MG4 First EV & Advice

[DylanHalliday]

Hi All,

First of all very odd to be posting unexpectedly in the MG4 thread today. As a bit of background I have been kicking around these forums since ordering my MK2 ZS EV Trophy (silver). That still hasn’t arrived since ordering end of feb / start of March with people from November last year still waiting. We were looking for a second electric car anyways and with the release of the MG4 which fit right into our budget with tech vs cost compared to the likes of the ID3 & Cupra range. So we went ahed and got a stock dealer black SE SR MG4 available next week. Now we did want the SE LR or the trophy LR however these seem a rarity at the moment (see other threads) and as a side note if anyone knows of any dealers with stock available for these can they let me know.

Now our logic on the short range was that it’s a second car and less journeys will be spent doing the longer road trips, we would like the tech touches such as heated seats and steering wheel for the chilly Scottish weather which should have been better than using the VAC system for efficiency etc I was also informed that the SR cars actually use different battery technology LFP which means preferred charging between 0 & 100% which actually could work out better. The tech in the LR for battery health mode prefers 20-80% charging therefore essentially reducing the range to in the same figures as the SR. If someone could let me know what I need to consider for this new battery tech that would be super as we have been doing our research all based on our ZS EV LR order this is all very new.

This might be a great place for all new MG4 owners to share their experiences & knowledge too! I’ll definitely keep you all updated & definitely and obligatory flap photo on arrival . Also keep your fingers crossed that the MG gods will eventually deliver the ZS.

 

[the briggie]

Research shows 20 -80% is the sweet spot for battery health and longevity. Most manufacturers will tell you to use 90% as the recommended upper charge level to maintain battery health and avoid below 10% if possible. All EV's have an upper and lower buffer charge level. First example my current car is 35.5KW but only 30.5kw is usable under normal conditions, the upper buffer to stop overcharging and the lower buffer as a get you home emergency few kw. It is never recommended to take it down to 0%. Regular 90% with 100% for planned longer journeys is how I do it. Regular DC fast charging can also affect battery health so only use when necessary. It's all down to how individual owners want to use the car in the end.

Electric car battery life: how to preserve your battery | DrivingElectric

Here's how to preserve your electric car’s battery life and how much a replacement will cost if you need one

www.drivingelectric.com

Alan

 

[DylanHalliday]

Research shows 20 -80% is the sweet spot for battery health and longevity. Most manufacturers will tell you to use 90% as the recommended upper charge level to maintain battery health and avoid below 10% if possible. All EV's have an upper and lower buffer charge level. First example my current car is 35.5KW but only 30.5kw is usable under normal conditions, the upper buffer to stop overcharging and the lower buffer as a get you home emergency few kw. It is never recommended to take it down to 0%. Regular 90% with 100% for planned longer journeys is how I do it. Regular DC fast charging can also affect battery health so only use when necessary. It's all down to how individual owners want to use the car in the end.

Electric car battery life: how to preserve your battery | DrivingElectric

Here's how to preserve your electric car’s battery life and how much a replacement will cost if you need one

www.drivingelectric.com

Alan

Thanks for the advice Alan! Throw all that new EV ownership advice my way!

 

[CSL]

The recommended charge level for an LFP is 100% at least once a week. LFP is the battery in the standard range and coincidently used in the standard range of the Tesla - both 3 and Y. LFP is a safer chemistry than Lithium Ion based batteries (used in the Long Range versions) and it is not recommended to charge these (routinely) more than 80% charge. 100% only occasionally for longer journeys is of course fine.

The LFP is a little more tolerable of colder conditions - great for UK winters. It is generally only used in the smaller standard range form - as the batteries are actually a little heavier than Lithium Ion - therefore the batteries are smaller to balance the weight and can hold less charge.

You will note there is little difference between the kerb weight of the MG4 SE SR v LR.

The only drawback (with charging everyday to 100% (which these batteries like)) - is that regen will be reduced until you have driven for a while and the % charge reduced - be conscious of this in the MG4 - as you will need to use the brake peddle a little more than expected if using the hard regen setting as your routine - when you first set off. I am sure we will get used to it.

As mentioned LFP is a safer chemistry - LFP cannot catch fire - we have LFP Sonnen home batteries for this very reason - and this is also the reason Tesla’s Power Wall home batteries have to be installed outside the main house - as they are Lithium Ion based (which is why we did not go for them).

Of course the fire risk is extremely low on Lithium Ion and every safety measure will have been deployed to ensure this - but there is a very small risk if the battery is ever punctured (in an accident for example) - in the very very rare event fire does take hold - once it has its is very hard to put out.

With LFP nothing will happen.

I was lucky enough to have owned a standard range Model 3 for awhile - absolutely no difference in performance compared to the LR versions (I also had one of those Model Y) - range is a little less of course - but as a man of a certain age - there was no way I could drive and use all the range the standard range offers - without needing a rest stop - and planning my journey accordingly.

Charger availabilty is more of a concern these days - in my personal opinion - rather than range anxiety - although even that is getting better.

My new MG4 SE SR (Red) - when I get it - will be my fourth BEV - and I am really looking forward to it.

I hope you enjoy yours too.

 

[the briggie]

Every day is a school day when you get your first ev. From home charging, granny or 7kw to AC 11kw chargers to DC fast chargers...and getting apps and cards to access public charging. Retraining your right foot and removing the divers boots. The setting menu alone is an never ending voyage of discovery...enjoy when you get it

Alan

 

[the briggie]

I read this re LFP hence the confusion re Tesla and LFP

Best charging behavior for LFP batteries​

BY PEDRO LIMA · PUBLISHED 21/04/2022 · UPDATED 27/04/2022


I have been writing about the importance of LFP (LiFePO4) batteries for a while now, but I haven’t written about the best charging behavior for this battery chemistry yet.
It’s time to write a small, but important article about the subject, especially because I have seen some confusion on online forums.

Extract as follows;

Therefore, it’s obvious that keeping the batteries at lower SoC (State of Charge) is better for their cycle life.

Now let’s talk about the confusion generated by a recommendation from Tesla…

If your vehicle is equipped with an LFP Battery, Tesla recommends that you keep your charge limit set to 100%, even for daily use, and that you also fully charge to 100% at least once per week. If Model 3 has been parked for longer than a week, Tesla recommends driving as you normally would and charge to 100% at your earliest convenience.
Following the above guidance maximizes available range and improves the vehicle’s ability to accurately determine the state of charge and estimated range.
Tesla

Does it mean that LFP batteries are immune to extra battery degradation associated with frequent full charges? No…

The only reason why Tesla recommends to fully charge the Model 3 cars that have LFP batteries is because it helps the BMS (Battery Management System) to estimate the available battery capacity more precisely.

 

[DylanHalliday]

Top level advice all - much appreciated!

 

[DylanHalliday]

The recommended charge level for an LFP is 100% at least once a week. LFP is the battery in the standard range and coincidently used in the standard range of the Tesla - both 3 and Y. LFP is a safer chemistry than Lithium Ion based batteries (used in the Long Range versions) and it is not recommended to charge these (routinely) more than 80% charge. 100% only occasionally for longer journeys is of course fine.

The LFP is a little more tolerable of colder conditions - great for UK winters. It is generally only used in the smaller standard range form - as the batteries are actually a little heavier than Lithium Ion - therefore the batteries are smaller to balance the weight and can hold less charge.

You will note there is little difference between the kerb weight of the MG4 SE SR v LR.

The only drawback (with charging everyday to 100% (which these batteries like)) - is that regen will be reduced until you have driven for a while and the % charge reduced - be conscious of this in the MG4 - as you will need to use the brake peddle a little more than expected if using the hard regen setting as your routine - when you first set off. I am sure we will get used to it.

As mentioned LFP is a safer chemistry - LFP cannot catch fire - we have LFP Sonnen home batteries for this very reason - and this is also the reason Tesla’s Power Wall home batteries have to be installed outside the main house - as they are Lithium Ion based (which is why we did not go for them).

Of course the fire risk is extremely low on Lithium Ion and every safety measure will have been deployed to ensure this - but there is a very small risk if the battery is ever punctured (in an accident for example) - in the very very rare event fire does take hold - once it has its is very hard to put out.

With LFP nothing will happen.

I was lucky enough to have owned a standard range Model 3 for awhile - absolutely no difference in performance compared to the LR versions (I also had one of those Model Y) - range is a little less of course - but as a man of a certain age - there was no way I could drive and use all the range the standard range offers - without needing a rest stop - and planning my journey accordingly.

Charger availabilty is more of a concern these days - in my personal opinion - rather than range anxiety - although even that is getting better.

My new MG4 SE SR (Red) - when I get it - will be my fourth BEV - and I am really looking forward to it.

I hope you enjoy yours too.

You may have already answered this so sorry in advance. With LFP batteries enjoying more deep cycle charging does this mean from 0-100% recommended once a week I.e fully discharge the battery and then to 100%? I’m new to all of this but trying to strike the balance between SOH of the battery & actually not thinking too much about things.

 

[the briggie]

No. See my post above. Lithium batteries, no matter the composition, do not like a 0 to 100% cycle. LFP do not need a deep cycle once a week. 100% daily is a Tesla thing purely for that cars BMS not the battery health. As stated it is not recommended to take LFP down to 0%. 20 to 80% is best, 10% ok. The BMS (battery management system) will balance the cells accordingly.

Also think of the practicalities. Are you going to throw away good energy to get to 0%. Drive round and round the block perhaps. Sit with the heating full blast for hours? Ensure 0% comes right when you are next to a charger?

Se sr will take about 20+ hours on a granny plug,, 7+ hours on a home charger, 4.5 plus at a public ac charger and dc charge ? depending on the kw rate...

Please, don't do it

Alan

 

[DylanHalliday]

No. See my post above. Lithium batteries, no matter the composition, do not like a 0 to 100% cycle. LFP do not need a deep cycle once a week. That is a Tesla thing purely for that cars BMS not the battery health. As stated it is not recommended to take LFP down to 0%. 20 to 80% is best, 10% ok. The BMS (battery management system) will balance the cells accordingly.

Also think of the practicalities. Are you going to throw away good energy to get to 0%. Drive round and round the block perhaps. Sit with the heating full blast for hours? Ensure 0% comes right when you are next to a charger?

Se sr will take about 20+ hours on a granny plug,, 7+ hours on a home charger, 4.5 plus at a public ac charger and dc charge ? depending on the kw rate...

Please, don't do it

Alan

this makes sense to me actually - I was thinking the same, to physically get to 0 would be unpractical for any healthy way of driving. Stats seem pretty good for charging and in line with competitors - going with octopus energy so should be good.

 

[the briggie]

Go to 100% once a week by all means but no need for total recycle. I go to 90 most days and 100 every second week for a longer journey.

Octopus are really good. Up here it's about 2 - 3 weeks for a Smart meter installation. I use Octopus GO rate as I have a Shell recharge home charger. Most of my charging is Tesco, Sainsbury's which round here are free, and locally I have a free Chargeplace Scotland charger as well.. My last three months have cost me 45p thanks to this. Hope your charger installation goes fine...won't tell you about my 18 month nightmare

Alan

 

[loydex]

Go to 100% once a week by all means but no need for total recycle. I go to 90 most days and 100 every second week for a longer journey.

Dear Alan, would you recommend the same approach when it comes to charging the Trophy? Predominantly on type2 home charger. Apologies if I missed your suggestion.

 

[the briggie]

Yes. LFP batteries on standard range are more rebust but have less energy density. The SR LR and Trophy use Lithium ION technology. Both technologies need battery management for health and longevity. If you are mostly doing short journeys keep it between 20 to 80% if possible. Most of us don't need to use full range charge for our daily use but the temptation is to keep it full at all times. Been there got the T shirt. How often do/did you fill your fuel tank on an ICE car...so follow the same basic principle. I go for 90% as an upper for my standard use and go to 100% when I know I have a longer journey. In my case every 2 weeks. Only use DC charging when absolutely necessary. Faster high kw charging creates higher battery temperatures which over time reduce battery health if used too frequently. Home 7kw or public 11kw are less stressful assuming you don't go 100% every day.

At the end of the day it's up to individual owners how they want to do it. Lease cars..nah...only holding on for a couple of years PCP or otherwise...nah..
care about longevity and next owner etc. yeh

Alan

 

[loydex]

Great response! Appreciate your time and effort writing this.

 

[the briggie]

Also be aware. Car regeneration will not be effective at 100% so you are wasting regenerated energy opportunities. My car starts to have more effective regen around the 90% mark. The regen adds to the efficiency and range calculations done by the bms. Think of it as a full glass and you are trying to add extra liquid. The glass wont accept it and the liquid is wasted. Same with regen, the batteries will not accept top up as they are full so the energy is wasted.

Alan

 

[Whiskey Foxtrot]

Also be aware. Car regeneration will not be effective at 100% so you are wasting regenerated energy opportunities. My car starts to have more effective regen around the 90% mark. The regen adds to the efficiency and range calculations done by the bms. Think of it as a full glass and you are trying to add extra liquid. The glass wont accept it and the liquid is wasted. Same with regen, the batteries will not accept top up as they are full so the energy is wasted.

Alan

Understood, so why not set regen at 0 and coast using momentum for the first 10% of battery from full, therefore no waste?

 

[MoDolph]

Starting with 100% is the only time my brakes get any use so it's useful to stop them rusting

 

[the briggie]

Agreed re setting to 0 regen if you do it on the steering wheel. Not recommended to do it in settings on screen whilst driving. The point I was trying to make is sitting at 100% when you don't need the range makes no sense. My car gives me an extra 15 miles of estimated range if I stay below 90% most of the time and then go 100% rather than 100% every day due to more effective regen. 100 to 90 you lose the regen opportunity so why set it to 0 if you don't need to be at 100% in the first place. I learned this through experience of my soon to be gone MX30.

As for the brakes just touch them occasionally with your foot. Helps stave of lazy leg syndrome

All up for debate just my rant

Alan

 

[JimB]

I have no idea how coasting is achieved in a pure ev but my Outlander phev actually uses power in regen 0 (of 5 settings) because the transmission is always live (I've never tried selecting neutral when the car's in motion, for reasons unknown) and the car uses drive power to overcome the drag in the transmission system.

When I first got mine I spent a lot of time on a forum where some Dutch enthusiasts seemed to never go anywhere without analytical gear plugged into the car, and that's where that came from.

 

[the briggie]

In my current EV if I have enough momentum and set minimum regen the power indicator normally sits between power draw and regen when "coasting on level roads most of the time. This indicates to me that although not generating it is creating minimum electric motor resistance. That is purely on the dial but in reality who knows what if anything the motor resistance contributes or not? Expert opinion welcome!!

Alan