LFP battery, charge to 100% each night?

[BrianScott1980]

I’m looking for some advice. I’ve picked up my new MIC SR+ today. Build quality is superb. The battery is LFP based and the charge screen shows 100% available on the charging scale. The car even had 98% charge when I collected it.

What’s the recommended charging routine for the LFP? Can I charge to 100% most nights without fear of battery degrading? I intend to keep the car for at least 5/6 years.

 

[Steely]

Sorry if this is a daft question, but as all batteries degrade over time why do you need to charge to 100% every night. If you had a petrol or diesel car would you go to the petrol station and top up every day?

 

[[email protected]_MCS]

Sorry if this is a daft question, but as all batteries degrade over time why do you need to charge to 100% every night. If you had a petrol or diesel car would you go to the petrol station and top up every day?

The recommendation from Tesla is to plug in everyday, even if you don't need a 'Top Up'. I'm not sure of the exact reasoning but it seems the car is designed for daily charge using slower connections like 7kw from home.

@Brian - I don't think you need to go to 100% every day. Take a look at the video below, this helped me understanding the new LFP battery. Seems the trade off is slower charging but it doesn't care if you go to 100% each day.

 

[BrianScott1980]

The recommendation from Tesla is to plug in everyday, even if you don't need a 'Top Up'. I'm not sure of the exact reasoning but it seems the car is designed for daily charge using slower connections like 7kw from home.

@Brian - I don't think you need to go to 100% every day. Take a look at the video below, this helped me understanding the new LFP battery. Seems the trade off is slower charging but it doesn't care if you go to 100% each day.

Great. I’ll check it out. To be clear I don’t need 100% range every day. But the previous advice of keep topped up to 80% doesn’t seem to apply anymore to LFP. I’m trying to work out whether regular 100% charging, say twice a week, will have a detrimental impact.

 

[bryand]

Connecting the car every night is so it can download and install updates, most of which need the car to be plugged in. If you don't need it charged up to 100%, don't charge it that high.

 

[Hurricane]

9

Great. I’ll check it out. To be clear I don’t need 100% range every day. But the previous advice of keep topped up to 80% doesn’t seem to apply anymore to LFP. I’m trying to work out whether regular 100% charging, say twice a week, will have a detrimental impact.

When I picked my car up in Sept 2019 the Tesla people assured us that charging to 90% on a regular basis was absolutely fine. Not sure where the 80% recommendation comes from but plenty of people are convinced that’s the advice.

 

[Wol747]

I think that for a new owner charge it up to say 90% until you get a feel for how the achieved mileage looks versus the screen projection - any range anxiety will quickly disappear. Then set the charge level to what you feel gives you a comfortable range for your likely trips. It doesn't matter what the battery is, IMO charging to over 80-90% doesn't do much for the car so long as you don,t see the need for that extra bucket of electrons the next day.
What IS happening with the Ss recently is that the car will switch on and charge every five minutes indefinitely with the associated whirrs, clicks and bangs - it's doing it on mine and many others'. So I have to charge up and then unplug it for a few days - I'm in process of doing this and recording the vampire drain.

 

[Tigermad]

My new car will have the same battery. I am not sure you will get regen breaking if it’s topped up to 100 every time.

 

[Chippylad]

My new car will have the same battery. I am not sure you will get regen breaking if it’s topped up to 100 every time.

I am sure that you won’t get regen at 100%

 

[DJP31]

Connecting the car every night is so it can download and install updates, most of which need the car to be plugged in. If you don't need it charged up to 100%, don't charge it that high.

The car absolutely does not need to be plugged in to download and install updates.

 

[nxsynjs]

As you get more confident in the car you'll learn to only charge the car to what you need (plus a 5-10% Margin) until you can charge it next. Not only will your battery thank you(computers canna change the laws of chemistry) you'll save money by not spending money on a charge that will effectively not be used.

This guy has done a series of videos on the battery, range etc which I have found very useful

 

[Alistairuk]

I think the 80% thing has came from other manufacturers recommendations and been inadvertently shared by others through YouTube etc so has kind of became a standard. I’ve also found “regenerative breaking limited” warnings when above 80-85% charge but I can’t 100% say this is down purely to battery level so that may also have been brought in when people say 80%

As you say the Tesla manual recommends charging to within the daily range on the battery screen (I think this is between 50-90% but can’t remember off hand) I leave mine set at 90% as I’m so far only charging while out and about as I do very little actual driving since getting the car in September - a top up once a week down local park while walking is enough for me and saves me paying for electricity

When I start using it more daily I’ll have it set to enough to allow me to do what I have to do with some spare - purely to avoid paying for electricity unnecessarily

You’re unlikely to damage the battery beyond normal degradation unless you routinely charge to 100% and leave it there for days. There’s plenty of social media people over in USA who aren’t car fanatics who only charge at super chargers several times a week and so far none of them are complaining their batteries are fried

Also if you have the free supercharger miles - don’t avoid using them as I’ve ended up only using 200 odd and lost the other 800

 

[Envchem]

Don't charge to 100%. Unless you need that range on a daily basis don't do it. It will degrade the battery. Plenty of evidence online. 90% charge is fine if you want to feel safe from a range point of view. 90% does not affect regen. I charge at 90% on daily basis and the only times I see restrictions on regen is when I haven't preconditioned the car. 25k miles under the belt at the moment and I have 1% degradation. Car is getting charged from 40% to 90% 5 times every week(unless I am on holidays).

 

[Drew57]

you'll save money by not spending money on a charge that will effectively not be used.

purely to avoid paying for electricity unnecessarily

I don't see how charging vs not charging will actually save money. Unless a battery is allowed to fully empty & stay in that state, it will gradually deplete regardless of whether it's topped up or not. There will be 'cost' either way.

Top up at a high charge with a little or at a low charge with a lot, the end result is the same & it's always draining to some extent.

 

[ACarneiro]

Don't charge to 100%. Unless you need that range on a daily basis don't do it. It will degrade the battery. Plenty of evidence online. 90% charge is fine if you want to feel safe from a range point of view. 90% does not affect regen. I charge at 90% on daily basis and the only times I see restrictions on regen is when I haven't preconditioned the car. 25k miles under the belt at the moment and I have 1% degradation. Car is getting charged from 40% to 90% 5 times every week(unless I am on holidays).

I’m not sure that evidence is applicable to the “new” LFP chemistry, though?

 

[Jason71]

There were stories that the LFP can and even should be charged to 100% once a week
e..g.

https://twitter.com/i/web/status/1316769191928627200

from Tesla aledgedly Obviously that goes against everything we have been conditioned to do with all EV's to this point so it feels wrong but I would be unhappy to advise the op one way or the other without more evidence which we just don't have.

If they are advising that does that mean the battery has memory!!! thought we were done with that
Even if I was going to charge an LFP to 100% once a week if I had one not sure I would hold it there for long. Cant imagine that has any benefits and may be detrimental

 

[bay74]

I’m not sure that evidence is applicable to the “new” LFP chemistry, though?

Yeah that was the whole point of this question right? Specifically about the new chemistry.

And yeah I wouldn't simply because then you have no regen braking to start with.

 

[Envchem]

Since the chemistry of the battery is new and there is no evidence of how it will actually perform on the long run I would be hesitant to push it its limits. We have seen Tesla changing their mind in the past regarding what should or should not be done and how they have nerfed charging speeds for older S models. I would be cautious.

 

[Adopado]

I am sure that you won’t get regen at 100%

Based on the previous battery chemistry that would be true ... however, if the pack is really designed for frequent 100% charge then it's possible they have allowed a buffer at the top end that would allow regen even when charged to 100%. We can get the answer to this question from somebody with an LFP battery pack ... so do you get regen after charging to 100% ?... we need to know!

 

[Arran]

What does the car screen 'suggest' for daily use? When you click 'Set Limit' on the charge screen there's a Daily and Trip Indicator.
Assumingly if Tesla recommends charging up to 100% on the new LFP pack the daily limit should be 95%+

Curious to see if it's any different.