[Jim R]

Thought about putting this in the 'General charging discussion'. As my question covers MG ZS both Mk 1 and 2 I have put it here. Mods, if that is wrong, sorry!

Reading an article on Money saving expert about EV's.Section 2 states that 'most manufacturers recommended you don't charge the vehicle to more than 80% of its total capacity in order to maintain your battery's capacity.'. Do people know if this applies to MG ZS? I have never been told or heard not to. And after the BMS issue of over a year ago, you needed to 'balance' the batteries and therefore had to charge to 100%.

I have had a ZS for nearly two and a half years and always charge at home to 100%. I have a ZS Mk 2 Long Range on order. Is it alright to charge this one to 100%?

 

[DSLRed]

The key principle I have always believed to be good practise is that, if you need to go to 100 because you are about to do a long trip that needs the range, then go for it. But don't leave it sat at 100 for any length of time - that's the killer.

If you are not expecting to burn the range off in a long trip, it is more gentle on the battery to stick to 80 or thereabouts.

The advice is different for LFP batteries where they have no issue wiith charging to 100 affecting long term health of the battery. In fact, it is positivity encouraged for that chemistry.

I am working at home most days and do most of my mileage gadding about at the weekend. I try to ensure that the car spends the week on the drive with the battery sat somewhere around the 50-60% mark if I can. Then charge it up to around 85% for the weekend, unless we are heading further afield, when I will charge to 100. I try to ensure it it charged to 100 around once a month on average to balance the cells but am not anal about the timing.

 

[Jim R]

Thanks fr the reply.

Do you know the type of battery in the MG, Mk1 and Mk 2 LR?

 

[DSLRed]

Thanks fr the reply.

Do you know the type of battery in the MG, Mk1 and Mk 2 LR?

So, I did a little search and I believe it is LI-ion NMC but it is not totally clear. I don't think that, other than Tesla, there are too many LFP out there right now. Hyundai / Kia are looking to use them on future more compact cars like the EV4 / Ioniq 3.

Have a look through this thread
'Facelift ZS EV LR battery type.' Facelift ZS EV LR battery type.

 

[Gadget Geek]

Short range - charge to 100%.
Long range - charge to 80%.

The car has a battery management system (BMS) which will look after the battery and the battery has buffers which means you will never drain it to 0% (which will kill the battery), nor fill it to actual 100%. So even abusing the battery will take years for any serious degredation to become apparent.

The battery killer in all EV's is multiple deep discharge - recharge cycles, i.e, 5% to 100% on a regular basis. Bjorn Nyland on TeslaBjorn on Youtube has done some good tests on battery longevity over the years. Always good for reference.

 

[Jim R]

Short range - charge to 100%.
Long range - charge to 80%.

The car has a battery management system (BMS) which will look after the battery and the battery has buffers which means you will never drain it to 0% (which will kill the battery), nor fill it to actual 100%. So even abusing the battery will take years for any serious degredation to become apparent.

The battery killer in all EV's is multiple deep discharge - recharge cycles, i.e, 5% to 100% on a regular basis. Bjorn Nyland on TeslaBjorn on Youtube has done some good tests on battery longevity over the years. Always good for reference.

Thanks @Gadget Geek. Mk 1 reasonable OK to 100%?

Very rare for me to have a car below 5%

 

[CampGareth]

The advice is different for LFP batteries where they have no issue wiith charging to 100 affecting long term health of the battery. In fact, it is positivity encouraged for that chemistry.

There's still a lifespan benefit to not charging fully but iirc the charge to 100% rule for LFP is about calibration. NMC and LFP have different voltage curves so you can tell SoC by voltage for NMC but have to count amp-hours in and out for LFP as it's a lot flatter. Over time your estimation of SoC from amp-hours count becomes inaccurate so charging to 100% where the voltage actually rises corrects your estimate. That's why some LFP Teslas that never reached 100% were in the news a while back for suddenly dying with 20 miles on the range estimate.

 

[dragon2611]

For the Ioniq I frequently only bother charging it to around 80% unless taking it on a long journey or it's been a long time since I last charged it to 100% as otherwise it will probably sit with a high SOC for several days. This is likely going back soon but i'd still like to look after the battery.

For the Leaf I'll probably charge it to 100% far more often because the thing has less range to begin with (30kwh leaf). Even then i'll not fully charge it unless I expect to drive it the next day.

I've noticed the current draw for the leaf is all over the shop for the last couple % of battery, it will fluctuate by 500w-1KW from one minute to the next.

 

[Paul_Moxhay]

I can't give a definitive answer... I am not an expert on battery tech. But I think it fair to say that there is still a lot of mixed opinions on the 80% vs 100% charging argument so I look at it like this...

As I am still unclear whether charging to 100% regularly is likely to affect the degradation of my battery I work on the principle that I will charge to 80% day to day and charge to 100% when I need to. I never avoid charging to 100% if I need the range... that is what the car is for - to be used. But I cannot see any benefit in taking any unnecessary risks by charging to 100% if I don't need to. It may well turn out that I could have charged to 100% all the time without concern but as I didn't need that extra 20% in the first place then I haven't actually lost out on anything have I?

So my recommendation to all EV owners is, if you are unsure, charge to 100% if you need to but only to 80% if you don't. This is a "just to be on the safe side" approach but doing that will do no harm.

Of course, the caveat of always follow the manufacture's advice applies - (RTFM!), and that includes a 100% charge now and then to balance the cells if the manual says so

 

[Gadget Geek]

As I am still unclear whether charging to 100% regularly is likely to affect the degradation of my battery I work on the principle that I will charge to 80% day to day and charge to 100% when I need to. I never avoid charging to 100% if I need the range... that is what the car is for - to be used. But I cannot see any benefit in taking any unnecessary risks by charging to 100% if I don't need to. It may well turn out that I could have charged to 100% all the time without concern but as I didn't need that extra 20% in the first place then I haven't actually lost out on anything have I?

When I used to drive an ICE car, I never filled the tank unless I was going on a long journey, it's just excess weight reducing your MPG. I only ever fill my battery if I'm going on a long journey or I want to balance the cells. If the battery is happiest within the bell curve of 20% to 80%, I see no reason not to keep it there.

 

[freddym]

I can't give a definitive answer... I am not an expert on battery tech. But I think it fair to say that there is still a lot of mixed opinions on the 80% vs 100% charging argument so I look at it like this...

As I am still unclear whether charging to 100% regularly is likely to affect the degradation of my battery I work on the principle that I will charge to 80% day to day and charge to 100% when I need to. I never avoid charging to 100% if I need the range... that is what the car is for - to be used. But I cannot see any benefit in taking any unnecessary risks by charging to 100% if I don't need to. It may well turn out that I could have charged to 100% all the time without concern but as I didn't need that extra 20% in the first place then I haven't actually lost out on anything have I?

So my recommendation to all EV owners is, if you are unsure, charge to 100% if you need to but only to 80% if you don't. This is a "just to be on the safe side" approach but doing that will do no harm.

Of course, the caveat of always follow the manufacture's advice applies - (RTFM!), and that includes a 100% charge now and then to balance the cells if the manual says so

You start by saying you are not an expert and then you say my advice to ALL ev owners is to...

My advice would be to keep your advice to yourself.

 

[Paul_Moxhay]

You start by saying you are not an expert and then you say my advice to ALL ev owners is to...

My advice would be to keep your advice to yourself.

I am no expert on batteries but I am a very experienced EV owner so while I cannot give specific advice about the internal workings of batteries I am very able to offer valuable and sensible advice to people on how to use them.

Why can't you be a nice person and not have a go at people like that unnecessarily?

 

[donald]

Thought about putting this in the 'General charging discussion'. As my question covers MG ZS both Mk 1 and 2 I have put it here. Mods, if that is wrong, sorry!

Reading an article on Money saving expert about EV's.Section 2 states that 'most manufacturers recommended you don't charge the vehicle to more than 80% of its total capacity in order to maintain your battery's capacity.'. Do people know if this applies to MG ZS? I have never been told or heard not to. And after the BMS issue of over a year ago, you needed to 'balance' the batteries and therefore had to charge to 100%.

I have had a ZS for nearly two and a half years and always charge at home to 100%. I have a ZS Mk 2 Long Range on order. Is it alright to charge this one to 100%?

For any sort of 'dwell' where the battery is not in use (be it overnight, or for months) the closer you can keep your battery to 50% the better.

80% was the practical limit to that advice with 22kWh batteries.

Now with relatively huge batteries, a typical user might well be able to shuffle between 40 and 60%, covering say 30 to 50 miles a day and charging up for just a couple of hours overnight at 7kW every night.

Whether you can be bothered with that faff, if you do 30 miles a day, or just want to charge up to 100% on Monday morning and not bother again until next weekend, well, that is up to you, but charging a little and very often, staying around 50% as best you can, is always going to mean the battery lasts as long as it is likely to last.

 

[DSLRed]

My advice would be to keep your advice to yourself.

Unnecessary.

This is a forum. People post advice. It's what they are for.

 

[donald]

Irony, missed .... @DSLRed , I think they both know that but there is some history of wind-up and easily wound-up-ness. Best leave it.

Meanwhile, I am an expert on batteries {i have 'professional experience'!] and @Paul_Moxhay's general advice to all is sound in this particular example, what he does is perfectly fine, and in fact pretty much anything one does will be perfectly fine but just avoid leaving a Li-ion battery a while with high or low SOC.

 

[Jeremy Harris]

The bottom line is just follow the manufacturers instructions. They own the warranty on the battery, have designed the BMS to protect the battery pack and there is absolutely no way they are going to offer that warranty unless they are confident that their instructions are clear and effective. With the sole exception of Tesla, AFAIK, 100% indicated is not actually 100%. The majority of EVs have a buffer, usually around 5%, and during the 20 years or so I've been building battery packs I can say with certainty that a 5% buffer is more than enough to prevent excessive cycle life degradation. Add in that EV batteries just don't get cycled much in their lifetime anyway, and I remain absolutely convinced that there is a massive amount of myth and bullshit being spread around about what owners need to do.

Best advice is just read the manual, follow its instructions and ignore all the crap that's spouted on social media . . .

 

[freddym]

The bottom line is just follow the manufacturers instructions. They own the warranty on the battery, have designed the BMS to protect the battery pack and there is absolutely no way they are going to offer that warranty unless they are confident that their instructions are clear and effective. With the sole exception of Tesla, AFAIK, 100% indicated is not actually 100%. The majority of EVs have a buffer, usually around 5%, and during the 20 years or so I've been building battery packs I can say with certainty that a 5% buffer is more than enough to prevent excessive cycle life degradation. Add in that EV batteries just don't get cycled much in their lifetime anyway, and I remain absolutely convinced that there is a massive amount of myth and bullshit being spread around about what owners need to do.

Best advice is just read the manual, follow its instructions and ignore all the crap that's spouted on social media . . .

Agreed.

 

[Gadget Geek]

Best advice is just read the manual, follow its instructions and ignore all the crap that's spouted on social media . . .

Or anything Jeremy Clarkson says.

 

[Paul_Moxhay]

You are digging the same hole deeper. What makes you think your advice is either sensible or valuable. All you are offering is platidudes based on " what you overheard in the pub". Totally worthless.

You are not only rude but wrong... Best stop digging imo.

How about taking some classes in being friendly... you certainly need them.

 

[Paul_Moxhay]

The bottom line is just follow the manufacturers instructions. They own the warranty on the battery, have designed the BMS to protect the battery pack and there is absolutely no way they are going to offer that warranty unless they are confident that their instructions are clear and effective. With the sole exception of Tesla, AFAIK, 100% indicated is not actually 100%. The majority of EVs have a buffer, usually around 5%, and during the 20 years or so I've been building battery packs I can say with certainty that a 5% buffer is more than enough to prevent excessive cycle life degradation. Add in that EV batteries just don't get cycled much in their lifetime anyway, and I remain absolutely convinced that there is a massive amount of myth and bullshit being spread around about what owners need to do.

Best advice is just read the manual, follow its instructions and ignore all the crap that's spouted on social media . . .

Totally agree but people don't read the manual most of the time even though they should. My point is that my advice is not bad advice as a starting point regardless of what battery or car you have. There is no risk to charging to 80% ever... but, depending on your battery tech and how your BMS works, there might be a risk to charging regularly to 100%. So my advice works for everyone that doesn't read the manual or who has a car with a rubbish manual that doesn't specify that much detail.

You are digging the same hole deeper. What makes you think your advice is either sensible or valuable. All you are offering is platidudes based on " what you overheard in the pub". Totally worthless.

No platitudes here... just sound advice for anyone as a starting point. Of course, if your manual says something else then do that!

The problem here is that you just hate it when I am right and you will do anything to insult and discredit me. Unfortunately for you all you are doing is making yourself look like the complete ploker that you are. Now ignored (yes... another one ) so your future comments fall on deaf ears. Have a great day