100% Charging - Negatives

[ibdb]

You're asking for answers based on experiences that people haven't yet had with the (relatively) new Model 3.

We know from past experience that relying heavily on Superchargers has been a negative for the Model S. Charging rates have been limited by Tesla to protect the batteries. Actual amounts of degradation are difficult to quantify because driving environments differ, but there does seem to be a small amount above what would normally be expected that can be linked to heavy reliance on supercharging.

Tesla's own recommendations have varied a bit, but the latest word seems to be that using 90% as your charging target is the best for long term battery health, but that charging to 100% if you're going to use it is perfectly acceptable. Your mileage, quite literally, may very.

If you do choose not to accept the recommendations that others have already given you in this thread, you will see more than "normal" battery degradation. Over time, your battery will no longer be able to charge to the same level. A 100% charge may then only give you the equivalent range of what an 80% charge provided on a new battery. No one here knows yet exactly how long it might take for you to experience that.

 

[Electricfan]

I hate to tell you this but there is another problem with charging as you are suggesting - Tesla will slow your charge rate after using a supercharger exclusively. The battery isn't built to charge soley by supercharger. Tesla expects you to slow charge it overnight, not blast it at a supercharger every single time you charge it.

No, I don't know how many charges will trigger the slow down. No I don't think anybody at Tesla will officially confirm this. But there are lots of threads on the forum about it.

Your top priority should be finding a non-supercharger solution to charging your battery for daily driving. As long as you're only charging at a supercharger, I wouldn't charge it above 70%, for daily driving.

I'm sorry if you're not getting the answers you want. All you're ever going to get on a forum is the best opinions of other owners. All well-meant. Call Tesla if you want "official" info. And please post back here with anything specific they tell you!!

 

[DSMLVNV]

I hate to tell you this but there is another problem with charging as you are suggesting - Tesla will slow your charge rate after using a supercharger exclusively. The battery isn't built to charge soley by supercharger. Tesla expects you to slow charge it overnight, not blast it at a supercharger every single time you charge it.

Is a wall charger at home considered "slow charge?" The $500 one?

 

[TexasEV]

I hate to tell you this but there is another problem with charging as you are suggesting - Tesla will slow your charge rate after using a supercharger exclusively. The battery isn't built to charge soley by supercharger. Tesla expects you to slow charge it overnight, not blast it at a supercharger every single time you charge it.

Is a wall charger at home considered "slow charge?" The $500 one?

Compared to supercharging, yes, by an order of magnitude. Supercharging peaks at about 117 kW. The Wall Connector charges the Model 3 at 11.5 kW maximum (240V x 48A).

 

[DSMLVNV]

OK, so it's your opinion I get a wall connector, period? I am planning on moving soon anyway. That seems to be the best option, correct? How many hours does it take to charge from say 10% to 80%? And what does it cost to install? I know it's $500 for the unit. I've heard $2k for install? Seems insane. I paid an electrician $150 to install the one I had for my BMW i3.

 

[dhrivnak]

The 0-100% charge will add 1-3% extra degradation per year.

What does that mean specifically?

It means that after 10 years you will have lost 30% of your range. If you were to have normally charged to 90% you will likely have 90% of your range left.

So I normally charge to 80% (250 miles) BUT on trips I do move it to 100. Another plus to not charging to over 90% is I have full regeneration saving brakes and extending my range.

Starting each day with 250+ miles is more than enough for every day use. For us over 200 miles is a planned trip not an everyday occurrence.

 

[dhrivnak]

OK, so it's your opinion I get a wall connector, period? I am planning on moving soon anyway. That seems to be the best option, correct? How many hours does it take to charge from say 10% to 80%? And what does it cost to install? I know it's $500 for the unit. I've heard $2k for install? Seems insane. I paid an electrician $150 to install the one I had for my BMW i3.

I just purchased a second mobile connector. Only $300 and the 32 amps has always fully charged me overnight. And an extra NEMA 14-50 is a nice addition to any garage. Good for welders, RVs, big freezers, compressors and yes an EV.

 

[Eno Deb]

OK, so it's your opinion I get a wall connector, period? I am planning on moving soon anyway. That seems to be the best option, correct? How many hours does it take to charge from say 10% to 80%?

At the bottom of this page you'll find a table that tells you how many miles/hour you can charge depending on the ampacity of the circuit:

Wall Connector

As mentioned above, the Model 3 maxes out at 48A (60A circuit minus 20% continuous load safety margin).

Unless you have an extremely long commute, chances are that you will even be happy using the mobile connector with a simple 30A dryer outlet (which would allow you to add about 170 miles of range in 8 hours overnight).

And what does it cost to install? I know it's $500 for the unit. I've heard $2k for install? Seems insane. I paid an electrician $150 to install the one I had for my BMW i3.

That depends a lot on your existing installation.

 

[mswlogo]

OK, so it's your opinion I get a wall connector, period? I am planning on moving soon anyway. That seems to be the best option, correct? How many hours does it take to charge from say 10% to 80%? And what does it cost to install? I know it's $500 for the unit. I've heard $2k for install? Seems insane. I paid an electrician $150 to install the one I had for my BMW i3.

Well how many watts was your i3 charging at? You can choose a wide range of charge rates for your Tesla. And a Wall Connector is NOT required. But it offers a bunch of perks. Like it’s designed for outdoor use, can charge at a higher rate (on circuits above 40A) and can be synchronized with other wall connectors to charge multiple cars on a single circuit. It all depends on what’s available in your panel, what you want and where you want it. Might cost $150 for 240V 20A outlet near your panel. Or it might cost $5000 if you need a new service panel because you want 60A and your garage is 500 feet from the house. Every install is unique. But more watts cost more $$$. And it’s not linear. Nothing insane about it.

30A 240V cost me $100 (DIY job) and changes at 21 mph. Probably would have been $250 to have it done.

To my understanding what impacts longevity is your AVERAGE state of charge. In other words if you charged 20-100% once a week vs 80-100% every day the later would have a much higher average SOC and shorten the life of the battery way more than 20-100%. So when people say don’t charge to 100% it’s not clear which case they are referring too. I suspect if you did 20-100% once a week and immediately drove it enough to use say 10% each time I suspect it would be fine. I don’t know if you’d still get the 100% too often warning or not.

I think if your going out to just get “fuel” waiting for that last 10% when charging to 100% will get real old quick. Last 10% takes a good hour. Last mile or two is at 1kw. It’s generally not worth waiting for.

 

[Tslrsx]

It means that a new 100kwh battery Will only have 80kwh of capacity left when fully charged after the degradation.

So, in layman's terms, does this mean, I can never charge past 80%? Meaning I can never charge more than approx. 248 miles?

It means that when charging to 100% it Will only show 248 because you lost 20% of the capacity

 

[SilverSp33d3r]

Just charge to 100% everyday and see what the car tells you.

 

[Olds442]

tesla recommends charging to 90% unless you need the extra range and to charge to 100% like when you are going on a long trip.

did you follow BMW's recommendations with their car?

 

[DSMLVNV]

Let's cut to the chase here. I only put on about 6,000 miles per year on my car. I am away for work much of the time. And I work from him when in Vegas. I don't think I'm going to be able to move, for family reasons, into a house from my apartment complex for at least a few years. Thus, I have no ability to charge whatsoever except at Super Chargers. Was this a massive mistake to buy the M3? Should I take the financial hit and sell it? It has under 300 miles. And I love it to death. But if I'm going to ruin the battery, not so sure I like that idea. Please advise. Thanks everyone!

 

[SilverSp33d3r]

Please explain why you need to charge to 100% if your not driving daily?

 

[DSMLVNV]

I'm over that. I get not charging to 100%. I'm just concerned now that if I can only use a Super Charger that I'm going to kill the battery quickly and maybe this was a mistake to buy?

 

[sjg98]

I'm over that. I get not charging to 100%. I'm just concerned now that if I can only use a Super Charger that I'm going to kill the battery quickly and maybe this was a mistake to buy?

This is a question of interest for me too. Another low-mileage all-supercharging owner here.
On track to do about 6000 miles/year, no access to charger at home or work.
I charge to 80-90% every 2-3 weeks, usually at an Urban (72kW) supercharger and occasionally at a full supercharge.

 

[dusdev]

Based on your use case, I'd say charge to 95-100% at the SC. If you're only doing 6000 miles/year that would only be at most about 20 supercharging sessions per year. I think you're going to be fine. That's going to be different than someone doing a full 100% SC every other day which would cause a lot more battery strain. 20 times per year is nothing to worry about.

 

[SilverSp33d3r]

I average more than 6,000/year from Superchargers with a 2014 s60. In one year approx 12,000 of the 20,000 was on a supercharger. My battery is degrading similar/ less than others here using supercharging less.

FYI if your in Vegas there is also a TON of destination chargers. You could spend the day on the strip and charge for free at one of the casinos.

 

[Olds442]

You aren't limited to just superchargers, Las Vegas has "Charge Point" chargers listed all over the place, download the charge point app and it shows all chargers, not just theirs. All of them are listed.

Just charge to 90% when it gets to 20% and enjoy the car.

 

[AlanSubie4Life]

EDIT: Getting to your question about Supercharging...

I think I would try to find a way to trickle charge at work or at home (at your apartment) if you can find a way. It's a lot more convenient than a Supercharger for routine use. You are losing the benefit of having a car with a high state of charge whenever you leave home by not having a means of charging at home. A trickle charge will be relatively inefficient but probably doesn't matter to you too much.

I don't think people can tell you what is going to happen with routine Supercharging, for the same reason they can't tell you what will happen with charging to 100% - it's a new battery module - not the same as Model S/X. We'll see, but if prior Tesla experience is anything to go by, it is probably going to be fine even with frequent Supercharging (see Tesloop). As good as not doing Supercharging? Maybe not. But that's not the main reason to avoid supercharging - it's the inconvenience of SC (and destination charging, to a lesser extent) that you would like to avoid, in my opinion.

Not knowing the specifics of your apartment situation, it's hard to know whether you should invest in a charging solution there. I do think you should have a good way to charge at home if you possibly can make it happen.

It means that a new 100kwh battery Will only have 80kwh of capacity left when fully charged after the degradation.

So, in layman's terms, does this mean, I can never charge past 80%? Meaning I can never charge more than approx. 248 miles?

EDIT: I guess these questions have already been answered...sorry. I'll just leave this post here anyway.

You can charge past 80% if you need to. I charge to 90% when I need it. Max I have done has been 93% and I was very glad I did.

You're not getting specific answers here because actually no one knows how these batteries will do - we have historical data from Tesloop vehicles, etc. (they may give information on how high % they charge to), but those battery packs are actually different than the Model 3 pack - it's a different base cell that is used, both in form factor and (I think) the exact cell composition, and it may not have exactly the same characteristics!

However, basic guidelines for Li-ion batteries, and the chemistry of these batteries, suggests that keeping them in a 30-70% (or 80%) charge range is "ideal". You can adjust those percentages if you need to, and it's not a problem to go outside of that range sometimes. Personally I'd just try to get it back in that range as quickly as practicable.

I would just figure out what you actually need to charge the battery to for your needs, add an extra 10-15% buffer, and enjoy. If you need 310 miles of range (real world max is 260 miles or so for you), charge to 100%. Definitely don't store the vehicle at 100% though.

You may want to get a new 18" wheelset with MXM4s if you really need the full range. You'll probably maintain a healthier battery since you'll be able to charge to a lower percentage more frequently. Think of the additional cost as being offset by a little better range, lower energy costs, peace of mind, etc. Note your stopping & handling performance will be negatively impacted (though it will be completely fine for normal driving).