Quick answer: Used MG4s in Australia can have quite different batteries: the original 64 kWh and 77 kWh packs use a nickel-based (NMC) chemistry, while the later 51 kWh pack is LFP (lithium iron phosphate). Each ages and should be charged a little differently. MG's warranty terms have changed over time, so check what applies to the specific car. A state-of-health test tells you how that car's battery has actually aged.
The MG4 has been one of the most affordable new EVs in Australia, so it's popular with first-time EV buyers and on the used market. Knowing which battery a car has is the first step.
Which battery is in this MG4?
- 64 kWh (Excite 64 and Essence 64): the MG4 launched in Australia in August 2023 with this NMC battery. More energy, and happiest kept between about 20% and 80% day to day.
- 77 kWh (Essence Long Range): NMC, the biggest battery offered at launch.
- 51 kWh (Excite 51): added to the range later, with an LFP battery. Handles charging to 100% well and generally ages slowly.
MG has changed the line-up since then, so newer cars may have a different battery. The variant name on the paperwork or the compliance plate is the most reliable way to identify the battery.
What the warranty covers
At launch, the MG4 was sold in Australia with a 7-year, unlimited-kilometre warranty covering the body, battery and electronics. MG has since changed its warranty terms for newer cars. Because the coverage depends on when the car was first sold, confirm the battery warranty for that VIN with an MG dealer before buying.
Charging habits by chemistry
- LFP (51 kWh): charging to 100% regularly is fine and helps the car keep its range estimate accurate.
- NMC (64 and 77 kWh): set a daily limit around 80% and charge to 100% when you need the range for a trip.
In both cases, sustained heat while sitting at a high charge is what ages a battery fastest.
Buying a used MG4: what to check
- Variant and battery size (51, 64 or 77 kWh)
- First registration date and the warranty that applies
- How the car was charged: mostly home charging or mostly fast chargers
- Any battery, charging or 12 V battery warnings
- Service history and any software updates done at a dealer
- An independent battery health report
How our battery health check works
We come to the car anywhere within about 60 km of Melbourne's south-east, including the seller's driveway. We read the battery's state of health, every cell group's voltage, module temperatures and stored battery fault codes through the diagnostic port. Nothing is opened up or changed. It takes about 45 minutes, and the plain-English PDF report arrives the same day.
The price is $149 including GST, and you pay after the test. Tell us the exact car when you book and we'll confirm what can be read for it before we come out.
EV Pitstop is an independent business and isn't affiliated with MG.