How do you pre heat the battery

[MG4London]

I can’t find the "pre heat the battery" function on any setting.

 

[jpk]

 

[MG4London]

Thanks so much

 

[webhiker]

And in the car under battery consumption

 

[Adam C]

Sorry to jump in here folks

Do people regularly use this feature?

Maybe I should be but I’ve never used it. I only remember seeing one YouTube video where the guy recommended using it if the battery was cold 5-10 minutes before putting it on a fast/rapid charger

The limited times I’ve charged my car it’s always after the car has been driven for a while so battery should be warm

 

[fnegroni]

5-10 minutes would not be enough, for an NMC battery 25 minutes might be just about sufficient to avoid ‘cold gate’. For LFP, more like 40’ or 1h to allow the heat to uniformly distribute throughout the battery pack.
Bear in mind battery heating only prevents cold gate on the MG4, it does not precondition the battery for super fast charging like a Tesla would. It simply ensures the battery is above 10°C (more like 17-20°C) when charged so that it can accept at higher rate from the very beginning.
If you plug in a cold battery the onboard battery heater will kick off anyway but the charge rate won’t be that fast to start with. The act of charging the battery warms it up somewhat too.

Sorry to jump in here folks

Do people regularly use this feature?

Maybe I should be but I’ve never used it. I only remember seeing one YouTube video where the guy recommended using it if the battery was cold 5-10 minutes before putting it on a fast/rapid charger

The limited times I’ve charged my car it’s always after the car has been driven for a while so battery should be warm

NMC battery warms up a little through use.
LFP hardly does.

 

[JonnyG]

I use it occasionally while charging at home for a long trip in cold weather when I want to maximise range.

 

[Adam C]

5-10 minutes would not be enough, for an NMC battery 25 minutes might be just about sufficient to avoid ‘cold gate’. For LFP, more like 40’ or 1h to allow the heat to uniformly distribute throughout the battery pack.
Bear in mind battery heating only prevents cold gate on the MG4, it does not precondition the battery for super fast charging like a Tesla would. It simply ensures the battery is above 10°C (more like 17-20°C) when charged so that it can accept at higher rate from the very beginning.
If you plug in a cold battery the onboard battery heater will kick off anyway but the charge rate won’t be that fast to start with. The act of charging the battery warms it up somewhat too.

Thank you buddy ?

 

[webhiker]

Sorry to jump in here folks

Do people regularly use this feature?

Maybe I should be but I’ve never used it. I only remember seeing one YouTube video where the guy recommended using it if the battery was cold 5-10 minutes before putting it on a fast/rapid charger

The limited times I’ve charged my car it’s always after the car has been driven for a while so battery should be warm

I do it 15-20 mins before I hit a rapid charger. It both heats and cool as needed, I believe

 

[lsb777]

In other similar threads, a lot of people say don't bother in the UK as climate not cold enough. However, if you can use the battery pre-heating whilst still plugged in for a long journey for example, then I'm sure there is some benefit to starting with a warm HV battery as we all know batteries don't like cold weather. Tesla EVs pre-condition their batteries when on way to a SC, so there must be some benefit otherwise why build-in the tech.

 

[fnegroni]

In other similar threads, a lot of people say don't bother in the UK as climate not cold enough. However, if you can use the battery pre-heating whilst still plugged in for a long journey for example, then I'm sure there is some benefit to starting with a warm HV battery as we all know batteries don't like cold weather. Tesla EVs pre-condition their batteries when on way to a SC, so there must be some benefit otherwise why build-in the tech.

On long journeys I always have intelligent heating on.
I also pre heat the battery if I do lots of smaller journeys throughout the day.

 

[WonkoTheSaneUK]

FWIW - on cold days, the car will pop up a message on the touchscreen saying something like:-
"It's cold, would you like to turn on intelligent battery heating?"

 

[lsb777]

On long journeys I always have intelligent heating on.
I also pre heat the battery if I do lots of smaller journeys throughout the day.

I think I switched it on about 45mins away from charging at a Tesla SC when in recent road trip. Didn't want to waste the energy by leaving on for whole journey as battery was in use at motorway speed anyway. Doing another 600 mile round trip on 23/24 March, so might do more tests.

 

[AlunJ]

The few times I’ve tried to use it tells me it doesn’t need preheating. Then it’ll randomly tell me it’s cold and ask to turn preheat on a hot day so god knows what’s going on there ?

 

[jpk]

I tried last week for my commute home from work as it was around 2°C outside and I was curious. It zapped 3% battery and I saw no noticeable difference in efficiency for my 40 mile trip that normally uses 18-20%, but instead cost me 22% overall. Just a sales gimmick re improved efficiency for a journey, maybe benefits rapid charging speeds!

 

[Rolfe]

I have never used it, and it's something I'm really confused about. There was an earlier thread where people tried to explain it, or work their way through their misconceptions, but I never got it clear in my mind. (It was originally split off as a derail from a thread about cabin heating.)

Indications for using battery heating (now the weather is getting colder)

Does the bug affect cabin pre-heat, battery pre-heat or both? I decided to do a battery pre-heat this morning. Started it 90 minutes before departure; app said it was on. Looked again 30 minutes before departure and app said it was off.

www.mgevs.com

When I first got the car the weather was still a bit chilly, but as things warmed up I was occasionally, like @AlunJ, getting random suggestions from the car about pre-heating the battery when the temperature outside was like 17ºC. After a bit I clicked on "don't tell me this again" and it never has, even when it's been below zero.

I know about pre-heating as you approach a DC charger, but how much of your remaining charge is it going to drain, and do you really get enough of a boost in charging speed for it to be worth it? And how long do you pre-heat for (LFP) and how cold out does it have to be before you should do it?

I also know about pre-heating before a long journey in winter, but again, how long for and how cold does it need to be before it's worth it, and how long does the journey need to be before it's worth it? In addition, since my car won't pre-heat when plugged in but not charging, I'm a bit hazy on how I'd even do that. I'd drain a fair bit out of the battery, which really doesn't seem worth it.

But then again I wonder, if I don't do this, am I likely to harm the battery? I honestly don't have a clue.

 

[Adam C]

I have never used it, and it's something I'm really confused about. There was an earlier thread where people tried to explain it, or work their way through their misconceptions, but I never got it clear in my mind. (It was originally split off as a derail from a thread about cabin heating.)

Indications for using battery heating (now the weather is getting colder)

Does the bug affect cabin pre-heat, battery pre-heat or both? I decided to do a battery pre-heat this morning. Started it 90 minutes before departure; app said it was on. Looked again 30 minutes before departure and app said it was off.

www.mgevs.com

When I first got the car the weather was still a bit chilly, but as things warmed up I was occasionally, like @AlunJ, getting random suggestions from the car about pre-heating the battery when the temperature outside was like 17ºC. After a bit I clicked on "don't tell me this again" and it never has, even when it's been below zero.

I know about pre-heating as you approach a DC charger, but how much of your remaining charge is it going to drain, and do you really get enough of a boost in charging speed for it to be worth it? And how long do you pre-heat for (LFP) and how cold out does it have to be before you should do it?

I also know about pre-heating before a long journey in winter, but again, how long for and how cold does it need to be before it's worth it, and how long does the journey need to be before it's worth it? In addition, since my car won't pre-heat when plugged in but not charging, I'm a bit hazy on how I'd even do that. I'd drain a fair bit out of the battery, which really doesn't seem worth it.

But then again I wonder, if I don't do this, am I likely to harm the battery? I honestly don't have a clue.

This morning we left home just before 7am & I received the message about the temperature & would I like to turn on battery heating, I didn’t but weird thing is the outside temperature was 6°

At the weekend I went out, the car was frosted over, temperature 0° & no message about heating the battery but did get the message warning about potential icy roads, odd.

Maybe in future if I go out & it’s freezing conditions, -1, -2° … I’ll stick it on but I think it’s another discussion like the charging, balancing, how often should I 10-100% charge etc no one really knows, not even MG lol

 

[fnegroni]

This morning we left home just before 7am & I received the message about the temperature & would I like to turn on battery heating, I didn’t but weird thing is the outside temperature was 6°

At the weekend I went out, the car was frosted over, temperature 0° & no message about heating the battery but did get the message warning about potential icy roads, odd.

Maybe in future if I go out & it’s freezing conditions, -1, -2° … I’ll stick it on but I think it’s another discussion like the charging, balancing, how often should I 10-100% charge etc no one really knows, not even MG lol

I think the confusion is spreading yet the information is in the manual.

And the reason we have confusion is because we keep doubting the information we receive.
Rant over.

Here it goes:
Once enabled, Intelligent Battery heating reads the battery temperature and if it is at or below 10C it will start heating the battery.

The battery Pre-heating switch on the app will also succeed only if the battery is at or below 10C.

Ambient temperature alone isn't enough to determine if the battery will be pre-heated.

The threshold on the MG4 is the same for both battery types (NMC or LFP).

This information is in the Service Manual.

---

MG knows but wishes to give a plain information that keeps everyone moving and doesn't require you to think because they know that they will warrant the battery and that any discussion about battery longevity is for nerds not for the average Joe.

Nerds come on this forum and we can wax lyrical about how we kept our batteries running for 50 years with only 1% degradation etc... but average joe wants to use the car to get places and MG says "use it and don't worry".

Balancing (or more correctly, Equalisation) happens automatically when you charge both battery types, on NMC it can happen at lower states of charge because of the charge limit you select, but it's only really precise at 100%. LFP only equalises at 100%.

Less than 10% to 100% is to be done once every 3 to 6 months.
It doesn't even say that it has to be done in one go or that it has to be done slowly, but if you are a nerd and you care, the literature from several years experience of Tesla batteries shows that it is good for the BMS to see several states of charge that are stable.
So you can either do what the MG manual says, and you'll be fine (whichever way you carry out the operation) or you can go super nerd and do it like the Tesla Service menu does it. That is covered in links I posted before if you look for them in this forum you will find them. But I might post them again

There's a difference between saying "MG should give us nerds the detailed instructions we crave for" and "MG is not telling us what to do".
The manual says what to do.

 

[Garmor]

Wonder if this helps.

 

[Rolfe]

I think these last two posts epitomise the confusion, for me anyway.

When I got the car I was advised, probably including links to that video, to turn off "intelligent" battery heating to increase range. I thought at the time it worked, but at the same time the weather was getting warmer so who knows.

Then the car started asking me, randomly, if I wanted to switch on battery heating, because the ambient temperature was cold. Except it wasn't. I saw it ask once at 17ºC, but didn't notice it asking when it was actually chilly. Eventually I turned off the notification because it was irritating and seemed pointless.

So I've gone through the winter without turning it on at all.

What about the circumstances outlined in the video? I am probably not going to be approaching a rapid charger at 20-30%. I'm only going to be using a rapid charger on a long trip, and I'm going to minimise my charging stops by going down to around 10%. Do I have power to waste on battery heating? I don't think so. And what's the point in heating the battery when the car is charging? I'm not going to be getting into the car and driving off the minute it has finished charging.

There's a problem there. If I wanted to heat the battery before I set off (presumably this is something for winter, although he doesn't say) I have to unplug the car first. So I'm using range from the battery to heat it. It won't pre-heat when it's plugged in but has finished charging. I don't think I want to lose that range.

So I'm still struggling to envisage a situation where it's to my advantage to heat the battery. But I still wonder if it's bad for the battery not to do it. Except I have no idea when I should be sacrificing range to heat the battery, for its own good.