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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

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This is what I experienced as well. I further noticed that sentry mode is taking 4 mi/hr as opposed to 1. As soon as I drive the car the battery starts to go back up and taking a trip of 30 miles or more and the car only registers a 15 mile loss there. Something definitely seems off with this release.

Thanks for the report. I think there are plenty of us experiencing the same issue with this release that it’s not just coincidence.
 
Anyone else seen a massive range drop in the last couple months? I’m wondering if it’s maybe software related or maybe my battery is on its way out. 2018 mid range, less than 9k miles, down to 225 miles at 100% and dropping fast. Charges to 80% daily, superchargered 6 times in the car’s life.
CC5D48EB-C0BA-432C-9FF2-21114CA3E312.png
 
Anyone else seen a massive range drop in the last couple months? I’m wondering if it’s maybe software related or maybe my battery is on its way out. 2018 mid range, less than 9k miles, down to 225 miles at 100% and dropping fast. Charges to 80% daily, superchargered 6 times in the car’s life.
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it seems that this has affected lots of cars. not sure why they are batterygating the 3.
 
I have about the same experience as you. 2018 LR RWD with 25K miles and estimated 295 miles at 100%. Northern California so cold isn’t an issue and I rarely supercharge and charge to 80% mostly at home. From reading the forums I’m pretty convinced that my degradation is an estimation error that has been exacerbated by how little I drive now due to Covid. Following the advice of others here I’ve started letting the battery drop down below 30% before charging with the hope that over time it regains some of its estimated range.

See this thread
How I Recovered Half of my Battery's Lost Capacity

At this point, even if the degradation is real it has no effect on how I use the car.

I feel pretty much the same. With covid, I barely use the car and really doesn't impact my range of mobility.
I'll start let SOC drop below 30% next time I charge and follow the article's advice. Thanks!
 
It has affected mine. (290 miles -> 280 miles)



Do you have any evidence from SMT that they're limiting the cell voltage at 100%?

its likely amp limited not voltage limited. Tesla is actually honest about voltage limiting. 100% = 4.2V. If they deny you a charge to 4.2V it will i.e. refuse to charge above 95% or whatever.

What annoys me about this is that Tesla could just say that 90% is too high and just give us an update to do daycharge to max 83% or whatever. More than happy to only charge to there as long as i can charge to 100% when i really need to.
 
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its likely amp limited not voltage limited. Tesla is actually honest about voltage limiting. 100% = 4.2V. If they deny you a charge to 4.2V it will i.e. refuse to charge above 95% or whatever.

What annoys me about this is that Tesla could just say that 90% is too high and just give us an update to do daycharge to max 83% or whatever. More than happy to only charge to there as long as i can charge to 100% when i really need to.

I was trying to make the connection between your statement and the loss of range...current limit would not do it.
 
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yes it would because if there are less ah in the battery you get less wh.

That would be true, but you said amps.

CAC is a value you multiply by the average discharge voltage (more precisely, it is the integral of V*A over time) to give you actual Wh capacity.

What you are saying doesn’t really make sense. They can only limit the capacity by raising the minimum discharge voltage on the low side, or capping voltage on the high side.
 
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That would be true, but you said amps.

CAC is a value you multiply by the average discharge voltage (more precisely, it is the integral of V*A over time) to give you actually Wh capacity.

What you are saying doesn’t really make sense. They can only limit the capacity by raising the minimum discharge voltage on the low side, or capping voltage on the high side.

hmm true. but a car with true natural degradation still has the same voltage as a new car.
 
hmm true. but a car with true natural degradation still has the same voltage as a new car.

That is correct. Because it has less capacity. To get a feel for how it works, imagine a car which over time has 44 cells in parallel rather than 46. That would have lower CAC. Same voltage range. It doesn’t *really* work that way, because the peak current capability doesn’t change that much (44/46) with degradation. There are just fewer free ions available to move between terminals, and perhaps to some extent the chemistry at the terminals is altered somewhat so less energy is able to be extracted (more heat loss for example). The actual details don’t matter much - I am not trying to explain actual mechanisms of degradation accurately here.

Anyway. Maybe they changed the estimation algorithm. Or they are limiting discharge (min voltage), or capping the voltage. Or none of the above. I checked the constant; it’s the same of course. Need someone who has been tracking things religiously with SMT I suppose.
 
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For those guys plugging the car every day, have you tried charging to 100%, turning sentry/summon on demand/overheat protection/etc off, and then letting battery discharge to 30% or so over a few days, so the SOC is reported overnight at different SOCs? That supposedly 'recalibrates' the algorithm, for what I've read. Then charge back to 80% max. It'd be best to do that every 3 months or so. But let's hear from an expert like AlanSubie, and see what he says :).
 
My buddy got a 2018 long range AWD 22k miles from Tesla last week.
he finally charged to 100% and only got 281 and we left to Vegas from SoCal and only went 200 miles before we were under 18 miles left. Aero wheels and highway speed was about 78-80.

does 78mph really kill the range that fast? Vegas is 241 from my house so we thought we would make it all the way there.
 
Yeah, there's no freaking way I'd make that trip in one shot even on my new 2021 LR man. Maybe at 55 mph max, but who wants to do that? Part of my research was to learn about real life range, and I quickly learned the EPA numbers are just 'aspirational'. Ha ha. I live in TX, where speed limit is typically 80, and it's either hot or cold, so HVAC has to be on most of the time. That kills range too, and cold temperatures are an additional source of decreased range. You should be able to find a supercharger between Vegas and LA, and a quick charge while you go to the bathroom should get you there at the speeds you want.

By the way, on my first and only long trip so far, where it was cold, HVAC on, and speeds of 80+, my consumption was 2.5 miles per 1%, so you can have an idea what you need. Superchargers were from 98 to 147 miles, so I needed 60% charge max. It was cold and windy, so played it safe just in case, and charged between 80 and 90%, to arrive with around 30%. It worked out perfectly, and it was like I expected, so zero disappointments.
 
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