MotorTrend Checks in on EVs

[Joe (SoCal)]

Tesla's biggest problem is Elon Musk. He's such a polarizing personality he turns people off from even considering a Tesla. Also, the Tesla platforms are beginning to show their age, they're overdue for a refresh.

Agree 100%

That said the real gold in the Tesla empire is not the cars, but it's the flawless Super Charging network. Hell the one at the outlets in San Clemente went from 12 to 21 in a few days. and they are popping up everywhere.

[stromborg]

That is intriguing!
I can see specific places that might work, my district being one of them. It’s a little hilly but I think the drive train would still be OK. We’ve hydrants every 1500ft with pressures between 70 and 100psi so you hardly have to throttle up the engine (as long as you’re not trying to max out the gun on the truck). Most of our calls are smoke, CO and cats up a tree so the battery would serve most of our work and we still have the diesel engine for the few real fires. Does the electric motor power the pump? I wonder how responsive it would be (probably too responsive, it probably would need some kind of limiter)?

Next town over, wouldn’t work. Not a hydrant in site. They are the drafting and shuttle kings and needs lots or power.

Bill

The picture I put up was from Pierce, they claim "seamless" transitioning between the two modes. I haven't thought about the horsepower differential between pushing the rigs up hills and pumping. I'll have to call my favorite mechanic and ask. My guess is you could run the pump for a long time on battery alone.

[Canoeyawl]

A better example would be the standard three-prong electric outlet.

Yes, but which one?

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[Dan McCosh]

Yes, but which one?

DEB8F9A5-6484-4093-B621-9D7C9229BD24.jpg

The one you plug your toaster into.

[LeeG]

what about DC?

[Joe (SoCal)]

what about DC?

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[Figment]

... the Tesla platforms are beginning to show their age, they're overdue for a refresh.

I'd be interested to hear your thoughts on Randy Pobst's "experience an EV on real world terms" adventure he's been instagramming.
(he bought an old tesla 3, has been driving and troubleshooting and wrenching, talking about real world things like range-anxiety and parts availability)

[LeeG]

range anxiety
fuel gauge anxiety
status anxiety
flat tire anxiety
weather anxiety

people need to take a breath. It’s ok.

[Dan McCosh]

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Isn't that a Tesla tower in the background?

[AndyG]

range anxiety.

I've been thinking about this.

Living in the UK, post-Covid, now with no relatives nearby, and little need for long drives, I clocked up about 6k miles in the last 12 months. 95+% of those miles were undertaken on trips of under 50 miles.

So, I have no need to have any anxiety over range.

My plans for '23 include trips to the Lakes (150 miles) and then maybe showing my wife Dorset, in the summer. (She's a massive Thomas Hardy fan, and I've not been south of Birmingham in twenty years).

That trip, and only that trip, would require a charge halfway.

So, for me, there's no such thing as range anxiety. The only 'hassles' with an EV would be:

0/ Affordability.
1/ Can it tow the boat?
2/ Do I want to hang around a charging station for a few hours a very few times a year, compared to the current five-minute pee and petrol break?

Andy

[Joe (SoCal)]

Isn't that a Tesla tower in the background?

Yup

[LeeG]

I’d still want the turbo AWD Maverick pickup.

[Dikhaut]

Just saw on the news this evening that a Tesla burst into flames on the freeway for no apparent reason. The video showed the car burnt to a crisp. They said it took 6,000 gallons of water to put the fire out.


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[stromborg]

Lithium battery fires are very hard to put out. They are sensitive to heat to begin with and damaged cells tend to get hot, not much you can do but let it burn itself out.

[Joe (SoCal)]

Ahhh the one Tesla fire and people loose their minds, because internal COMBUSTION engine cars NEVER catch fire ever

[Breakaway]

Lithium battery fires are very hard to put out. They are sensitive to heat to begin with and damaged cells tend to get hot, not much you can do but let it burn itself out.

In NYC over 200 structure fires caused by lithium batteries last year. 10 deaths.
These were almost all e bike batteries.

There is talk of then being banned in public housing.

Kevin


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[LeeG]

In NYC over 200 structure fires caused by lithium batteries last year. 10 deaths.
These were almost all e bike batteries.

There is talk of then being banned in public housing.

Kevin


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bad bike batteries

[Garret]

Just saw on the news this evening that a Tesla burst into flames on the freeway for no apparent reason. The video showed the car burnt to a crisp. They said it took 6,000 gallons of water to put the fire out.


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I had a VW bus catch on fire & it got so hot the engine/transmission cases started burning (magnesium). After lots & lots of water, they had to bring in a foam truck from a nearby airport. So - it ain't just electric cars.

[bluedog225]

So much pointless travel. Marketed to the middle class as the good life. Dumb.

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[Katherine]

Ahhh the one Tesla fire and people loose their minds, because internal COMBUSTION engine cars NEVER catch fire ever

There have actually been several Tesla fires. Also an EV fire is much more intense and harder to put out than an ICE fire. Thermal runaway is no joke.

[Joe (SoCal)]

There have actually been several Tesla fires. Also an EV fire is much more intense and harder to put out than an ICE fire. Thermal runaway is no joke.

OMG, GASP SEVERAL How does that number compare with Internal COMBUSTION Engine fires ?

[LeeG]

So much pointless travel. Marketed to the middle class as the good life. Dumb.

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yeah and now 20 yrs later the hybrid version of that Toyota gets twice the mileage and more torque! That’s brilliant. What’s dumb is that 2002 Highlander was going into a market where fuel prices were being kept low to encourage consumption (growth!) just as we were about to wage war in the Middle East. People were talking about the need to update the Fed fuel tax then but fiscal conservatism was held captive by faux conservatives. And here we are 20 yrs later and the fed fuel tax is still 18.4 cents a gallon.
That’s dumb.

[Katherine]

OMG, GASP SEVERAL How does that number compare with Internal COMBUSTION Engine fires ?

Your response shows your ignorance as to why EV fires are so dangerous. It's not that they burn more or less then in numbers than an ICE, it's that they burn longer and MUCH hotter. Combine that with the fact that if the battery pack has been damaged, they can spontaneously light themselves on fire days after the damage was inflicted. Remember the cell phone and laptop batteries that spontaneously ignite? It's the same thing only bigger.

[Joe (SoCal)]

Your response shows your ignorance as to why EV fires are so dangerous. It's not that they burn more or less then in numbers than an ICE, it's that they burn longer and MUCH hotter. Combine that with the fact that if the battery pack has been damaged, they can spontaneously light themselves on fire days after the damage was inflicted. Remember the cell phone and laptop batteries that spontaneously ignite? It's the same thing only bigger.

Kat it was a joke relax, I'm not as great of a Tesla Fanboy as I'm a character of a Tesla Fanboy on here. I know the science regarding how LithIon burns. I also know its VERY common in cheep LithIon scooters and other minor appliances, but also VERY rare in EV's

FWIW I remember seeing the musician Harry Chapin's VW Rabbit engulfed in flames on the LIE with my dad and hearing the sad news that he had died.

I wonder if a ICE car with a full gas tank could have saved all the passengers and not explode like this Tesla Just saying

[Katherine]

Kat it was a joke relax, I'm not as great of a Tesla Fanboy as I'm a character of a Tesla Fanboy on here. I know the science regarding how LithIon burns. I also know its VERY common in cheep LithIon scooters and other minor appliances, but also VERY rare in EV's

FWIW I remember seeing the musician Harry Chapin's VW Rabbit engulfed in flames on the LIE with my dad and hearing the sad news that he had died.

I wonder if a ICE car with a full gas tank could have saved all the passengers and not explode like this Tesla Just saying

Probably not as well as not intentionally driving off a cliff.

Once the EV batteries start to burn, there is not much you can do except try and keep the fire from spreading. The storage facilities for EV batteries have thermal monitoring systems. If any battery starts to heat up, it gets dropped in a dunk tank to cool off.

[Paul Pless]

Kat it was a joke relax

dude

this line, in my vast experience, has never worked not one single time with katherine

not

one

single

time

most often it has the exact opposite effect

[stromborg]

It is actually pretty unusual for an ICE car to catch on fire in a crash (or an EV for that matter). Once you de-energize an ICE by disconnecting the battery it is pretty much inert, the problem with an EV is that the batteries can go off hours later. The answer seems to be don't crash your EV and don't buy cheap e-bikes.

The survival rate of MVIs has gone up considerably as airbags have become the norm. I went to a crash the other day that 20 years ago would have put the driver either into the ICU or a casket and she was sitting on the sidewalk talking on her cellphone.

[David G]

dude

this line, in my vast experience, has never worked not one single time with katherine

not

one

single

time

most often it has the exact opposite effect

Not surprising. And - as I'm sure you've also experienced - it's only a joke... if you make it CLEAR that you're joking. Backtracking, after the fact, is lame.

[Joe (SoCal)]

dude

this line, in my vast experience, has never worked not one single time with katherine

not

one

single

time

most often it has the exact opposite effect

Nor any of the 100’s of women in my life - It’s NEVER worked EVER But it’s still fun to blurt out from time to time. Kinda like pulling a hand grenade pin

[Dan McCosh]

It is actually pretty unusual for an ICE car to catch on fire in a crash (or an EV for that matter). Once you de-energize an ICE by disconnecting the battery it is pretty much inert, the problem with an EV is that the batteries can go off hours later. The answer seems to be don't crash your EV and don't buy cheap e-bikes.

The survival rate of MVIs has gone up considerably as airbags have become the norm. I went to a crash the other day that 20 years ago would have put the driver either into the ICU or a casket and she was sitting on the sidewalk talking on her cellphone.

The problem with lithium-ion batteries is that they can ignite for multiple reasons: physical damage (such as a crash), electronic failures, including both charging and discharging controls. The fires can be extinguished, but it is far more difficult than a typical gasoline fire. Cars spontaneously igniting and setting houses on far have been reported and have prompted recalls. Rescue workers do need special training.

[Nicholas Carey]

The problem with lithium-ion batteries is that they can ignite for multiple reasons: physical damage (such as a crash), electronic failures, including both charging and discharging controls. The fires can be extinguished, but it is far more difficult than a typical gasoline fire. Cars spontaneously igniting and setting houses on far have been reported and have prompted recalls. Rescue workers do need special training.

I was going to make pretty much that same comment.

Also, lithium-ion batteries have [approximately] the same energy density as, say, a 40% stick of dynamite (40% meaning 40% TNT/60% kaolin clay). They can also self-ignite/explode for other reasons than you've noted, including manufacturing defects — inclusions of minute impurities or crystals, for instance, or internal shorts. That sort of thing was a problem several years ago when people's phone's were catching fire in their pockets.

Other sources include dendrite (crystal) growth, which can occur from rapid charge/discharge cycles, or internal shorts, either a manufacturing defect, or from physical damage to the cell.

From the paper quoted below, here are some photomicrographs of batter defects than can lead to thermal runaway:

Figure 2. Manufacturing defects and quality control issues causing (a) a hole in the anode current collector and (b, c) impurities in the electrodes.



From the American Chemical Society's ACS Energy Letters, "Battery Hazards for Large Energy Storage Systems", published just last summer:

https://pubs.acs.org/doi/10.1021/acsenergylett.2c01400

Hazards Associated with Lithium-Ion Batteries

Hazards for Li-ion batteries can vary with the size and volume of the battery, since the tolerance of a single cell to a set of off-nominal conditions does not translate to a tolerance of the larger battery system to the same conditions. Li-ion batteries are prone to overheating, swelling, electrolyte leakage venting, fires, smoke, and explosions in worst-case scenarios involving thermal runaway. Failures associated with Li-ion batteries are described to be deflagration in nature. However, the gases produced as a result of a fire, smoke, and/or thermal runaway can accumulate to a combustible level in the installation location and cause an explosion (detonation). In general, the off-nominal conditions that can cause the occurrence of catastrophic events with Li-ion batteries can be categorized into electrical, mechanical, and environmental types. The most common electrical hazards are over-charge, over-discharge, and external and internal short circuits. Of the environmental hazards, off-nominal conditions such as temperatures beyond the manufacturer’s recommended range are those that are well understood. The influence of other environmental hazard causes, such as changes in altitudes, pressures, salt fog, floods, rain, etc., are not as well understood. Mechanical hazards such as those caused by vibration, shock, and impact are understood to a certain level, especially those encountered under transportation conditions.

Electrical Hazards

Over-charge of Li-ion cells and batteries can occur when they are charged at a very high rate or to a voltage that is above the manufacturer’s recommended specifications and limits for charging current are not appropriately designed into the system. Cathode destabilization, (13) lithium dendrite formation, (14) electrolyte decomposition, and the heat produced due to the high voltage or high charge rate can lead to catastrophic events. In addition, as cells and batteries age with storage and use, the individual cell’s electrochemical characteristics change, such as capacity and internal resistance, and in a battery configuration this causes deviations in characteristics between the cells in the battery. The deviations grow larger if no balancing of the cells/cell banks is provided, leading to excursions of voltage beyond safe limits, thus resulting in a catastrophic failure.
Studies have shown that a cell’s tolerance to an off-nominal condition such as an over-charge need not necessarily translate to a module- or battery-level tolerance to that same condition. (15) With the pouch format cells, due to the lack of internal protective devices like the current interrupt device (CID), the single cells go into thermal runaway with a fire and smoke when over-charged at medium rates such as 1 and 0.5 C. (16) It was also observed in the referenced study that pouch format cells were tolerant to a 0.3 C rate of over-charge current, but the same equivalent over-charge current caused cells in multicell series and/or parallel configurations to go into complete thermal runaway and fire.

An important factor to note for safe operation of batteries is the safety related to the use of appropriate chargers. Li-ion batteries have several types of metal oxides cathodes with a few different anode chemistries. In addition to the various combinations that can be obtained with the cathodes and anodes, electrolyte combinations can vary widely depending on the application load, cycle life and calendar life, and thermal and pressure environments. The chargers used should therefore be designed to accommodate the appropriate combination of electrodes and electrolyte. Traditionally, dedicated commercial chargers for low-energy applications of less than 60 Wh show a charge profile wherein the charge current starts falling even before the end-of-charge voltage (EOCV) is reached, as this helps to keep the temperatures low at the end of charge and also provides a margin for safety with respect to an over-voltage condition, which can be avoided with the gradual drop in charge current. (17,18) With large ESSs, all these factors need to be taken into consideration to prevent hazardous events due to an off-nominal over-charge/over-voltage condition.

Over-discharge is a process wherein the Li-ion cell is discharged below the manufacturer’s recommended end-of-discharge voltage. In a single cell, one cannot discharge the cell below 0 V; however, when one considers a module or battery design, it is possible to take any one cell into an “over-discharge into reversal” condition where the voltage of the cell/cells is driven into negative voltages and energy is still being extracted, leading to undesirable electrochemical changes in the cell. This can occur, as with a large ESS, when there is an imbalance in the cell’s electrochemical properties, such as capacity and internal resistance, described in simple terms as the “weak cell/cells”.

At voltages below the manufacturer’s recommended end-of-discharge value, dissolution of the copper current collector is initiated, and decomposition of electrolyte occurs. Under an extreme over-discharge condition, the dissolved copper ions deposit on the cathode, anode, and separator, and ultimately the system becomes an electrical wire instead of an electrochemical system, leading to a benign short circuit, making the cell or battery unusable. Subtle over-discharges, however, can lead to a catastrophic hazard without warning. (19) The bigger concern is the metallization of the dissolved copper ions and deposition of the metallic copper on the cathode, anode, and separator during the subsequent charge step. (19−22) This can lead to heating of the cell due to the effort that is required for the intercalation of lithium ions into the anode that has uneven copper deposition. At a certain point, lithium dendrites start forming on the surface of the copper layer, as the intercalation sites are covered with copper. This type of effect is more pronounced and can lead to a catastrophic thermal runaway in modules compared to that observed in single-cell batteries. In the absence of cell balancing in modules, a single or multiple over-discharges during the battery usage phase can lead to conditions in successive cycles that can subsequently lead to a catastrophic thermal runaway. The number of over-discharges that will lead to a catastrophic event depends on the extent of imbalance and over-discharge in the module. (23) With large ESSs, due to the significantly large number of cells required to build the battery system, cell-level voltage monitoring, cell balancing, and under-voltage cutoff at the module and battery pack levels are imperative.

External short circuit can be considered an electrical shock to the cell or battery. External short circuits can be high impedance or low impedance in nature. While the former occurs due to the lack of proper design to minimize the risk, the latter is more commonly observed and well known. Low-impedance or hard short circuits occur when the load imposed on a battery has a resistance that is equal to or less than the internal resistance of the article.

[continued]

[Nicholas Carey]

[continued from above]

The occurrence of high-impedance shorts can be reduced by designing the battery pack in an appropriate manner with the inclusion of electrical insulation materials between and around the cells, anodizing the battery container, and confirming that the wires are rated appropriately for the currents they need to conduct, that there are no sharp corners, that the wires are not bent in a way that would cause breakage, that the design is not conducive to chafing of the cables and wires, and that any exposed metal tabs and surfaces are well insulated. Low-impedance short circuits can be protected with the use of hard-blow and resettable fuses, poly switches, and thermal fuses. If fuses are used, then the reaction time of the fuse should be such that it protects the battery before any cell-level internal protective devices, such as the positive temperature coefficient (PTC), get activated, especially when the battery is a high-voltage/high-capacity type. When two fuses are used, then the rating of the two fuses should be different to ensure two-failure tolerance and should take into consideration the loads that will be encountered in the application in order to prevent a nuisance trip.

Protection against external short circuits has been incorporated into cell designs in various forms. The PTC was one of the earliest innovations that was included inside the 18650 format cylindrical cells and provides protection against a hard external short. Other cell formats, such as metal-can-prismatic cells, have included protective controls such as fusible links and bimetallic fuses that melt and disconnect, causing the cell to be permanently incapable of being charged or discharged. In the case of pouch format cells that do not have an internal protective device designed into the cell, external short circuit tests have shown to cause the burning of one of the tabs─thus protecting the cell from a catastrophic failure. The tab that is burned off is the one with the lower melting point and is different for various manufacturers (anode or cathode). (24)

The PTCs in cylindrical lithium-ion cells are doughnut-shaped devices that have a conductive polymer sandwiched between two stainless steel discs. Under high currents and high temperatures, these devices get activated due to the expansion of the polymer, which increases the resistance of the device, leading to a reduction in the current going in to or out of the cell. Protective devices such as PTCs have threshold voltage limitations like any electronic device. In the early days of Li-ion battery production, the applications required very low energy and power, and the devices required less than 30 Wh of energy. However, today, applications such as large ESSs are sized in the range of MWh to GWh. Due to the threshold voltage limitations in PTC devices, in off-nominal conditions, these PTCs do not protect as expected but rather become the cause of the hazard. (25,26) This typically leads to excessive charring of the header area of the cells, venting and leakage of electrolyte, and smoke. PTC threshold voltage limitations vary between cell manufacturers and also vary between different models from the same manufacturer. (25,26) In large ESSs, cells with internal protective devices should be proven by test to protect at the relevant level in the design configuration, and other levels of protection should be relied upon for safety control before a cell-level protective device is called in to provide protection.

Internal short circuits occur when the cathode and the anode physically touch each other inside a cell, leading to a short circuit. Internal short circuit hazards can be created in two different ways. Poor manufacturing and lack of quality control can lead to the formation of internal short circuits. (27,28)Figure 2 has examples of defects created and impurities introduced due to lack of quality control during the manufacturing process. Other ways internal shorts can be created are poor design, lack of or improper safety controls, and misuse in the field. The hazards discussed above, namely, over-charge, over-discharge, and external shorts, if not prevented by design, can create an internal short circuit that can lead to a catastrophic thermal runaway.

High-quality manufacturing and configuration control during the manufacturing process can significantly reduce the defects created, leading to a reduced risk of an internal short. Although there is no experimental proof that internal shorts due to manufacturing defects are a hazard, simulations of internal shorts using various methods have shown that Li-ion cells at 100% state of charge (SOC) experience a violent venting, fire, and thermal runaway. (29) Hence, cells used in the manufacturing of large ESSs should be screened and matched with a stringent protocol to prevent poor-quality cells from being introduced into the battery assembly process. Designing a battery with the required levels of safety control and using it within the manufacturer’s specification for current, voltage, and temperature reduces the risk of the formation of internal short circuits due to over-charge, over-discharge, and short circuits.

An important factor to be taken into consideration in large ESSs is the effect of arcing, which is encountered with systems higher than 50 V. (30,31) This voltage can be as low as 30 V in low-pressure environments. Hence, adequate protection against arcing and static electricity should be provided for the entire ESS, especially in the area of the connectors, to confirm that no sharp corners or pointed metal features are present that can cause an arc.

Thermal Hazards

High and low temperatures can lead to different unsafe conditions in Li-ion cells and batteries. High temperatures can lead to decomposition of the electrolyte and the solid-electrolyte interface (SEI) layer, destabilization of the cathode and anode that eventually lead to a violent venting, fire, and thermal runaway. Low temperatures increase the viscosity of the electrolyte in a Li-ion cell, reducing the mobility of the lithium ions in the electrolyte. The reduction in ionic conductivity causes the deposition of the ions as dendritic lithium metal due to the reduced ease of intercalation into the anode (Figure 3). This subsequently leads to increased internal cell temperatures, and in the presence of high temperatures due to increased internal resistance, growth of lithium metal dendrites, and the organic flammable electrolytes, the inevitable thermal runaway and fire occurs. Hazardous conditions due to low-temperature charging or operation can be mitigated in large ESS battery designs by including a sensing logic that determines the temperature of the battery and provides heat to the battery and cells until it reaches a value that would be safe for charge as recommended by the battery manufacturer. When heaters are used, the power to the heaters should be controlled to prevent uncontrolled heating due to heater failures.

Gradients in temperature in a battery configuration can also lead to an unsafe battery during its usage life. If battery configurations do not have a uniform thermal environment, then the capacity, internal resistance, and the voltage with respect to state-of-charge or depth-of-discharge of the cells in the battery will vary, and increased deviation will be observed during the life of the battery. Thermal gradients larger than 3 °C within a battery pack configuration can lead to deviations in the internal resistance of the cells with cycle and calendar life aging that can lead to significant variations and deviations in performance between the cells that can eventually lead to an unsafe condition of the battery. Thus, a thermal management system is imperative for large batteries, especially those that need to function continuously for several years and where extreme thermal environments will be encountered. The types of thermal management systems are discussed later.

Mechanical Hazards

Vibration, shock, and impact are examples of causes that are of the mechanical nature. Natural disasters such as seismic activity can lead to similar mechanically induced hazards. All three mechanical events induce faults such as disturbances to the internal construction of the cells, breakage of cell tab or intercell connections, contacts between the cathode and anode due to a distortion or tear of the separator, and the creation of other defects that can lead to an internal short circuit or high temperatures, both of which can lead to a catastrophic thermal runaway. Although this type of environmental hazard may be rare during field use (e.g., natural disasters), it can also be encountered during the device’s transportation to its final location, and hence the cells and system should be thoroughly inspected before and after installation of the entire system is completed.

[Joe (SoCal)]

Uuuuuuug

https://www.tesla-fire.com/


EVs catch fire far less often than gas-powered cars

[LeeG]

The problem with lithium-ion batteries is that they can ignite for multiple reasons: physical damage (such as a crash), electronic failures, including both charging and discharging controls. The fires can be extinguished, but it is far more difficult than a typical gasoline fire. Cars spontaneously igniting and setting houses on far have been reported and have prompted recalls. Rescue workers do need special training.

In moving my stuff around I had a plastic bin in a commercial space for a few years. Went to dig stuff out and and found a Mac lap top that was obviously heat damaged from a self destrucive event. I could have caused a heinous fire with that laptop.

[Dikhaut]

OMG, GASP SEVERAL How does that number compare with Internal COMBUSTION Engine fires ?

You mentioned people losing their minds over this. Besides you, who is losing their mind?


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