MG MG4 or BYD Dolphin: the batteries compared
What the advert doesn’t say: capacity by version, the manufacturer’s warranty, and what a failure would cost.
The essentials
- Longest warranty: BYD Dolphin, 8 years or 155,343 miles, against 8 years or 100,000 miles (MG MG4).
- Cheapest to charge: BYD Dolphin, from £6.73 per 100 miles at home, against £6.78 (MG MG4).
- Module-by-module repair: feasible on none of these models.
Side by side
| Criterion | MG MG4 | BYD Dolphin |
|---|---|---|
| On sale | since 2022 | since 2023 |
| Battery capacity | 50.8 kWh, other versions not recorded | 60.4 kWh |
| Chemistry | LFP, NMC | LFP |
| Battery warranty | 2022 – 2023: 7 years or 80,000 miles guaranteed capacity: 70% since 2024: 8 years or 100,000 miles guaranteed capacity: 70% | 8 years or 155,343 miles guaranteed capacity: 70% |
| Repairable module by module | No | No |
| Replacing one module | — | — |
| New pack, order of magnitude | Not recorded | Not recorded |
| WLTP consumption | 3.3 – 3.9 miles/kWh | 3.9 miles/kWh |
| Home charging, per 100 miles | £6.78 – £9.90 | £6.73 – £8.42 |
| Battery lease | Never | Never |
| Going further |
Capacity: every version sold under that name. Warranty: terms recorded for the UK, by year of first registration. Prices: orders of magnitude recorded in France, in euros, never quotes. Charging: from the most frugal version on the cheapest tariff to the thirstiest in real-world use.
Before you choose
A table compares models; you buy a car. Capacity depends on the version, the warranty on the date of first registration, and the state of health on the life the battery has had. The checker answers for one specific car: remaining warranty, expected state of health, cost of a failure.