I bought a brand new MG5 in the UK about a month ago. I’ve been following the general advice of keeping the charge between 20% and 80%.
They say the real-world range for 60% charge is around 105 miles in poor weather (e.g., -10°C with the heater on). But lately, the weather in the UK hasn’t been that bad, and I’m only getting about 70 miles for 60% charge.
I tested this by running the battery down from 80% to 20% without charging in between and keeping track of the miles.
This doesn’t seem normal to me. Should I raise this with MG?
I believe the MG5 uses an LFP battery. With these batteries, you need to charge to 100% occasionally for the car’s battery management system to recalibrate. If you don’t, it might give inaccurate range estimates due to the flat voltage curve of LFP batteries. NMC batteries don’t have this issue.
Try charging to full a couple of times, and the range estimates should improve.
izael said: @olivia
Thanks for the info! But I’m wondering—does not charging to 100% actually affect the real range, or is it just the estimates that are off?
It’s mostly about the estimates. If you don’t charge to 100%, the system might play it safe and underestimate how much range you actually have. There’s a great video by Engineering Explained on this topic—it explains why charging to full occasionally is important, especially for LFP batteries.
izael said: @olivia
Thanks for the info! But I’m wondering—does not charging to 100% actually affect the real range, or is it just the estimates that are off?
LFP batteries can handle full charges better than NMC ones, so charging to 100% regularly isn’t an issue. It’s possible that either:
The car isn’t actually charging to 80% even though it says it is (leading to real range loss), or
It’s charging to 80%, but the system can’t track usage accurately.
In either case, charging to 100% once a week should solve the issue without significantly affecting battery life.
@olivia
Yes, the MG5 has an LFP battery. These definitely need a 100% charge now and then to recalibrate. Also, keep in mind that LFP batteries tend to perform worse in colder weather compared to NMC batteries.
@olivia
This makes sense. NMC batteries have a steeper voltage curve, so it’s easier to tell how full they are. LFP batteries have a flatter curve, so the system struggles to gauge the state of charge accurately. Charging to 100% periodically fixes this.
And don’t worry too much about wear—LFP batteries last longer than NMC ones, even with regular full charges.
@olivia
The battery management system (BMS) uses a model to estimate the state of charge. All lithium-based batteries need occasional recalibration. LFP batteries, in particular, need 100% charges more often (once a week or so) due to their flat voltage curve. For NMC batteries, this might only be needed every 6–8 weeks.
What’s your typical driving routine? Speeds and distances matter a lot.
For example, short trips where you frequently use the heater can really hurt your range. Heating up the cabin takes a lot more energy than just maintaining the temperature. If you’re doing short trips, that energy usage skews the efficiency significantly.
@izael
So about 11 miles/day on average, with half of that being motorway. The motorway trips will reduce efficiency, but the short trips, especially in colder weather, are likely the main issue. The car uses a lot of energy to warm up, especially for those town trips.
Charging to 100% before a longer drive (like the 30-mile trip) is a good idea to reset the system. Maybe try it weekly.
If you’re only doing short trips, your efficiency will drop significantly. For example, driving 2 miles with the heater on uses a disproportionate amount of energy. The car also loses a small percentage of charge while parked, which skews the range calculation further. If you go for a longer drive at steady speeds (40–60 mph), you’ll likely see much better range.
@Imani
Interesting, but I was surprised to see that 4–5 short trips of 4 miles each used up nearly 30% of the battery. I expected closer to 60 miles for 30%, but I only got 20 miles. That seems way off.
@izael
Short trips really skew the numbers. For example, I charged to 80% on Saturday and now I’m at 75% after just a 1.5-mile trip. If I calculated based on that, my range would look like 30 miles instead of 300! But once I do a proper drive (e.g., 50 miles at steady speeds), the numbers balance out.
@Imani
I thought the regen braking on EVs would make short trips more efficient, but in winter, even with mild heating, ICE cars seem to do better for those kinds of drives!