Search results

Here are the links i was referring to: Guangzhou: 广州一辆Model S发生自燃，没有充电，也没有发生碰撞-锂电池-电池中国网 Shanghai (well known): Tesla spontaneously combusts in Shanghai parking garage Hong Kong: 【獨家】Tesla停車30分鐘後離奇自焚爆炸 車主逃過一劫 I have >20 fires while parking in my list. A Nio with NCM811 caught fire around that...

And condition "X" or "Y" neither?

It's about the way of thermal coupling between the cells. Has advantages and disadvantages. Imho the advantages weigh out the disadvantages. Statistic speaks for M3 on first sight too. Better support for longevity of the pack too. But we are OT. Could you please give condition "Z" a name that...

5 i've seen on pics/videos but was not able to find any further information in the web, respective information was removed after some time for some reason.

Model 3/Y battery pack has advanced thermal propagation protection that's true.

Sorry, circumstances. 105 of those should be commonly found in the web. But back to topic?

Just for statistics: I know about 110 Tesla fire incidents, which include all of these reasons: Fire when parked and not charging Fire when parked and connected to DC or AC charger Fire while driving Fire while transport by carrier (trailer or train) Fire while in repair shop Fire while at...

Every accident is different. The battery pack is a lot more vulnerable to cell damage when crashing with poles, trees, concrete barriers, etc. But you are right this is OT.

In a new cell there is always excess lithium, so the loss of capacity is not directly proportional to the loss of cycyleable lithium. How much excess lithium a manufacturer uses in a new cell is a question of the wished safety class, but also from the chosen electrode balancing.

No, the nail test is a standardized test which uses a steel needle to puncure the cell in order to provoke an onset.

Here a littlebit of statistics about Tesla 2016-18 Model X non crash or vandalism fires in relation to gas cars (100 ist the average of all observed cars):

All the mess with capping started with 3 fires in parking lots in China when Tesla was forced to react by chinese authorities.

Here the older evaluation of the Model S compared to a ZOE:

Concerning safety there are many things to consider, in Tesla's design some things are very good other good and other bad. Where you always start is the safety of the cathode raw material itself (chemical issue). Here a comparision of the eneregy release of different (partially outdated) raw...

This is a revaluation of the battery from a Model S, they inspected 2 years before. In this point (overcharging protection) Tesla and other manufacturers did a good job and the valuation got better. In general, european manufacturer stated a self commitment to not use hazard level > 4 components.

The values from the chart are values you can't measure from outside. You always have the equation CV=PoC-PoA, where CV= Cell voltage at current =0, PC= Potential of Cathode, PoA= Potential of Anode. A battery with a li-plated Anode has not the same charging curve anymore as a new battery. A...

In this chart i already posted you can see that the risk of an onset caused by mechanical damage (nail) gets higher with the cathode potential rising. 4,14V EoCV means ~4,23V cathode potential:

Fatal fiery crashes in August: Two men killed in fiery crash in Thousand Oaks Saratoga: Man killed in fiery crash identified

Keep away from the SoC area where cooling pump needs to be in operation. And enjoy the summer. I'm sure Tesla will cap stricter next winter again. And good luck with your lawsuit!

Your loss is far away from the one at 4,14V. In general parasitic losses increase with battery age, but are just a part of the the whole vampire losses. In August already 4 people died in fiery crashes in Tesla cars, so my concern is more in safety than consumption.

~88% for a new battery at 25°C

Yes, I took SMT values from draingate affected users in german TFF in order to calculate the coarse waste heat combined for anode and cathode. The result was shocking. Even if you consider best case conditions at the anode, there remains a lot of waste heat which must result from cathode.

Guys, when i saw Guillaume's TeslaFi scan, i got shocked. This battery imho does definitely not qualify for an increase of EoCV. Don't know what Tesla is doing there. The amount of parasitic waste heat is definitely proving massive Li-plating and charging to 100% (~4,14V) may result in rapid...

Could you please provide some SMT scans in order to estimate the total draining energy caused by the system in this 2,5hrs.? Three scans (beginning, mid, end) would be sufficient.

I wish you all good luck with the legal action. Maybe this chart from a manufacturer of cathode raw material can be a help too? Its about nail penetration and hot box test with different cathodes/potentials, so is not directly related to the Li-plating problem but shows very well the risk of...

Sorry guys for not further following the thread. Droschke asked me to give an answer on the above theory: No, the way Tesla handles the matter is correct. They (pre)heat now by the external battery heating to ~45°C and reduce charging current esp, at higher SOC. This is the best way to prevent...

The result is a higher discharge of Oxygen. Please note that higher temperatures will degrade the electrolyte too, but in comparison to electrolyte degradation at the anode from Li-plating this is a secondary effect.

Yes they may. If Tesla uses topping off for thermal reasons should be worth to observe?

Yes but NCA cathode may. You should always avoid high cell temperature when not needed (supercharging, insane/ludicrous mode) to maximize battery life.

Heating the cells by high initial charging current using high internal resistance (below 30% SoC) was the way Tesla went before and was part of the problem in case the battery was really cold when arriving at supercharger location. Now they preheat by the thermal management before reaching...

As a P owner you may preheat the battery manually to ~112 degrees before supercharging in cold condition. And to be on the safe side, better don't park the car with > 80% SoC in your garage.

In general no, but on a li-plated anode dendrites may grow more easily.

Most people heard of dendrites and do think shorts between the electrodes provoque the fire of a battery pack. Maybe its worth looking a little deeper into the propagation protection of your battery: Every cell in your battery is part of a block of 74 parallel cells. All cells have a CID, a...

Indeed i posted the necessary amount of EoCV reduction in another forum around 6 weeks before this thread started.

Sure, but this is not the main reason for the EoCV reduction, charging power reduction and the changes in thermal management. Simplified you can consider a cell with a li-plated anode as overcharged at 4,2V! This state results in heat production inside the cell and further cathode and...

I would advise you guys not to use the word 'dendrites' as cause of the problem. Better to use 'Li-plating'. In case of a legal action Tesla would claim its relative good propagation protection for non-severe and even severe dendrite formation which happens randomly in only a limited amount of...

And how do you measure the amount of delithiation exactly?

No this happens immediately when i.e. delithiation is > ~ 60%.

The main disadvantage of NCA is that it degrades directly to a non-conducting rocksalt layer, while NCM degrades to a conducting spinel first. And on thermal runaway its the first to release oxygen. The advantage is that its cheaper, as long as you can handle its process from base material to...

This is my information too. And now they increased this threshold to around 40°C?

No, specially LMO spinel (LiMn2O4) cathodes show up with this problem. NCM has a far better stability than NCA!

Begin Of Life The IR you may calculate from his launch chart: First generation of Leaf had LMO cells afaik?

From the dissertation (what Alchemist forgot to post): A comparison with 2.0 A CCCV charging, depicted in Figure 52, reveals a considerably faster degradation for supercharging, although the total charging time differs only in the order of 10%. Hence, the high initial charging currents have...

And this is what customers should believe. From wk057s diagrams you can read the internal resistance being according to the datasheet. Please don't mix the graphite anode with SiC composite anodes! And the recovery from anode overhang (a common feature too) is another mechanism than Li-stripping!

Fast charging is a compromise. The problem in real charging is: Temperature. What do you do with a car that arrives at SuC station with a battery that has 50°F? Tesla encounters the problem by high initial current to heat up the cell by its (relatively high) internal resistance. But apparently...

The dissertation of Peter Keil, which was linked here already. https://mediatum.ub.tum.de/doc/1355829/file.pdf NCR18650A Please note that the graph is at 77°F, where Li-plating is the main driver for degradation at 3A! I don't know how was the thermal management at the SuC back in 2014, but...

From a study about battery aging, the capacity fade of a similar Panasonic NCA cell like the one used in your 85kWh packs: The charging method is CCCV at 77°F. 3A (1,1C) would need 95min for 0 to 100% SOC at 4,2V, but imho is comparable to SuC charging protocol from 2014 concerning...

No, when supercharging higher temperatures are better! The new thermal management is considering this by an increase of max temperature while supercharging. Of course storage temperature preferably should be low, thats true, but at the end thermal management will always be a compromise (in...

Exact! But i'm sure even if Li-plating is the main reason for the actions, we will never hear this word from official Tesla spokesmen!

Even if the bond wire fuse of one cell would be broken the resulting difference in brick voltage while SUC charging is max. 2,5mV, so within measurement accuracy. I considered the theory of extremely unbalanced bricks as well, but the reason (fire incidents) and the actions (reducing EOCV...