I don't know any details on what the buffers are on the MG ZS SR but they would have to have a bottom buffer for sure. Speaking to Miles Roberts of the Chorley Group earlier this week after the Podcast he said that even though the ZS LR has LFP the Charging menus on the SR are the same as LR so there is still an 80% indicator on the screen although he didn't think it did very much since the car should be charged to 100%. there needs to be much more education about this. Tesla is the other mainstream EV company with lots of LFP cars coming into customers' hands and I believe they make it clear initially or the recommended daily charging level. I think people who have driven EVs for some time will find it instinctively wrong to charge to 100% all the time but we all need a little more transparency about what the battery needs to get the best out of it. Cross fueling Diesel in a Petrol car or vice versa is the ICE equivalent although it has a more immediate effect. If you put a little Petrol in a Diesel car's tank providing it's not empty of diesel you can probably get away with it at first, but it will have accelerated engine wear and damaged the fuel pump although the car will run. Charging in an inappropriate way at first you'll probably not notice but at some point, the range will suffer because the battery will not accept as much charge.Yes - that makes sense. Do you know if LFP packs have a top and bottom buffer? Is the usable capacity improved from li-ion?
It is patchy but were are hoping to address this on an upcoming Podcast possibly along with home storage batteries.If there are optimum ways to keep the batteries in tip top condition depending on the battery, are the manufactures guiding the owners with this information ?
Great, I'm glad you're happy with the way your charging routine is working for you. However, remember that there is a top buffer on your battery pack so that when you see 100% that is 100% not of what your battery pack could physically charge to but 100% of the usable battery. This buffer is there because every cell in the pack is slightly different and therefore if your car's BMS just let you keep charging until it could physically take no more the cells the first cells to reach their maximum would fry as you kept pumping power in which they couldn't accept. Also, it is a physical fact that cells degrade through a number of factors including age/time, charge cycles, State of Charge and temperature. Therefore, your battery cells will have degraded in a year, 9000 miles and charging to 100% it is just that the degradation may have been minimal if, for example, you didn't leave your car with 100% charge without driving it soon after.I typically charge my car to 100%. After a year and 9000 miles at the annual service the car was reported as showing zero degradation so I don't think charging to 100% is having a significant impact on the battery.
Surely it's in all the manufacturers interests to advise people the best way to charge their cars to maintain the batteries, if it makes a recognisable difference, much as they would tell you what oil to put in your engine, and what servicing it needs, (or what fuel to put in). If it is understood, surely they should pass this on clearly and unambiguously, and people shouldn't have to seek out this information or interpret voltage charts.It is patchy but were are hoping to address this on an upcoming Podcast possibly along with home storage batteries.
Certainly it's your last point. Any admission that the batteries require some kind of thoughtful protection would add to the narrative that batteries will die and need replacing. They're confident that whatever you do will be within the tolerance of the warranty so they simply don't need to worry people.Surely it's in all the manufacturers interests to advise people the best way to charge their cars to maintain the batteries, if it makes a recognisable difference, much as they would tell you what oil to put in your engine, and what servicing it needs, (or what fuel to put in). If it is understood, surely they should pass this on clearly and unambiguously, and people shouldn't have to seek out this information or interpret voltage charts.
Or perhaps the fear is that guidance could be seen as 'restrictions' on charging and another layer of complexity, and reduce EV take up ?
Spot on. The top buffer hids the initial degradation and this was something that Nissan failed to do with the early LEAF. They were keen to have a high (for the time and available tech) capacity and so there was very little top buffer and their "Guaranty" was that the battery would have 70-% of the capacity new after the 8 years (if I recall) use. they offered a battery replacement in the event of it failing. Later models, Nissan seemed to have learned the lesson a little although last time I checked they were still inclined to publish a higher battery than the actual User Available capacity to the user whereas other makers tend to publish the useable capacity. I use "EV Watchdog" App with an OBD2 Dongle on my ZS and it shows on the SOC screen both the SOC % of the actual capacity and SOC % usable capacity. Therefore I can see a 100% useable SOC, but also the lower SOC % of the actual Battery.Certainly it's your last point. Any admission that the batteries require some kind of thoughtful protection would add to the narrative that batteries will die and need replacing. They're confident that whatever you do will be within the tolerance of the warranty so they simply don't need to worry people.
The objective truth is that you can't avoid battery degradation - it is inevitable - but you can mitigate it. However, it's generally too complicated to explain the nuances to your average end user so they keep the advice simple and not too scary. Some manufacturers build in a big buffer which (contrary to popular opinion) doesn't prevent all degradation but certainly reduces it significantly and (probably more significantly) provides a place to hide the initial degradation. That's how they're able to confidently tell you that your battery still has 100% state of health, even though it's a widely known fact that batteries degrade more in the first year than at any other time.
So how much degradation has there been with the "actual battery" ?Therefore I can see a 100% useable SOC, but also the lower SOC % of the actual Battery.
There is actually a State of Health (SOH) on one of the screens which tells me:-So how much degradation has there been with the "actual battery" ?
Hi Alb, I've had my car for about 8months and 8600 kms and always use the granny cable to charge. I usually charge 2 times per week going up to 100% and down to roughly 30%.Had the car for a month now and I don't think the state of charge has ever dropped below 80%.
I'm not doing any long journeys so do you think it would be better for the battery if I ran it down and maintained it a much lower state of charge?
I'm only using the Granny at the moment so charging rate has only ever been low.
Oh this is hurting my head, I can't granny or home charge so use public rapid and fast chargers. Had the car since March and never balanced charged in 3000 miles covered. Hmm, wonders if this is doing the batteries in. ?Very informative - thank you. Do you know why they should be charged to 100%? I guess in a none technical sense i’ve aleays thought a fully charged pack puts stress on the cells and should not be left for a long time in this state - how is this not the case with LFP do you know? ? So I guess it’s ok to leave your car fully charged for a long time with LFP?
Fast charging is AC? So you’ve likely got a type 2 cable? Easiest way is to DC rapid to 90% or so and then pop on a public AC type 2. The last 10% / 5.7kWh will take a little under an hour. Then leave it on for another couple of hours whilst shopping, cinema, walking home, etc? Should be enough to balance. Maybe?Oh this is hurting my head, I can't granny or home charge so use public rapid and fast chargers. Had the car since March and never balanced charged in 3000 miles covered. Hmm, wonders if this is doing the batteries in. ?
Cheers, will stick it on an AC charge down at my localish charging station and leave it on all day, that should do it ? or as you say dc charge it if the dc is available then balance. ??Fast charging is AC? So you’ve likely got a type 2 cable? Easiest way is to DC rapid to 90% or so and then pop on a public AC type 2. The last 10% / 5.7kWh will take a little under an hour. Then leave it on for another couple of hours whilst shopping, cinema, walking home, etc? Should be enough to balance. Maybe?
Alternatively, balancing takes very little power so could be done via granny charger at an accommodating friend/relative/unsuspecting neighbour with an unsecured outside socket!!
Think you got me wrong, dc up to 80ish percent then on to ac to balance. ?You cannot balance on DC and I wouldn't go over 90% on a rapid.
Each type of chemistry has its prefered stable state. With LFP cells typically use Graphite Anode material and Lithium (Li) Iron (Fe) Phosphate (PO) material Cathode are chemically stable at 100% charge when as I understand it the Lithium "ions" produce stable bonds and therefore they are safer and less stressed than many other Lithium-based battery chemistries.Very informative - thank you. Do you know why they should be charged to 100%? I guess in a none technical sense i’ve aleays thought a fully charged pack puts stress on the cells and should not be left for a long time in this state - how is this not the case with LFP do you know? ? So I guess it’s ok to leave your car fully charged for a long time with LFP?
yes all pre FL.When do you know that the equalisation process has finished on the MG5 SR?
I read this earlier:- "Anyways, you know this has occurred when you give enough time for 100% charge on either granny or 7kW AC charger and the status on the info screen says (IIRC) "100% SOC, Charger Connected, Uncharged".
Is this on the MG5 SR?