I am charging battery to 90% of full charge. Should I decrease it to 80 or 85%?
What does your owners manual say you should charge it to? Or Teslaâs web site. Tesla designed it, follow their instructions.
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Why not charge it to 100% ?
Curious minds want to know.
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The Tesla Facebook Clubs debate this endlessly. I watch the debate, but have yet to hear a final answer. Sadly, $50K cars now come with lots of uncertainty. It_s_Me, the reason is that these tech marvels see a quicker battery degradation curve if charged to 100% each time they are plugged in.
GorehamJ gave you the correct answer. Iâll add that my father-in-law had a laptop where you could choose to charge the battery to 60% instead of 100% so that the battery would give more years of service if the reduced runtime on a single charge wasnât a problem.
Doesnât Tesla provide specific guidance on this? Iâd trust them before the opinions of folks like meâŠ
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I reviewed Tesla manual. It doesnât give exactly up to what percentage of total (100%) charge battery must be charged to. 70% better than 80%? etc.
Also I noted something else. Efficiency rapidly declines when the tire pressure goes below 37 psi in all 4 tires.
They are suggesting 45 psi on all 4 tires for economy and 40 psi for comfort.
Your manual says this. Pretty crystal clear to me:
"Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks. When plugged in, Model 3 wakes up when needed to automatically maintain a charge level that maximizes the lifetime of the Battery. "
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Doesnât that mean one has to charge more frequently? I am not a battery expert, but unless a brand new batter is already fully charged, it is recommended that they are fully charged prior to first use. I canât see why subsequent full charges would diminish a batteries life.
Lithium-ion batteries degrade over time, even without cycling.
They degrade fastest when hot and/or fully charged.
They degrade slowest when about 50% charged and cool.
Hopefully the Tesla BMS (battery management system) takes this into account when the car is plugged in for extended periods.
https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
As with every person who doesnât read the manual. How many questions do we get every week in this forum on what oil to use and oil change interval for their new vehicle. People donât want to RTFM. Itâs not an uncertaintyâŠitâs in the manual.
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Actually, Tesla is not very specific regarding how far you should charge on a daily basis, and there is a reason for that.
The reason you should leave your car plugged in when parked for an extended period is so that the car wonât skimp on power in heating and cooling its batteries to keep them in the optimum temperature range. It is not so the car will stay 100% charged like a cell phone. Remember that cell phone batteries are not quite the same design and are intended to last only 3-4 years.
Charging to 100% is just fine if you intend to start driving immediately after charging. What you DONâT want to do is charge to 100% and then leave the car parked for a week.
How high you charge (80-85-90-or more) depends on how big your battery is, how far you need to drive, and how long the car will be parked after it is charged. Our utility rates go to minimum at midnight, so we set our long range model 3 to start charging at midnight at 32A. In the morning, it is charged to our setpoint (usually 80-85% but may be higher depending on plans for day) and ready to set out for the day.
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Iâm fascinated by the number of people who find it easier toâŠ
find this forum via a Google searchâŠ
create an accountâŠ
log-inâŠ
and create a post with their queryâŠ
When it would be quicker, easier, and far more authoritative to simply reach over to their glove box, retrieve the Ownerâs Manual, remove the plastic over-wrap from the manual, open the manual, and actually⊠READ⊠what the vehicleâs manufacturer had to say, rather than accepting opinions from anonymous internet strangers, all of whom have unknown credentials and unknown agendas.
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hey, you are completely skipping the fun part of it 
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Then that is the answer isnât it.
If I recall, you can choose the charge level that gets used when the car is plugged in. So even if you leave it plugged in for 5 days, if you chose an 80% charge level, thatâs how high it will go before reverting to maintenance charging.
The general consensus amongst EV drivers is to charge somewhere between 70 and 90% unless you need the full range, with a âbalanceâ charge to 100% every month or so.
Also keep in mind that Tesla limits battery packs via software. So, for instance, a 75kwh Model S actually has an 80khwh battery in it, and software prevents it from ever being fully charged (though Tesla is known to override that software limit to extend the range in emergencies such as hurricane evacuations). So even if you charge to 100%, you may not actually be charging to 100%.
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So it seems that Tesla has already taken this into account. I donât understand how general folks, techies that they might be, think that the standard settings uploaded by Tesla to their sophisticated charging system are somehow wrong. Has there been any evidence to support this? Folks relying on what they do with their laptop doesnât countâŠ
The point is that there is no standard setting. You can choose what charge level the vehicle gets.
And Tesla isnât taking battery longevity into account when it limits the max charge level, itâs taking wanting more money into account. You can pay them money to unlock the extra capacity of the battery. Itâs akin to choosing the F150 with 1 or 2 fuel tanks, only with Tesla, you donât have to sell the car and buy another one with larger capacity, you just up-rate the one you already have.
Should OP choose to do that, or buy a car with a battery that actually is the size indicated on the box, then itâs entirely possible to charge it to a true 100%.
The manual says to leave it plugged in, and the system will control the charging. So Tesla does have a âstandard settingâ. Folks just donât seem to want to use it.
Again, yes, leave it plugged in and the system will control the charging, which means the system wonât keep pumping full power into the battery after itâs reached the chosen charge level.
All choices for charge levels are âstandard settings.â To try to explain, think of a TV. It has a volume control. All volume levels from 0 to 100 are âstandard settings,â and you choose what setting you want (and the TV will then maintain that setting if you leave it plugged in). If you choose to put it at 100% all the time, you might blow a speaker earlier than if you keep it at 80%. But theyâre still standard settings, and the manual may or may not mention that the highest settings can cause earlier failures.