| Excite 49 / Essence 49 | 2025–2026 | 49 kWh — usable/gross not stated | 340 / 335 km | No independent figure |
| Excite 62 / Essence 62 | 2025–2026 | 62 kWh — provisional: 62.1 usable / 64.0 gross | 430 / 425 km | No independent figure |
The 62 kWh figure is the one to watch. Other markets quote this pack as roughly 64 kWh gross, which would make MG Australia's 62 a usable number — but MG has not said so, and we have marked it provisional rather than assume. The Essence grades lose about 5 km of claimed range to larger wheels.
What "no capacity guarantee" means for you
MG's terms cover the battery against defects for 7 years or 150,000 km on cars first registered on or after 1 July 2025. What they do not do is name a percentage below which MG will act. Most rivals publish 70%. MG publishes nothing, which means a gradual loss of capacity is not, on the published terms, something you can point to a number and claim against.
The practical consequence: a dated, independent measurement of the pack matters more on an MG than on a BYD or a Tesla, because if you ever need to argue that the battery has lost more than it should, you are building a case rather than comparing against a published floor. Full terms, including the older-car kilometre conflict: MG battery warranty in Australia.
LFP and the charging question
Because both packs are LFP, a seller who charged to 100% every night was doing what MG recommends. Do not treat it as a warning. What is worth knowing is whether the car has had a full charge recently, because the battery management system's state-of-charge estimate on a flat-curve chemistry is only as good as its last calibration.
What to check before you buy
Which pack — 49 or 62
Measured State of Health and cell voltage spread, since there is no published floor to compare against
First registration date against 1 July 2025, which determines which MG terms apply
Whether it has had a recent full charge
MG4 · MG ZS EV · Book a test — $249
Battery figures as quoted by MG Australia, chemistry as reported by Australian launch coverage. The 62 kWh usable/gross split is provisional. Verified 15 September 2026.