[NISFAN]

Originally Posted by SamS

Why do you make this stuff up? If you ever drove an AH3, you would understand that is not the behavior.

You have not knowledge or understanding of how the battery-control electronics work on these cars, yet you spout conclusions and comparisons to mobile phones? Why?

Eh? every time you run in EV mode, the battery is discharging, that CAN happen hundreds of times a day. So please explain how I am wrong on this?

I have worked with racing EV's so know some.....you don't need to drive a certain internal combustion engined car to know that you need fuel in the tank and the engine gets hot, etc. the same principles apply to everything in a particular technology field. Or perhaps BMW have found the holy grail?

[hermanz3]

Originally Posted by NISFAN

You are right, however a few things to consider....

Mobile phones only get charged discharged in quite a controlled manner. The current draw from a mobile is relatively low, and the charge is slow and controlled.

Li-Ion batteries lifespan are measured in charge cycles.

A Hybrid is capable of charging /discharging it's battery literally hundreds of times a day.

The charge /discharge rates in a Hybrid are significantly higher (and more harmful as a result)

The point about 'last the lifetime of the vehicle' is an interesting one. OEM's declare that as 10 years or 150,000 miles, however I noticed that they haven't given any reference to useful condition. A battery that charges to 1% could be described as 'lasted', but is absolutely useless.

Thank you for your reply.

Everything has its life ~ tires, brakes, gear box, leather seats, and your engine etc... so does the hybrid battery... oh and myself, too.

So...
I dont care if the battery will die/deteriorate
I dont care if tomorrow will introduce better technology

All I care is WHETHER I am enjoying my car NOW.

Answer to myself: Yes, I am enjoying my AH3 NOW.

[JS919]

Originally Posted by NISFAN

And in any case, given a winding mountain road, the AH3 only has 20 seconds of e-boost available, used up on one straight, even with some heavy braking for a corner it won't regain enough charge for another 20 second boost.

I'm not sure what kind of winding mountain roads you drive on? The ones I drive on there is no way I'll be able to leave my car full throttle for 20 seconds at a time! That would put me around 150 MPH starting the heavy braking. So maybe I could regenerate enough battery charge for the next straight?

[MotoEV]

Finally some drag strip numbers

[300hp]

Originally Posted by MotoEV

Finally some drag strip numbers

Great so the AH3 does the quarter in 13.5@106mph. Also note this guys is doing no fancy launch techniques and is wearing bad tires for this car. Add m sport with the 19s and a car and driver driver and you should be able to take some more time off of what this guy got. The fastest for the 335i right now is 13.5@105 with a car and driver driver and the staggered 19s.

[KroLeXz]

Wow impressive.

[Jparker82]

Nice..... My M sport Hybrid was called an unsporty Prius type car that will never compare to a 335. LMAO.... That's from a M3 owner in the other forum.

[jdong]

Originally Posted by NISFAN

You are right, however a few things to consider....

Mobile phones only get charged discharged in quite a controlled manner. The current draw from a mobile is relatively low, and the charge is slow and controlled.

Li-Ion batteries lifespan are measured in charge cycles.

A Hybrid is capable of charging /discharging it's battery literally hundreds of times a day.

The charge /discharge rates in a Hybrid are significantly higher (and more harmful as a result)

The point about 'last the lifetime of the vehicle' is an interesting one. OEM's declare that as 10 years or 150,000 miles, however I noticed that they haven't given any reference to useful condition. A battery that charges to 1% could be described as 'lasted', but is absolutely useless.

As someone with multiple years of experience doing hybrid electric drives for the military, and a MIT degree in electrical engineering and computer science, who is now ironically working on mobile consumer electronics... I have to say this is the most ridiculous bullshit I've ever heard regarding lithium ion energy storage systems and hybrid energy management.

Mobile phones have WORSE battery longevity because their charge-discharge cycles goes through virtually the entire battery capacity each day. Nobody makes a 20WHr battery so that they can only use 10WHr. They usually make a 20WHr pack and discharge to 19.5WHr or more. Furthermore, most mobile phone li-ion chargers are fairly dumb compared to hybrid vehicles. It generally involves applying a voltage limit or a current limit to the input of the battery pack. And that's considered "smart" charging.

In a hybrid vehicle, there's a number of very significant differences that lead to better longevity:

1. Only the surface 50% of the battery is used. The battery pack is a 1.3kWHr pack but only the top 675Whr is ever used. This prevents deep discharge, which takes a bigger toll on the battery pack.
2. The battery pack itself has a complicated battery management subsystem within the pack, monitoring individual cell stage-of-charge within the pack. Discharge and recharge are controlled in much finer granularity, preventing the over voltage or under voltage of a single cell from attempting to charge the entire pack at once (which is the most common cause of sudden degradation of a consumer electronic li-ion pack)
3. The vehicle does not cycle through the whole battery for shits and giggles. Most of the time, you're talking about losing 5% during a takeoff, then dumping it back into the battery the next time you brake. The only situation where the vehicle consistently uses your battery pack through the 50% charge is when you charge it up to 100% and then drive in pure EV mode for 2 miles. This is hard to sustain, as it takes a few miles of driving at a constant speed with the engine on in order to fully charge the pack. Then, after you discharge it, the battery cycles between 7% and 25% from that point forward. You'd have to drive laps again to charge up the battery fully in order to start discharging it again. At which point you're talking about having to cover thousands of miles of distance to get those "hundreds" of charge cycles that you're speaking of.

Furthermore, the longevity of battery packs in hybrid cars is widely proven already. Priuses have been on the road for hundreds of thousands of miles per driver, and Toyota has not documented their batteries degrading to the point that it affects fuel economy or warranted replacement. Granted those are NiMH's, but similar principles apply. There's some recent talk about the Nissan Leaf's pack lasting a lot shorter than it should, but there's a number of serious design flaws in the cells manufactured by NEC — in fact Nissan switched to Hitachi for the 2013 MY.

There's no evidence to support your claim that the lithium (iron phosphate, by the way), battery pack in the AH3 is doomed. Nor is it at all correct to compare a cell phone battery to a hybrid car battery. Nor are your characterizations of the behaviors of EITHER battery use case correct.


I would go on to address your "1% charge is considered charged" point, but that argument is so absurd it's not even worth my time to write anything up for it.


Bottom line is, you, as a non AH3 driver, have made a lot of assumptions about how the car behaves that are not correct. You can design a hybrid that breaks in 6 months. You can design one where the battery will outlast most other components on the car. Also, this is not a racing EV. This is a production hybrid electric vehicle. EV racing represents a totally different set of end goals (e.g. performance over longevity).

[jdong]

Originally Posted by Jonas

I'm not sure what kind of winding mountain roads you drive on? The ones I drive on there is no way I'll be able to leave my car full throttle for 20 seconds at a time! That would put me around 150 MPH starting the heavy braking. So maybe I could regenerate enough battery charge for the next straight?

Exactly. The car keeps plenty of residual charge to give you several seconds of eBoost in the worst case scenario, in Comfort mode. And that will easily rocket you to felony speeding in the US before the battery runs out.


Furthermore, if you place the vehicle in Sport mode, it begins more aggressively load-shifting the engine to divert more "unused" engine power towards charging the battery (at the cost of fuel economy), which maintains more energy reserves for eBOOST.

Bottom line is, in the real world, it's very unlikely that you find yourself in a situation where you need eBOOST and there's insufficient battery charge to provide it.


P.S. I'd also like to mention that, I think the AH3 is somewhat disadvantaged compared to a 335i for a magazine 0-60 test. The 335i lends itself to a lot of launch techniques that the AH3's hybrid transmission likely won't let you do. This can cost you a couple valuable fractions of a second, which make or break your 0-60 run. The AH3 is a real world car. If you're looking to track a car, this is probably not the car for you.

[MCoupeInsanity]

Originally Posted by Roki_014

You 've seen it in videos i did it in person and didnt feel any difference at all, and my dealer said the same thing, that they didnt feel any difference, and the car just behaves weird up to like 3500 rpm cuz of the electric motor, i am not saying that the car is bad, i feel like the technology is still not there

To be fair, "the technology" is there just fine -- BMW is not there with the technology yet. Same with the Automatic Start/Stop (never has ASS been a more appropriate acronym) on the F30. Toyota has been making hybrids for far longer, and the result is clear: the same tech in a Prius or a Camry Hybrid or a Lexus Hybrid is far more refined than in BMW's offerings.

[MCoupeInsanity]

Originally Posted by jdong

As someone with multiple years of experience doing hybrid electric drives for the military, and a MIT degree in electrical engineering and computer science, who is now ironically working on mobile consumer electronics... I have to say this is the most ridiculous bullshit I've ever heard regarding lithium ion energy storage systems and hybrid energy management.

LULZPWND

[Elk]

Originally Posted by jdong

As someone with multiple years of experience doing hybrid electric drives for the military, and a MIT degree in electrical engineering and computer science . . .

What is the typical torque curve of the electric motor as used in a hybrid configuration?

Is the typical electric motor management set to produce 100% torque at 0 RPM and then taper off as the engine reaches high enough RPM to generate enough torque to take over?

I assume this is how it is done in the BMW hybrid as the total torque and horsepower of the 3 series hybrid is less than the sum of the motor and the engine.

[jdong]

Ah, very good questions, Elk. Basically, the answer to your question is two-fold. "Why isn't the combined power the sum?" has a different answer than "What's the hybrid control strategy of the AH3?". I'll answer them in that order:

I assume this is how it is done in the BMW hybrid as the total torque and horsepower of the 3 series hybrid is less than the sum of the motor and the engine.

So this is likely due to a combination of marketing and the characteristics of a permanent magnet synchronous machine (the type of motor in the AH3). A PMSM makes "full" torque starting from 0RPM. However, remember that a motor is also a generator. As the motor speeds up, the permanent magnets cause it to produce more and more "back-EMF", which is the voltage measured across the motor. When that voltage reaches 317V, then the motor would stop accelerating, because now the motor cancels out the bus voltage. You can design the motor to either have a wide or narrow "constant torque operation range", but that comes with tradeoffs. The alternative is an approach known as "field weakening". Field weakening, in plain English, is diverting some of the electricity sent into the motor to produce a magnetic field that "cancels out" the permanent magnet's field. In this way, you in effect counteract the back-voltage of the motor, allowing it to reach higher speeds.

The typical control algorithm used for field weakening produces what's known as a "constant power speed range", which means past a certain speed, you linearly reduce the torque, which will cause your power to hold constant. This makes for a machine that's easier to control from the hybrid management's perspective (e.g. if you have a motor whose power output changes from 30HP to 80HP to 30HP over the course of 500RPM, that's a nightmare to combine with a slow-to-respond gas engine without resulting in a jerky clunky ride). So the power curve of a motor tends to be linear from 0 up to some speed (let's say 1000RPM), then it holds "constant" from 1000RPM to the max operating speed of the motor, which may be as high as redline in this case. But of course in the real world, "hold constant" is a pipe dream. As the motor gets faster, minor errors and delays in the motor controller's control algorithm lead to bigger and bigger losses in power. So in reality, power will slowly taper off even within this "constant power" region.

So, while the motor may be capable of a higher "peak" power output, it likely is held a bit below its potential so that it provides consistent performance across a wider speed range. Furthermore, as our skeptic above had alluded to, which does have some truth, motors generate a lot of heat. While the AH3's motor might be capable of 55HP output most of the time, on a hot summer day the cooling system may not be able to keep up, and the power would have to be limited. Given that BMW has a tradition of underrating the dyno performance of their cars, I bet that BMW would want the numbers they advertise to be easily reproducible or beaten by someone with a dyno. So while it may do peaks of 55HP, if you keep the vehicle in eBOOST it's very likely the overall contribution of the electric motor will taper down to around that 32HP mark.

Originally Posted by Elk

What is the typical torque curve of the electric motor as used in a hybrid configuration?

Is the typical electric motor management set to produce 100% torque at 0 RPM and then taper off as the engine reaches high enough RPM to generate enough torque to take over?

I assume this is how it is done in the BMW hybrid as the total torque and horsepower of the 3 series hybrid is less than the sum of the motor and the engine.

So, this actually has more to do with efficiency.

In a pure hybrid configuration, the golden rule to remember is:
Battery power is NOT free. If you waste it, you either lose it until the next time the user brakes for a while, or you have to purposely sap power from the engine to recharge, making it less efficient.

So, assuming your hybrid is geared for efficiency (e.g. our Comfort and ECO PRO modes), you only want to involve the motor (either in generation or assist) when you are pretty damn confident that if you didn't, the gas engine would be less efficient, or energy would be totally wasted. Good examples of these circumstances include:

• Accelerating from a standstill. Your gas engine is not terribly efficient when forced to drive your car from 0MPH to 10MPH. This forces your car from an unusually low RPM up to a fairly high RPM. After all, you don't want your car feeling like it's in Eco Pro mode, shifting up at 1500RPM all the time.
• Sudden accelerator inputs. The assumption here is that your engine is both slow and inefficient to respond to sudden changes in your acceleration. Thus, when accelerating suddenly, the car will use the motor to assist in the acceleration as to take load off your engine.
• Opportunistic parasitism. If you already have the engine revved up to an inefficient operating point (like say 3000RPM from angrily passing the Prius next to you), the motor will sap some power from the engine to recharge the battery pack a bit if needed, up to 85%. The idea here is you might as well steal some power when it has the least impact on efficiency.
• Braking. Any energy that the motor can't recover when braking is for sure going to turn into hot brake dust. Recover everything you can while braking.

Now, the efficiency improvement in those circumstances are as certain as the laws of physics. It's hard to think of a case where using the motor in the above ways would lead to decreasing efficiency.

Now, with that said, there's cases where your car will take a gamble and bet that probably it's improving your efficiency. These situations include:

• Excess battery charge is spent generously. Typically the car attempts to slowly charge the battery to 85% and then hold it there. Any energy recovered beyond 85% is considered "excess". For example, if you're at 85%, and then you coast down a hill to get to 95%, you will notice that as you begin to accelerate again, your battery will rapidly drain back to 85%, then hold there again. The car just used 10% of your juice to temporarily boost your fuel efficiency. The reason for keeping this 15% buffer is you want to have some place to store regen energy if you happen to start going down a hill or need to brake to get off the highway.
• When going up a small hill, Assist tends to kick on for a little bit of time (maybe just a few percent of the battery) based on the assumption that you'll probably be going down that hill again. I've only seen it go from 85% to 80% doing this in the worst scenario. Usually only dropping 2% or so and then recovering it back.
• All-electric driving at low speeds. The idea here is that at low speeds you're far more likely to be dipping below the engine's efficient operating points, and constantly changing your acceleration. So it might be better off below a certain speed to just let you do all-electric driving.
• In Europe, the car will use the nav system's terrain info to predict hills ahead. I don't think the North American maps support this.
• The car is actually supposed to use traffic congestion & speed limit info to plan its battery usage too. I don't know if that's actually implemented.

So, that's a pretty decent summary of how the AH3 uses the hybrid system to boost your efficiency. While I'm on the topic, there's two other things I wanted to say:

(1) How does ECO PRO and SPORT mode change things? ECO PRO mainly just allows the engine to shut off while coasting up to 100mph (rather than 35mph), and all-electric driving up to 47mph. The car doesn't allow that in COMFORT mode mainly because it would cause an un-BMW-like hiccup in power delivery as the engine kicks back on. Below 35mph, the electric motor has enough muscle to distract you while the engine starts up and takes over. In SPORT mode, the car never shuts off the engine unless fully stopped. It also uses eAssist very generously while accelerating, to exaggerate the responsiveness of the accelerator pedal. It also forces the car to aggressively charge the battery up to 85%, in preparation for spirited eBOOST driving.

(2) A lot of people get into my car while it's cruising on the highway, look at that Prius-like power diagram and say "uhh.. the motor isn't doing anything". Of course it isn't. If you're just cruising along, it's more efficient to just use the engine rather than generating some power, using it up via the motor, then increasing engine output to charge the battery again, etc etc etc.

(3) Some ask "why not put a bigger battery in?". Well, without adding a plug to the car, that's really not going to change things. The only "free" energy that you get comes from braking and going downhill. And the energy you can recover from braking is honestly limited by the motor size (50HP is not a lot of braking force, and you don't wanna be THAT guy braking 2 blocks from the red light). And there's very few cases where you brake downhill for long enough that you fill up the battery all the way. And if you want to make the motor / battery bigger, you're probably going to have to scale up most of the electronics to handle the higher peak currents and the cooling system to handle the additional heat. At that point, the car is even LESS cost effective than it already is. You might as well put a plug on the car and advertise carpool lane access. And I'm *sure* BMW has a plugin hybrid in the works

[NISFAN]

Originally Posted by jdong

As someone with multiple years of experience doing hybrid electric drives for the military, and a MIT degree in electrical engineering and computer science, who is now ironically working on mobile consumer electronics... I have to say this is the most ridiculous bullshit I've ever heard regarding lithium ion energy storage systems and hybrid energy management.

Mobile phones have WORSE battery longevity because their charge-discharge cycles goes through virtually the entire battery capacity each day. Nobody makes a 20WHr battery so that they can only use 10WHr. They usually make a 20WHr pack and discharge to 19.5WHr or more. Furthermore, most mobile phone li-ion chargers are fairly dumb compared to hybrid vehicles. It generally involves applying a voltage limit or a current limit to the input of the battery pack. And that's considered "smart" charging.

In a hybrid vehicle, there's a number of very significant differences that lead to better longevity:

1. Only the surface 50% of the battery is used. The battery pack is a 1.3kWHr pack but only the top 675Whr is ever used. This prevents deep discharge, which takes a bigger toll on the battery pack.
2. The battery pack itself has a complicated battery management subsystem within the pack, monitoring individual cell stage-of-charge within the pack. Discharge and recharge are controlled in much finer granularity, preventing the over voltage or under voltage of a single cell from attempting to charge the entire pack at once (which is the most common cause of sudden degradation of a consumer electronic li-ion pack)
3. The vehicle does not cycle through the whole battery for shits and giggles. Most of the time, you're talking about losing 5% during a takeoff, then dumping it back into the battery the next time you brake. The only situation where the vehicle consistently uses your battery pack through the 50% charge is when you charge it up to 100% and then drive in pure EV mode for 2 miles. This is hard to sustain, as it takes a few miles of driving at a constant speed with the engine on in order to fully charge the pack. Then, after you discharge it, the battery cycles between 7% and 25% from that point forward. You'd have to drive laps again to charge up the battery fully in order to start discharging it again. At which point you're talking about having to cover thousands of miles of distance to get those "hundreds" of charge cycles that you're speaking of.

Furthermore, the longevity of battery packs in hybrid cars is widely proven already. Priuses have been on the road for hundreds of thousands of miles per driver, and Toyota has not documented their batteries degrading to the point that it affects fuel economy or warranted replacement. Granted those are NiMH's, but similar principles apply. There's some recent talk about the Nissan Leaf's pack lasting a lot shorter than it should, but there's a number of serious design flaws in the cells manufactured by NEC — in fact Nissan switched to Hitachi for the 2013 MY.

There's no evidence to support your claim that the lithium (iron phosphate, by the way), battery pack in the AH3 is doomed. Nor is it at all correct to compare a cell phone battery to a hybrid car battery. Nor are your characterizations of the behaviors of EITHER battery use case correct.


I would go on to address your "1% charge is considered charged" point, but that argument is so absurd it's not even worth my time to write anything up for it.


Bottom line is, you, as a non AH3 driver, have made a lot of assumptions about how the car behaves that are not correct. You can design a hybrid that breaks in 6 months. You can design one where the battery will outlast most other components on the car. Also, this is not a racing EV. This is a production hybrid electric vehicle. EV racing represents a totally different set of end goals (e.g. performance over longevity).

You clearly know the subject, but still answer in a blinkered pro AH manner.

Discharging by 5% and re-charging is as bad as discharging by 50% and recharging (thermal and some other factors ignored). The degradation per KW/hr power supplied will be roughly the same.

So delivering 100Kw/hr of energy, whether you do that in 1000 cycles of discharge/recharge 5% or 100 cycles of 50% will cause roughly the same degradation. *Degradation by ion loss and corrosion.

I'm not sure if the use of the term 'Top 675W/hr' is some kind of deception to those that don't know better? or just your language to differentiate which battery state you are talking about? We know that when you discharged a mass of cells, energy passes through the entire system as a whole. It is not a case of some cells doing the work, whilst others wait their turn. They are all involved, cells self stabilise when one is spiked.

My point about mobile phone chargers, is one critical factor in Li-Ion battery life, is thermal exposure. Mobile phones have a low draw, avoiding heat, they also have a low charge rate, again avoiding heat.

In a hybrid, the battery is under much higher demand, often called to supply in the AH3's case 55 mechanical horsepower worth of energy instantaneously (more in terms of electrical horsepower due to the losses). Yes limited to x seconds, but the reaction in the battery to this is rapid heat build up. When racing EV's, heat management is the single biggest issue with the batteries. Boeing know a thing or two about overheated batteries.

You mentioned the Prius, a car using a hybrid solution in order to extract maximum efficiency from an ICE. Not due to the wonders of hybrid as such, more to keep a petrol engine in it's peak efficiency window. Not exactly that reliant on it's battery system (pre plug in Prius), in fact many Prius with dead batteries have been driven to the local Toyota dealership. And Oh yes there have been many dead batteries.

You also quote Toyota as a reliable source as to long term fuel efficiency drop off. Great I'll ask Coca-cola who makes the best cola drink.

[jdong]

Shallow discharges are NOT the same load to a li-ion pack as deep discharges. The deeper you discharge a lithium ion pack, the more likely you are to damage the cells. Typical lithium cell ratings for consumer (e.g. Mobile phone) grade lithium ion cells are along the lines of:
300 charge cycles with 80% depth of discharge
500 charge cycles with 50% depth of discharge
1000 charge cycles with 30% depth of discharge.

EDIT: Obviously you're not going to believe me, because I'm a paid BMW spokesperson for the ActiveHybrid 3. Here's an independent article about how depth of discharge affects li-ion battery life. The same principle applies for hybrid cars: http://batteryuniversity.com/learn/a...ased_batteries

Of course, those are cheap mass produced consumer grade battery packs. Automotive li-ion cells last a lot longer, especially the LiFePO4 chemistry in the AH3's pack.

And your mobile phone battery is not cooled by a 5 kW compressor and coolant circuit. Heat is monitored and regulated, and the vehicle will provide less and less hybrid assistance when the temperature is not within an ideal range. The first minute or so of driving on a hot summer day, the car won't provide any hybrid assist.

And I don't know why I should treat you as a more reliable source regarding Toyota fleet reliability compared to the manufacturer. Could they be making things up? Sure. But I certainly do not see widespread reports of Priuses with flat NIMH packs.

[jdong]

And oh yeah, perhaps you should read the NTSB report. I'm an aircraft accident investigation hobbyist too. The Dreamliner's battery did not catch fire because it overheated. It caught fire because poor design and manufacturing caused an internal cell to cell short due to vibration, which lead to thermal runaway because the cells were spaced too closely together such that a burning cell would ignite its neighbors.

[Elk]

Originally Posted by jdong

Basically, the answer to your question is two-fold. "Why isn't the combined power the sum?" has a different answer than "What's the hybrid control strategy of the AH3?". I'll answer them in that order . . .

Thank you! Fascinating.

I also enjoy the phrase "Opportunistic parasitism."

[btbossman]

Awesome thread!

[NISFAN]

Originally Posted by jdong

Shallow discharges are NOT the same load to a li-ion pack as deep discharges. The deeper you discharge a lithium ion pack, the more likely you are to damage the cells. Typical lithium cell ratings for consumer (e.g. Mobile phone) grade lithium ion cells are along the lines of:
300 charge cycles with 80% depth of discharge
500 charge cycles with 50% depth of discharge
1000 charge cycles with 30% depth of discharge.

EDIT: Obviously you're not going to believe me, because I'm a paid BMW spokesperson for the ActiveHybrid 3. Here's an independent article about how depth of discharge affects li-ion battery life. The same principle applies for hybrid cars: http://batteryuniversity.com/learn/a...ased_batteries

Thanks for the link, I have also read some research on Hybrid battery degradation, but of course it is not always clear how lab results relate to real use.

Your table is roughly what I was talking about in terms of degradation being linked to 'power supplied'. As follows:

300 charge cycles with 80% depth of discharge =300 x 0.8 = 240 units of energy supplied
500 charge cycles with 50% depth of discharge = 500 x 0.5 = 250 units of energy supplied
1000 charge cycles with 30% depth of discharge = 1000 x 0.3 = 300 units of energy supplied

Roughly 20% difference, probably more than I was expecting, but do you not think a hybrid that is constantly (even if we are talking generally 5%, but occasional 30-50%) re-charging, will be degrading the pack? I guess time will tell.

Prius is a different matter, as I said, it was designed to get maximum efficiency from the ICE (by keeping an Atkinson cycle petrol engine under load constantly), so although been around some time, is not really comparable with something like an AH3.

[NISFAN]

Originally Posted by jdong

And oh yeah, perhaps you should read the NTSB report. I'm an aircraft accident investigation hobbyist too. The Dreamliner's battery did not catch fire because it overheated. It caught fire because poor design and manufacturing caused an internal cell to cell short due to vibration, which lead to thermal runaway because the cells were spaced too closely together such that a burning cell would ignite its neighbors.

This is an equally worrying factor for an AH owner too ....No?

I'm pretty sure more research went into meeting tougher Aerospace certification than Automotive.

Motoczysz had a bike destroyed by battery fire, the fire marshals were unable to put it out. Also caused by a cell that went short circuit.

[Jparker82]

Originally Posted by SamS

Your guess is wrong.

eBoost: http://www.f30post.com/forums/showthread.php?t=791178

+1

[Jparker82]

Originally Posted by Roki_014

You 've seen it in videos i did it in person and didnt feel any difference at all, and my dealer said the same thing, that they didnt feel any difference, and the car just behaves weird up to like 3500 rpm cuz of the electric motor, i am not saying that the car is bad, i feel like the technology is still not there

That is so far from true. Can't even tell there is a hybrid system in the car. The only weird thing is how much power is has off the line. The tech is so far above every other car line. You would thought that Toyota tech would of been the best. BUT now they are teaming up with BMW for this tech.

AH3 hate everywhere. LOL..... AH3 is the fastest 3 series ever made Period. Not to include M.