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Good call. Save yourself the stress and focus on enjoying your awesome ride. The best way to begin doing so is by changing the display so that it shows percent instead of miles. Everyone should do this now and just forget about what the Guess O Meter thinks it has available in terms of...

That's a confusing way to think about it from my perspective, after all, a 1C charge rate takes longer than an hour because you're referring to the peak rate only.. The time it takes to refill the batteries' full capacity is dependent on the size of the top buffer. The C rate is purely how fast...

C-rating is used to describe the charging/discharging profile of a battery, where C is the capacity (usually in amp-hours, but it is often described in kWh as well). So if you refer to a 1C charge rate, and you're dealing with a 100kWh battery capacity, your charge rate will be 100kW. 2C would...

+1 From my experience, this is due to the effect that temperature has on the SoC. For example, after completing a charge at 10kW, the pack will have an increased temp which raises the SoC from the BMS’s perspective, and there‘s probably a delay in the max pack temp after the charge stops due...

‘Reassuring’ is better, but even that still implies that this number holds some weight when evaluating range, which I argue it does not. Lithium batteries simply do not degrade at this rate, unless exposed to some outside influence (extended high temp exposure, extreme deep discharge without...

It makes me cringe when we refer to this number as being 'really good.' Suggesting that this number is either good or bad is very misleading as it is almost meaningless and should never be used to evaluate.. anything.

The range reported on the dash is just a guess and does not represent what you can expect after considering how you drive, weather conditions, etc. As mentioned already, the best way to understand how much range you can expect is by factoring in your average rate of consumption and do the math...

Whenever I‘m away from my Tesla for a longer period of time, my main concern is the possibility of depleting the battery if it’s unable to charge. This would be devastating to the battery if left depleted for more than a few hours. This is why it should be left plugged in, with a charge set...

I‘ve definitely thought about swapping the 12v out for a lithium solution, but they’re still quite expensive and, as others have mentioned, are not yet refined enough to survive all of the extreme conditions that the car and lead acid battery can. Lithium batteries have been available for...

Good call. Climate certainly plays a factor in how long they last. The point is, change it as a preventative maintenance item at whatever interval makes sense for your usage/climate, do not wait for the EV to tell you that it needs replacement as it will always be too late when this occurs.

Having gone through this before with my i3, I can confirm that it was quite scary with my entire family in the car. Unfortunately, until this happens to you, you won't understand just how impactful it is when the 12v battery fails in an EV, especially while driving and without any warning. The...

The goal should be to cycle the pack around 50% SoC. Depending on how much you drive the car will determine where your charge setpoint should be. For example, I only drive about 25 miles round trip every day, so I've got the charge setpoint set to 60-65% generally. I would then plug it in once...

I’m not disagreeing at all with that. I guess you’re not understanding how I choose to explain it. From my perspective, you’re basically repeating/reinforcing what I already said about voltage. Feel free to try and explain it better if you get what I’m saying.

Agreed. Each unit of measurement is intended for different types of circumstances/applications. Voltage is obviously important to know in order to have a holistic understanding of a battery or power system. The confusion begins by not recognizing when it's appropriate, and when it isn't, to use...

If anyone is not familiar with who Bjorn is, you should take a second to watch some of his videos on YouTube. He does a great job evaluating various EV‘s from all manufacturers and he is not shy about getting into the details. He has multiple videos that go over degradation tests, the process...

Someone can correct me if I’m wrong, but I believe that it will charge it immediately to some SoC value before it stops and waits to charge the rest of the way. A setpoint of 80% may be low enough that it charges to setpoint immediately, without stopping to wait at all. Only when the setpoint is...

Yup, agreed. While using the Open Circuit Voltage can help the BMS with maintaining calibration of the SoC value, it says nothing about how much capacity has been lost from degradation. Using voltage to understand capacity is highly inaccurate, it is nothing more than a guess.

The scheduled departure feature does not factor in your utility rates to avoid charging during peak times. It will start the charge based on your current SoC, charge setpoint, selected charge rate, and departure time.

Not suggesting you add a generator. I'm suggesting an input connection for your electrical panel to feed the solar power into your home during a power outage.

Very cool. Who needs a Power Wall!? I've done something very similar (Victron FTW), but mainly as a battery backup solution for my home since solar output is far from ideal in Seattle. Have you considered adding a generator input connection to your house's electrical panel so you can use it in...

I‘m an engineer as well, and this is how I would explain the difference between kWh and Ah. Kilowatt hours is a measurement of the power to do the work, while amp hours is the energy stored prior to involving any work. There is an important difference between the two, especially when trying to...

I‘m just clarifying that the energy buffer exists at both empty and full SoC. If you don’t specify the top or bottom buffer, I assume you’re referring to the total combined.

Forgot to also mention that the energy buffer is intended to protect the empty and full states of charge, therefor there is a ‘top‘ and ‘bottom buffer.’ Some of that 3.1 kWh is for the top buffer.

Be that as it may, I can assure you that lithium batteries do not like spending longer than necessary at a state of charge below 10%. This is represented by an increased rate of battery degradation. Bottom line, the best way to hurt a lithium battery is to leave it at a very low SoC, even if...

For the record, I do not suggest ever letting it go overnight with a SoC below 10%.

They run the battery through a series of tests and incorporate the CAC (calculated amp hour capacity) to evaluate battery degradation. Once again, this is yet another example of just how misleading your method is when it comes to understanding battery degradation. To understand degradation, you...

I take it that this is surprising to you? To me, it isn't. You're reinforcing the fact that the capacity that the BMS reports is what it thinks it has access to. The ONLY way to truly know what it has in terms of available capacity is to drive it and do the math. Then, and only then, can you...

Not true.. When you adjust the charge level slider to 100%, the max estimated range is displayed, nothing more. The difference between advertised max range and this estimate is not how you understand the health of the battery, period.

There's nothing ironic about it from my perspective. You're helping the BMS see the capacity that was invisible to it by demonstrating that there is in fact available capacity beyond what it was estimating.

Yes, you can* travel further than what is displayed.. because this is not dependent on whether or not the BMS sees the available capacity. In fact, there was an article that was recently posted about this particular subject, which I think was on electrek.co. Unlike a ICE's gas tank, an EV's...

I have no doubt that the benefits of the 4680 design will be quite desirable. The faster charge rate, reduced thermal limitations/requirements, increased efficiency are going to be impressive. Having said that, personally I would prefer to invest in a solution that has undergone some...

To clarify, cycling the battery around 50% SoC is the ideal scenario for longevity in my opinion.. it doesn’t have to be as close as possible. For example, I generally cycle the SoC between 35 and 65 since our MY doesn’t travel more than 100 miles every 4 days. This equates to charging every...

Many will explain how that would be dependent on your situation, such as how far you travel daily and your charging options. Others will explain the simplified approach, which is to charge to no more than 80-90% for daily use and only charge to 100% when absolutely necessary, such as for long...

The 4680 uses dry cell battery tech, which is different than a solid state battery. You're correct that the 4680 doesn't use a traditional electrolyte, so no liquid acids or gels. Instead, it uses pressure to compact a powder material into a film. Next year is looking much more likely than it...

I have a relative that works in the prototype battery production area at the Fremont factory, so I learned of this about a month ago.

The battery tech involved with the 4680 cells does not involve solid state battery chemistries. Instead, the 4680 involves a 'tab-less' design, which greatly reduces the distance that electrons have to travel through each battery cell. This increases efficiency, reduces the heat that's generated...

You must have one of those one in a million packs that actually reaches advertised values. :p In my opinion, this estimate is related to the resulting cell temperature at the end of a supercharge and the low miles on the odometer (best state of battery capacity calibration is at delivery)...

Short trips will always use up more energy, this is normal and should be expected. The fan/pumps that are running after parking the car are related to the Battery Management System and it is perfectly normal for them to run for around an hour after the car is driven, no matter how short the...

As long as the car is in Drive with the supercharger set as the destination, it should precondition the battery, even when stationary.

All lithium batteries definitely experience a small, but sharp, drop in capacity when new. After a short while, the rate of this drop in capacity plateaus. The outside factors that can influence this rate are well understood and the BMS is equipped to avoid these situations. This is why there is...

Its simple. You’re describing how much energy the BMS sees.. I’m talking about how much actual energy the BMS has access to. Your evaluation is an assumption. Bjorn’s approach removes all assumptions and recognizes the limitations of the BMS when it comes to understanding the true capacity.

Has anyone considered the fact that Tesla always is conservative initially with their BMS parameters to preserve the health of the pack? These parameters are adjusted as more data is collected from the fleet. Eventually they unlock more performance by tuning the BMS to be less conservative after...

This is not enough data to make such a conclusion. Until you go on a long +300 mile trip, starting from a full charge, and try to extract the most range possible using appropriate techniques, you’re making a big assumption about the health of your battery.

What I'm trying to understand is how many are jumping to conclusions and blaming battery degradation without doing any thorough real world tests before making such a claim. I highly doubt that anyone goes through what Bjorn does to properly evaluate battery degredation, after all, it's a very...

I have a question for those that are concerned about battery degredation.. When was the last time you went on a trip that was over 200 miles one way starting from a full charge?

I stand corrected. Thanks for clarifying. I was thinking about the other scenario where the breaker is larger than the wire/receptacle capacity, sorry for the confusion.

By code, you cannot install a 14-50 outlet on a circuit that's rated for only 40 amps. That would require a 50A circuit. As already suggested, the 14-30 would be your best option.

But the wall connector specs 36 mph, or 9.6kW.

I swear I get 38 mph, or 10kW exactly, when charging with my Juicebox, which is connected to a 50 amp circuit. If that's the case, I guess it's safe to say that the Juicebox is faster than both Tesla chargers when connected to a 50 amp circuit. Another plus to the Juicebox is it's ability to...

Yes, cabin preconditioning will automatically turn off after 4 hours.