Battery charging beyond 80 percent

[Lobogris]

Most experts and publications recommended not charging the EV battery beyond 80%. They also advise keeping it between 30 to 80 percent as far as possible. Now since we know from OBD2 scans that the ZS has a built in buffer of around 7 to 8% and probably has a similar buffer on the low side, do we really need to impose an additional buffer on top of it? When the car shows 100%, it is only around 92 in reality. Should that much buffer not be sufficient? So can't we safely charge to 100% without worrying about battery degradation?

 

[Cocijo]

I haven’t read anywhere about recommending not charging beyond 80%. The packs are designed for this. I think you may have confused charging on a rapid past 80% where it generally slows down. It’s fine to fully charge your pack. The general advice is don’t leave it fully charged or discharged for long periods and if you don’t need to then running between around 30-80% charge is great. If you need to 100% charge and use - go ahead!

 

[Lovemyev]

I think most people who are charging via rapid units on a regular basis, are people who are generally in a hurry to be somewhere else as quickly as possible !.
Therefore they tend to stop the charge at around 80% ( ish ) because at this point the charge rate starts throttling back a LOT.
This is taking up valuable time they don’t appear to have, so they disconnect and continue with their hectic days work.
Clocking up more miles to the next charger.

 

[Lobogris]

I haven’t read anywhere about recommending not charging beyond 80%. The packs are designed for this. I think you may have confused charging on a rapid past 80% where it generally slows down. It’s fine to fully charge your pack. The general advice is don’t leave it fully charged or discharged for long periods and if you don’t need to then running between around 30-80% charge is great. If you need to 100% charge and use - go ahead!

See this:

You Should Set EV Charge Limit To Just 60 Percent: Here's Why

There is a whole lot of information and misinformation out there when it comes to EVs and charging. This makes it difficult for new electric car owners.

insideevs.com

 

[Lovemyev]

Tesla have started restricting the upper end speed after a large number of rapid charger cycles have been reached on their cars.
This to help with the longevity of the HV pack.
Bjorn Neyland had picked up on this last year, after speed reductions in charging at the higher end of the battery was noticed by him.
If anybody knows, he does !.

 

[Cocijo]

Interesting article. Thanks. I tend to keep my Tesla at around 75% charge - when I dont need the range which is most of the time. it has a 75kwhr pack which makes it easier to do. I charge my ZS to 100% most of the time but don’t leave it like that for long. I don’t agree with the suggestion of not charging to 100%. The article is not that well written in my opinion. My conclusion on consuming quite a few articles on this subject is as I previously mentioned. 100% is fine. Don’t leave fully charged or discharged for long. Excessive rapid charging should also be avoided if possible.

 

[Cocijo]

Tesla have started restricting the upper end speed after a large number of rapid charger cycles have been reached on their cars.
This to help with the longevity of the HV pack.
Bjorn Neyland had picked up on this last year, after speed reductions in charging at the higher end of the battery was noticed by him.
If anybody knows, he does !.

Yes, I’ve had experience of supercharger speed reduction on older tired battery packs. The supercharger network is so good many Tesla owners use it solely for charging (I used to) - some also get it free of charge. This eventually leads to a tired Duracell bunny.

 

[Dr Dave]

I only charge at 7kw, no fast chargers near me. I charge to 100% every time. What the point of an electric car if it is not full and ready should I need it for an emergency.

 

[Jomarkh]

I charge to 80-90% and once a month to 100% for the battery balance

 

[Kithmo]

I only charge at 7kw, no fast chargers near me. I charge to 100% every time. What the point of an electric car if it is not full and ready should I need it for an emergency.

Exactly, what's the point of only using 80% of the battery at the beginning of its life when you may only have 80% to use later down the line when the battery is older.
The charge to 80% philosophy means you have to buy a car with a battery that is 125% bigger than what you need so you can charge it to 80% of it's capacity for your needs.

 

[Headgas1]

First time I used a rapid charger it went from 21% to showing 100% on hv battery gauge in 45 mins which I couldn’t understand because everybody says it slows down massively at 80% yet mine didn’t seem to the only info I know is it delivered 31.2 kw in that time.

 

[Lovemyev]

To be honest, I think the jury will be out for a VERY long time on the debate on the whole subject of - "Should you charge to THIS level, or should you charge to THAT level".
A very controversial subject I know.
Impossible for there to be a right or wrong answer to THIS subject IMO.
I think the consensus of opinion is the same regarding the subject of, that regular and consistence rapid charging ( due to excessive heat ) is not good for EV pack's, plus fully charging to 100% then leaving the car sit ( unused ) for days on end is not good for the pack either.
Running the HV battery to a very low state of charge on a regular basis is not good either apparently !.
I think you can end up becoming totally paranoid about your battery !.
Then it can take away the whole enjoyment of EV driving.
We all want to do what is best for our cars of course, but not at the risk of spoiling the EV experience.
I tend to charge to suit my needs really .
With a little bit of redundancy added in just for good measure.
But if I need it, I charge to 100% without a second though.
Knowing I will be using the car for a longer trip the following morning.
Don't over think it, just use it and enjoy !.

 

[rbpasapera]

If you have the latest BMS update 100% SOC on the display is 93-ish% real battery percentage, so that you will never charge your car to 100%. I always charge mine on AC to 100% on the display.

When rapid charging, once the EV's battery reaches a certain level of its capacity, usually 80%, charging essentially slows to what would then become a fast/slow charging.

Edit: I usually top up mine to 85-ish% on DC charging.

 

[Headgas1]

Yep your right we are over thinking things because it’s so different from what we have been used to I am a total novice trying to learn as I go !! nearest thing to it is charging my mobile phone

 

[Jomarkh]

When you charge your phone do you use the charger it came with or a different one with 2 or 3A and do you let it go flat or keep topping it up?
By not charging to 100% lets the kers add power instantly and not when the charge has dropped

 

[rbpasapera]

When you charge your phone do you use the charger it came with or a different one with 2 or 3A and do you let it go flat or keep topping it up?
By not charging to 100% lets the kers add power instantly and not when the charge has dropped

After the latest BMS update, regen works great after a full charge to 100%.

 

[Kithmo]

If you have the latest BMS update 100% SOC on the display is 93-ish% real battery percentage, so that you will never charge your car to 100%. I always charge mine on AC to 100% on the display.

Even the old BMS doesn't let you charge to 100%, SOC on the app shows 97% when fully charged.

 

[Lovemyev]

After the latest BMS update, regen works great after a full charge to 100%.

Yes it does - The Regen is made available straight from the "Get Go" and it feels more linear.
I guess this is because the buffer at the top of the battery has been increased after the latest BMS update, permitting Regen at a earlier point.
I noticed it straight away after the first charge to 100%.
Not that I found anything wrong with Regen on the original OEM software, it just feels different, but in a good way.
I think you would need to drive the car in a "Before & After" situation before you noticed it.

 

[Gomev]

Interesting article. Thanks. I tend to keep my Tesla at around 75% charge - when I dont need the range which is most of the time. it has a 75kwhr pack which makes it easier to do. I charge my ZS to 100% most of the time but don’t leave it like that for long. I don’t agree with the suggestion of not charging to 100%. The article is not that well written in my opinion. My conclusion on consuming quite a few articles on this subject is as I previously mentioned. 100% is fine. Don’t leave fully charged or discharged for long. Excessive rapid charging should also be avoided if possible.

Article is also 2 years old, batteries and advice have moved on.

 

[Coulomb]

Most experts and publications recommended not charging the EV battery beyond 80%.

I agree with this. It's simply a fact of lithium chemistry, unless there is some special sauce in there to somehow prevent the bad reactions, and I don't think that any exist as yet.

I actually don't want to argue this one. I know a lot of people don't have as much time as I do to fiddle with the end of charge. So for them it's almost certainly not worth worrying about. For me, it is.