# how bad is it for the battery to charge to 100%



## og bunky (8 mo ago)

on a regular basis?

charged to 100% for the first time yesterday and enjoyed the extra range. trying to weigh risk/benefit


----------



## elelegido (Sep 24, 2014)

You will more than halve the battery life by regularly charging it to 100% and then discharging it fully compared with just using the middle 60% of capacity between 20% and 80%.










It's best to use just over half the battery's capacity and range.


----------



## Driver Larry (Nov 5, 2018)

Tesla High Voltage Battery Information

_Some Tesla are equipped with a Lithium Iron Phosphate (LFP) Battery. To determine if your vehicle has an LFP Battery, navigate to Controls > Software > Additional Vehicle Information.
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. _


----------



## _Tron_ (Feb 9, 2020)

elelegido said:


> Right, but you will more than halve the battery life by regularly charging it to 100% and then discharging it fully compared with just using the middle 60% of capacity between 20% and 80%.


Right, but you are probably thinking she was inquiring about her phone. That's what I assumed too. But after reading Larry's response I noticed the post was made in the vehicles sub-forum.

As far as what @Driver Larry said I am SHOCKED to hear of the advice to charge an LFP chemistry battery to 100% on any kind of regular basis. I am glad Larry quoted from and linked to the Tesla doc or I would not have believed it. LFP is simply a less expensive, less energy dense, chemistries compared to typical higher density chemistry employed in most EVs. But LFP (Lithium Iron Phosphate) chemistry is common in many other applications, including cell phones and solar systems. However, LPF chemistry is just as sensitive to being fully charged and fully discharged as any other lithium chemistry.

So it is SCHOCKING that Tesla is putting that out. It must mean their brilliant engineers have come up with a way to pull this off, yet stand behind the warranty. Part of it I assume is that when the customer charges to 100% it is highly likely that the battery itself is not really 100% charged, but that a buffer (controlled by the software) has been introduced. In other words, Tesla is likely only using a specific % of the potential energy of the battery,

(my expertise comes from building and maintaining my own home solar system, and all the pain-in-the-ass research about lithium batteries that went into it).


----------



## TobyD (Mar 14, 2021)

It shouldn’t matter. Your batteries are destroying the planet no matter how much you charge them.


----------



## elelegido (Sep 24, 2014)

_Tron_ said:


> Right, but you are probably thinking she was inquiring about her phone. That's what I assumed too.


This thread is in the "Vehicles" forum. The OP also mentioned range, which isn't applicable to a phone. So, no - this thread is about charging the OP's electric vehicle.











> As far as what @Driver Larry said I am SHOCKED to hear of the advice to charge an LFP chemistry battery to 100% on any kind of regular basis. I am glad Larry quoted from and linked to the Tesla doc or I would not have believed it. LFP is simply a less expensive, less energy dense, chemistries compared to typical higher density chemistry employed in most EVs. But LFP (Lithium Iron Phosphate) chemistry is common in many other applications, including cell phones and solar systems. However, LPF chemistry is just as sensitive to being fully charged and fully discharged as any other lithium chemistry.
> 
> So it is SCHOCKING that Tesla is putting that out. It must mean their brilliant engineers have come up with a way to pull this off, yet stand behind the warranty. Part of it I assume is that when the customer charges to 100% it is highly likely that the battery itself is not really 100% charged, but that a buffer (controlled by the software) has been introduced. In other words, Tesla is likely only using a specific % of the potential energy of the battery,
> 
> (my expertise comes from building and maintaining my own home solar system, and all the pain-in-the-ass research about lithium batteries that went into it).


I don't know. It's not as if car manufacturers aren't dishonest.

GM persisted with its "No working airbag for you!" cars, even though they knew they were defective.
VW said that its diesel cars met emissions regulations.
Ford says that there are no inherent problems with their Powershit I mean Powershift automatic transmissions and kept on selling them.
Toyota claims it's normal for some gasoline engines to burn a quart of oil every 600 miles (2az Camry)

Tesla misleads about the capabilities of their "Autopilot" system. It wouldn't cause much surprise to find out they've been less than 100% squeaky-clean honest in their many claims.


----------



## og bunky (8 mo ago)

I have the lithium ion phosphate battery, and the charging screen does mention to charge to 100% once a week


----------



## Snowblind (Apr 14, 2017)

Audi tells me to charge the Car weekly or whatever to only 80%. If a longer trip comes up, 100% charge is ok.
So on a 80% charge, I'm getting barely 190 miles, which is fine with me, full charge comes to 237 miles 
YMMV, literally.
😎


----------



## Disgusted Driver (Jan 9, 2015)

og bunky said:


> I have the lithium ion phosphate battery, and the charging screen does mention to charge to 100% once a week


Given the battery warranty on the Tesla I think you are quite safe in following their directions and charging to 100% every night.


----------



## _Tron_ (Feb 9, 2020)

Although I am careful to never let the battery get to low a state of charge (worse than charging too high) I do charge to 100% when I am going to be driving immediately. I actually set the car overnight to be fully charged right at the time I will be getting in and driving.

Letting a lithium ion battery sit for extended periods at or near 100% is quite different from charging to 100% and then immediately start discharging. There is a chemical reaction taking place at a high state of charge that contributes to deteriorating the cells. This reaction actually happens in degrees above or below a neutral state of 50% charge. So it's a question of how long the battery is at a particular state of charge that affects its life.


----------



## og bunky (8 mo ago)

is it bad to frequently top-up recharge via supercharger? say

80 to 40 to 80 to 50 to 80 to 30 to 80 to 55 to 80 to 20 to 80

basically if i am very close to a supercharger during a slower time period, id like to top up since i dont necessarily know when the next convenient time will be

is this detrimental to the battery? or better than the 20-80 all the time?


----------



## Disgusted Driver (Jan 9, 2015)

og bunky said:


> is it bad to frequently top-up recharge via supercharger? say
> 
> 80 to 40 to 80 to 50 to 80 to 30 to 80 to 55 to 80 to 20 to 80
> 
> ...


FRom my understanding of how Tesla's work, shouldn't matter.


----------



## _Tron_ (Feb 9, 2020)

Agreed. You will find a diversity of opinion on most any battery charging question, but the idea of topping off when possible is a good one. Batteries degrade _somewhat_ from charging and discharging, but in your case the total charge/discharge on the battery is a wash. As already noted you just want to stay away from the extremes as you can (<20 and >80).

"The Extremes" Sounds like the name of a band.


----------



## Heisenburger (Sep 19, 2016)

_Tron_ said:


> "The Extremes" Sounds like the name of a band.


Played at CPAC in 2020 ... Heard they were just as lame as the speakers.


----------

