Electric Car Batteries - Only Using 20% to 80%

Also this varies by battery type. the Tesla Model 3 owners manual states that "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." For me the cheap overnight 4 hours will add about 55% so I typically run it down to under 30% before plugging it in. When I know I'm going to do a long distance I will make sure I charge to 100%, it pointless to set off with only a partial charge.

I plug my car in to use the energy from my solar system. Today it has charged “gently” to 100%. By doing it this way the guessometer always gives me more available miles than even the overnight 7kw charge. It’s always been like this from new, now two years old and actual miles exceeds the manufacturer’s quote for the MG5 of 214 at this time of year! Similar results if using the granny charger. The battery seems to like gentle rather than being force fed! Keep up the great work!

I've flown model planes that use lipos for over 20 years and only really killed batteries at the start because, A, the batteries were not very good back then B, I didn't know how to use them and was leaving them fully charged all the time and flying them down to empty every time, this killed them in around 30 cycles. Once I understood the storage thing and not flying down to empty every time things improved a LOT and batteries also got better, now I have a ton of batteries that are very old and have many many cycles on them but are perfectly fine, I still occationally fly down to empty by mistake and sometimes charge fully thinking I'll go flying but dont end up going right away but as long as I'm not doing that every time its fine. I think dealers should get better education if they are dishing out stupid advice like they gave you, print out a card with how to use a battery and give it to every customer maybe an idea. You are exactly right in your approach, simple common sense...

A worthwhile video because it's something which I often see coming up on user forums. One thing though battery chemistry also matters and while with traditional Li-Ion 80% is a helpful discipline LFP is happy daily charging to 100%. Dealers as you rightly say ought to be better sources of good information. I have replied to many such questions asked by newbies to the EV world of motoring on the MGEV Forum for example and many people pile in with conviction on what you absolutely Must or Must-Not do, and while there is so much disinformation from the dealers, EV owners aren't getting the best experience from the cars they spent a lot of money on plus many others are being discouraged until they can buy a car with 500 or 600-mile range only using 80% down to 20% of their EV's battery. Early 44 kWh MG ZS EV didn't have any of battery percentage indication and my dealer told me I should just charge it to 100% every time and not worry because MG had taken care of all that with the battery buffer. This was not really true as proven but the 2nd Gen cars which did have battery percentage indication and the 64 kWh Li-Ion equipped cars had a screen similar to what you showed in your Tesla indicating 80% Daily and 100% Trip with the ability to set a charge limit. Then MG confused everyone when they introduced a 51kWh ZS equipped with LFP chemistry and the same 80% Daily / 100% trip screen however they disabled the facility to limit the charge because charging to 100% is preferred with an LFP as it improves the accuracy of the State of Charge (SOC) calibration of the Battery Management System (BMS). Advice for Tesla on LFP-equipped newer Standard Range is also to charge to 100%.

I love your no-nonsense videos and the knowledge and advice in them. Likewise, I got next no advice from the dealer who on handover was pretty clueless about setting everything up on my MG4. Just glad I’d spent the previous 6 months watching every YouTube video I could find about it.

Yet another sensible video from EVM. I've charged my MG5 to full a lot of times and for 4 hours cheap rate overnight. After 25k miles the range is exactly the same as when it was new 15 months ago

I bought an ioniq 38kw which states 193 miles on a full charge. As I am retired and do less than 150 miles a week this 20 to 80 suits me perfectly. If I go on an occasional longer trip I charge to 100% so I use as less public charging as possible. 11p per Kw at home is better than 79p per Kw on public chargers.

Thank you for this! I have a 2023 Crosstrek PHEV and I typically charge it to what looks like ~97%. I know that they have a buffer on the battery as well, so it is definitely less than what I think it is. I was looking for this type of information for a while actually. Thanks for sharing your knowledge.

Battery chemistry also matters. LFP batteries like to be charged to 100%, hence why they are in the smaller range models

Ah yes, the BS of the uninformed. We tend to keep our battery between 20% and 80% for normal use but I will happily bang in 100%, especially when charging on cheap juice overnight if we are going on a longer journey the next day. We've had it below 10% once as well. Shock, horror !!!

Thanks EVM, all grist to the mill. I've owned a Kia e-Niro from new since March 2019. The manual says that if you don't need to charge it to 100% for your use case then they recommend you doing that once a month. This is to give the BMS a chance to look at the max voltage levels across all the cells, there are 294 cells in the 64 kWh e-Niro. But of course the real size of the battery is 67.5 kWh so as the battery ages the BMS can detect a weak cell, drop it out of the available pack (64KWh) and increase the voltage slightly on the other 293 cells to maintain the useable battery. As EVM man says, the BMS maintains floor and ceiling buffers. The floor buffer is to make sure the cells never get to zero volts which would do big damage to the pack, the ceiling buffer allows the BMS to maintain the overall capacity of the pack. My use case is covered by plugging in once a week and charging to 80% but of course for a long trip I charge to 100% before leaving then do as you suggest, only charge to 80% on public rapid chargers en route, it just isn't worth hanging around to add more. When coming home from a long trip once I did get as low as 7% but when you get home you just plug in of course. There's a lot of talk about the relative merits of NMC and LFP in terms of battery longevity but for all practical purposes it doesn't matter. Even if I charged to 100% every time on my NMC pack and went <10% every time I would be able to do that 1,000 times before seeing serious range loss. So with a range of comfortably 250 miles that 250,000 miles! The main advantages with LFP is that they are cheaper and safer.

Really interesting ! Thanks !

This topic honestly comes up almost daily in the various FB EV groups I'm a member of, at least from new owners - it's astounding the level of mis-information that they leave their dealership with. So, yes - absolutely agree with you that dealer sales staff need to be MUCH better trained in their knowledge of EVs. One aspect of your video which might've been useful to have added, especially in light of the current state of the charging infrastructure network. Planning to stop at an on route public rapid charger at 20% battery level is probably quite sensible right now - that way, you'll at least have plenty of remaining mileage left in the battery for you to be able to drive away from the ever-increasing number of off-line / faulty / busy chargers to find one that actually works / is available...!!

The other factor in that is the fact that for most EV that's the SOC where the fastest charging lies. Added to that is that, for many its seen as very bad manners to go to 100% on public chargers as you are seen to be hogging the charger for a prolonged period because 100% is not seen as necessary for most trips.

Very well explained and good follow up video. I charge to 100% as and when required, which isn’t too often.

Good information mate

In 2019 I went to a Jaguar dealer to look at an I Pace. When I told him that three times a week I drove 250+ miles he told me that I was looking at the wrong type of car because the range of the I Pace was really only about 120 miles in “real world usage”. His reasoning was that due to the time taken to charge from 80 to 100% was so long that I would not want to wait around to charge to 100%. He also said that due to the unreliability of the UK charging network he didn’t recommend going below 20% unless I could guarantee a charge point that worked at in that last 20%. This gave me a useable range of 60% or 156 miles on the official test. Or as he put it, 120 miles in the real world. Needless to say I didn’t buy it.

I have a 2021 Tesla M3 SR+ the Tesla App states to charge once a week to 100% it's simple enough to follow the instructions (if the manufacturer supplies them) I use mine like a car, fuel as and when required + once per week charge to 100% - people do like to over complicate things or find another way to try and berate EV's and their owners or supporters. We can always rely on you to get the truth out their. Keep up the good work 🙂

Great video! We charged our 2023 Kona EV to 100% everytime we charged at home, DCFC not so much but that was just time management and charging to what we needed. We put 48,000 km on that car in 10 months and 0 noticeable battery capacity or range loss. We have now taken delivery of our Ioniq5 AWD Ultimate trim with 77kwh battery and treat it exactly the same. Likely looking at keeping this car for many, many years! No fear about capping at 80%, when charged to 100% the car does not sit, it gets driven....lots. Never go back to an ICE vehicle, still own a couple that rarely get driven anymore (except for our MGB & MGC) Mike

Well said! Maybe do a second video about how a battery pack consists of many cells that vary in voltage and that determines its percentage charge.