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

[siteguru]

After a year of ownership I think it is typical for the LFP pack (in the MG4) to show 95% SOH ... mine was the same with only 5k miles on the clock.

 

[fnegroni]

Thanks for this. I’ve only had the car about a week so just getting used to things. I’m currently averaging about 3.2 on a 22 mile journey to work, but it takes about 3 miles for it to start averaging things out. I didn’t know if pre-heating the battery helped with me getting a better M/kwh.

Preheating the battery will help with the efficiency of the power delivery from the battery and avoid sudden power drops at lower states of charge. It’s there to ensure you get the best performance from the battery at lower temperatures, but it will only be available if the outside temperature is below 10 Celsius. I tend to leave intelligent battery heating on during longish (80+ miles) journeys: if it’s warm it won’t come on, if it were cold at the start I’ll have preheated the battery anyway, and if it gets cold during the journey then it will ensure the battery stays warm.

As for short journeys, depends if I’m likely to do hard accelerations from the start or whether it’s freezing. I noticed for example that when charging the battery at home using the granny charger, if it’s below freezing I’m better off pre heating the battery or only charge to 90%.

 

[Adammac39]

Thankyou, all great information!! What’s the best mode to drive in? I’m presuming eco?

 

[JonnyG]

Preheating the battery will help with the efficiency of the power delivery from the battery and avoid sudden power drops at lower states of charge. It’s there to ensure you get the best performance from the battery at lower temperatures, but it will only be available if the outside temperature is below 10 Celsius. I tend to leave intelligent battery heating on during longish (80+ miles) journeys: if it’s warm it won’t come on, if it were cold at the start I’ll have preheated the battery anyway, and if it gets cold during the journey then it will ensure the battery stays warm.

As for short journeys, depends if I’m likely to do hard accelerations from the start or whether it’s freezing. I noticed for example that when charging the battery at home using the granny charger, if it’s below freezing I’m better off pre heating the battery or only charge to 90%.

Yes I totally agree with that . Today I had a 100 mile return trip and charged to 90% overnight. 90 minutes before setting off I started the charge to 100% and turned on battery heating (which actually came on from the app at 4c this time!). Half an hour before setting off I preheated the cabin too.

The power and efficiency on setting off was far better than usual (i.e. without preheating anything). The trip returned good mls/kwh considering I wasn’t hanging about in ECO or anything on the motorway.

 

[siteguru]

Thankyou, all great information!! What’s the best mode to drive in? I’m presuming eco?

It depends how heavy / unrefined your right foot is. The different modes essentially just lag the throttle response to varying degrees. You can get as good efficiency in Sport as you can in Eco, provided you have a cultured right foot.

On longer, motorway journeys you're better using Regen level 1, to avoid slowing down too much and losing momentum. (It takes more power to get back up to speed than is recovered by regen).

 

[Rolfe]

Preheating the battery will help with the efficiency of the power delivery from the battery and avoid sudden power drops at lower states of charge. It’s there to ensure you get the best performance from the battery at lower temperatures, but it will only be available if the outside temperature is below 10 Celsius. I tend to leave intelligent battery heating on during longish (80+ miles) journeys: if it’s warm it won’t come on, if it were cold at the start I’ll have preheated the battery anyway, and if it gets cold during the journey then it will ensure the battery stays warm.

As for short journeys, depends if I’m likely to do hard accelerations from the start or whether it’s freezing. I noticed for example that when charging the battery at home using the granny charger, if it’s below freezing I’m better off pre heating the battery or only charge to 90%.

Thanks for that.

 

[tsedge]

It depends how heavy / unrefined your right foot is. The different modes essentially just lag the throttle response to varying degrees. You can get as good efficiency in Sport as you can in Eco, provided you have a cultured right foot.

On longer, motorway journeys you're better using Regen level 1, to avoid slowing down too much and losing momentum. (It takes more power to get back up to speed than is recovered by regen).

Adaptive regen is also worth a try, it has less regen at high speed and is my preferred mode.

Preheating the battery will help with the efficiency of the power delivery from the battery and avoid sudden power drops at lower states of charge. It’s there to ensure you get the best performance from the battery at lower temperatures, but it will only be available if the outside temperature is below 10 Celsius. I tend to leave intelligent battery heating on during longish (80+ miles) journeys: if it’s warm it won’t come on, if it were cold at the start I’ll have preheated the battery anyway, and if it gets cold during the journey then it will ensure the battery stays warm.

As for short journeys, depends if I’m likely to do hard accelerations from the start or whether it’s freezing. I noticed for example that when charging the battery at home using the granny charger, if it’s below freezing I’m better off pre heating the battery or only charge to 90%.

I wonder if this is characteristic of the SR?

With mine I have never preheated and though I have experienced lower rapid charge rates when the battery is cold I have never had power restrictions even when below zero outside (get 100% power available always). Perhaps the NMC chemistry copes better in these circumstances? Or maybe the software control system is just more mature because the technology is older?

I am not knocking the SR in any way, I think it is a great option and would have had one if available in Trophy trim.

 

[fnegroni]

I wonder if this is characteristic of the SR?

With mine I have never preheated and though I have experienced lower rapid charge rates when the battery is cold I have never had power restrictions even when below zero outside (get 100% power available always). Perhaps the NMC chemistry copes better in these circumstances? Or maybe the software control system is just more mature because the technology is older?

I am not knocking the SR in any way, I think it is a great option and would have had one if available in Trophy trim.

X-power drivers have experienced power limits when the battery is cold.
I’ve never experienced power limits myself and I don’t think most people will have noticed even if they had.
But then a year old battery is relatively new, with a high state of health and low degradation.
I think generally speaking the benefits of battery heating is mostly noticed when charging.
Yet I think it’s worth considering heating the battery as a preventative measure in some circumstances.

 

[MSvirus]

In my car, the central screen has a popup with a question about putting intelligent battery heating on, when the outside temp drops down to -10C. At -9 my car hasn't asked about it. So that is probably MGs programmed low level for IBH, that would mean they consider it to be useful then.

 

[Rolfe]

Some time ago many of us in more temperate climes were getting that pop-up when the ambient temperature was warm. I got it at 17°C once. At which point I told it not to show that message again. Which may have been a mistake, for winter.

I did notice a very slight power limitation when trying to take a fairly steep hill fast, at under 20% SoC and in cold (<5°C) temperatures. But it was very subtle.

 

[tsedge]

X-power drivers have experienced power limits when the battery is cold.
I’ve never experienced power limits myself and I don’t think most people will have noticed even if they had.
But then a year old battery is relatively new, with a high state of health and low degradation.
I think generally speaking the benefits of battery heating is mostly noticed when charging.
Yet I think it’s worth considering heating the battery as a preventative measure in some circumstances.

Yes, it does happen with the XPower but that's more understandable because the battery pack is under far more stress due to the twin motor demand, so will only be able to give its best under ideal circumstances.

I was talking about the LR vs SR specifically, LFP is known to struggle more with low temperatures, but it could just be the maturity of the management software.

I am just trying to understand if there's a difference here or not, since people are reporting something I don't see. Maybe it is because it is rarely very cold here?

 

[Rolfe]

I think that's likely. I only noticed a very slight loss of power when there was a combination of cold temperature and low SoC.

 

[siteguru]

Adaptive regen is also worth a try, it has less regen at high speed and is my preferred mode.

Adaptive is certainly worth trying, but my experience (in my SE SR anyway) is that it still applies a higher level of regen when "coasting" than does Regen 1.

A = 8% (from memory)
1 = 5%

The difference seems small but is noticeable.

 

[fnegroni]

I only use regen A on long journeys because after a while my right foot gets tired.
Regen 2 when it’s a bit slippery

 

[lsb777]

Thankyou, all great information!! What’s the best mode to drive in? I’m presuming eco?

Usually yes ECO is best for efficiency. I drove from Brighton area to Liverpool & back last weekend in Xpower using ECO and averaged 3.0mls/kWh for the almost 600 mile trip with a bit of HVAC when needed to clear the windows.