F8x Li-ion battery costs HOW MUCH ?

[Needsdecaf]

Originally Posted by JoeFromPA

I'm going to go the other way. I understand the battery has lots of integrated electronics. Awesome.

If your car couldn't run off a regular lead-acid battery, then it would definitely have an issue being jumped by a lead-acid battery (since the other power doesn't disconnect the moment the car fires).

Batteries inherently have to operate under a very wide range of outputs due to variances in charge state, temperature, and demand. They need to be able to output a certain minimum power; they DO NOT need max-power all the time nor when starting the car. Which is why a car with a half-charged battery in 0 degree weather can sometimes still start.

The more I think through this, the more I'm of the mindset that "in a pinch I could run this thing off a 12-volt lead-acid battery and it'd manage itself fine. Unless I see a statement from BMW telling me otherwise, or that the car can only be run on a LI-Ion battery, then I'm assuming it can use different power sources.

Joe

P.s. I could totally be wrong. I'm just using logic, my understanding of electrical systems and batteries, and the lack of any contrary statement by BMW to this affect.

Consider this: MANY shops around the country/world have "shop batteries" sitting around for use in starting/charging situations. They are usually honking big lead-acid batteries. I see no warning anywhere from BMW to only use LI batteries when starting or operating this car...?

Joe, I respect you (great name!) and you've given some valuable posts on this forum. What you say makes sense, and is logical and well thought out. But it is wrong.

The problem lies not only within the fact that it's Lithium Ion, but the electronic functions contained within the battery. You casually brushed that aside, but you really shouldn't. You asked for a statement from BMW telling you otherwise, and I gave it to you. Here it is:

http://f80.bimmerpost.com/forums/att...5&d=1406475520


Read chapter 6 of the complete vehicle technical guide linked above. Based on what I am reading, it seems as if the car's alternator and charging circuits are designed for the Li battery. I won't re type the whole thing but the Li battery can take charge faster, among other things. I think there would be issues with a lead acid battery. The charge rates would probably destroy the lead acid battery and while that might not be the end of the world, the voltage rates could start to get wonky. Which can be a problem.

But more crucially is the circuitry in the battery, which the car would likely not do well without. A standard battery wouldn't have this circuitry, and the document states that the circuits in the battery are responsible for FIFTEEN different functions related to the car's electrical system, such as diagnostics, wake up, voltage monitoring, state of charge, etc. Most crucially are the communications with the LIN Data bus, the diagnostics functions, and the Wake up functions. I think that without these circuits in place, the car's network is going to throw a shit fit at too many missing pieces of data when you go to start it, you would get a bunch of errors, and the car probably wouldn't start.

I'm an engineer, but not an electrical one, so I couldn't tell you exactly how all of this works. But I have been around and messing around with cars with central data busses long enough to know that some of these functions are trivial and some are critical. And when the critical ones like those described above get confused, all sorts of issues crop up.

Now, since the F30 doesn't use this type of battery, you MIGHT be able to use a standard lead acid battery suitable for an F30 by using the Intelligent Battery Sensor that is installed along with the F30 battery. This is a stand alone microprocessor that is bolted onto the negative terminal and assumes the function of the circuits designed into the F80's Lithium Ion battery. IF, and I'm making an assumption here, the signals sent by the processor were similar to those sent by the circuits integrated into the F80's battery, you might fool the computer into thinking all was well.

However, in reading the differences in voltages provided by the Lithium Ion battery, and in reading all the functions of the IBS (found here http://www.bimmerscan.com/bmw-intell...ry-sensor-ibs/), and how often those values are updated and read, I think you'd run into issues with the Lead Acid battery quickly. Because the Lithium Ion battery is designed to take charge more quickly than the Lead Acid battery, the alternator is programmed to feed the battery charge accordingly. If you start to juice the Lead Acid battery at a rate it is not capable of accepting, I'm not exactly sure what's going to happen, but I would think you would overhead the lead acid battery. Someone more familiar with electronics and batteries especially can weigh in and tell me what would happen if you exceeded the charging rate of a battery.

Out of curiosity, the listed number of charging cycles for each is 350 for the lead acid vs. 5000 for the Li battery It also states that the service life is expected to be twice as long as a lead acid battery.

[huatian]

Originally Posted by Needsdecaf

Joe, I respect you (great name!) and you've given some valuable posts on this forum. What you say makes sense, and is logical and well thought out.

But it is wrong.

The problem lies not within the fact that it's Lithium Ion. But the electronic functions contained within the battery. You casually brushed that aside, but you really shouldn't. You asked for a statement from BMW telling you otherwise, and I gave it to you. Here it is:

http://f80.bimmerpost.com/forums/att...5&d=1406475520


Read chapter 6 of the complete vehicle technical guide linked above. Based on what I am reading, it seems as if the car's alternator and charging circuits are designed for the Li battery. I won't re type the whole thing but the Li battery can take charge faster, among other things. I think there would be issues with a lead acid battery. The charge rates would probably destroy the lead acid battery and while that might not be the end of the world, the voltage rates could start to get wonky. Which can be a problem.

But more crucially is the circuitry in the battery, which the car would likely not do well without. A standard battery wouldn't have this circuitry, and the document states that the circuits in the battery are responsible for FIFTEEN different functions related to the car's electrical system, such as diagnostics, wake up, voltage monitoring, state of charge, etc. Most crucially are the communications with the LIN Data bus, the diagnostics functions, and the Wake up functions. I think that without these circuits in place, the car's network is going to throw a shit fit at too many missing pieces of data when you go to start it, you would get a bunch of errors, and the car probably wouldn't start.

I'm an engineer, but not an electrical one, so I couldn't tell you exactly how all of this works. But I have been around and messing around with cars with central data busses long enough to know that some of these functions are trivial and some are critical. And when the critical ones like those described above get confused, all sorts of issues crop up.

Out of curiosity, the listed number of charging cycles for each is 350 for the lead acid vs. 5000 for the Li battery It also states that the service life is expected to be twice as long as a lead acid battery.

There in lies the issue, not the output of the battery - You can use any 12v battery with the appropriate amp power to turn over the engine and start the car. It's the charging rate that's the real issue. Either the circuits are part of the battery as a system, or they are separate. If their separate, then there is a high probability a standard wet cell will be fine as the charging rate will be similar to other BMW without Li-ION batteries and a wet cell won't be a problem. Pull out a volt meter and check the amperage per unit of time if you want to know for sure. Fast way to do it without lots of gear:

- Fluke meter set to amps (used correctly)
- Start the car, measure the amps in some unit of time.
- Best way to do it, good data recording meter - like fluke 289, let it data gather
for some time, review the data for some time period and get the charge rate. Then you'll know if the charing circuits are in the battery or part of the electrical system as a whole. I got money on its's part of the battery.

[Needsdecaf]

Originally Posted by huatian

There in lies the issue, not the output of the battery - You can use any 12v battery with the appropriate amp power to turn over the engine and start the car. It's the charging rate that's the real issue. Either the circuits are part of the battery as a system, or they are separate. If their separate, then there is a high probability a standard wet cell will be fine as the charging rate will be similar to other BMW without Li-ION batteries and a wet cell won't be a problem. Pull out a volt meter and check the amperage per unit of time if you want to know for sure. Fast way to do it without lots of gear:

- Fluke meter set to amps (used correctly)
- Start the car, measure the amps in some unit of time.
- Best way to do it, good data recording meter - like fluke 289, let it data gather
for some time, review the data for some time period and get the charge rate. Then you'll know if the charing circuits are in the battery or part of the electrical system as a whole. I got money on its's part of the battery.

Read my link above. The standard F30 uses an Intelligent Battery Sensor strapped to the normal battery to provide data on amps, volts, temp, etc. this circuitry is built into the F80's battery. So you are right, it's not in the car, it's in the battery.

[CurbBender'90]

The bigger question is can this battery be used in the E92 for the future?

[derpimpkar]

The battery is expensive, no question. It might be good to know for making a decision up front but I don't think it would have changed any minds. The F8x is an envelope car. You're going to sacrifice cost for performance.

veyron tires are ~$40k a set. the wheels are ~$70k a set have to be changed every other tire set. I wonder how much CCB maintenance will be. we're in a different market, that's all.

[huatian]

Originally Posted by BMW_Boy7

The bigger question is can this battery be used in the E92 for the future?

if you take the inputs and feed into li-ion charging circuit yes.


+ |-------------| ------------+
| Li-ION | |
| Charging | Battery
| Circuit | |
_ | ------------|------------- -

[JoeFromPA]

Originally Posted by Needsdecaf

Read my link above. The standard F30 uses an Intelligent Battery Sensor strapped to the normal battery to provide data on amps, volts, temp, etc. this circuitry is built into the F80's battery. So you are right, it's not in the car, it's in the battery.

Might be worthwhile to look at section 6.1.3 of your link. Pretty much states a lead acid/AGM battery would work in the m3/m4.

To your point, both the F30 battery with the IBS and the F80 have an extensive on battery or in-battery sensor. But it's ALL about battery sensing - none of it is about the circuitry in the battery is integral to vehicle operation, just about assessment of whether the battery is safe to use.

Now, thanks to you link (lol), I'm 75% confident in my initial assessment that a lead acid/AGM battery would work in an f8x vehicle and even more strongly feel that it would have been a gross dis-service if that technical bulletin specifically stated that AGM/Lead-Acid IS appropriate for ALL vehicles and yet they really meant they would be excluded from the f8x.

[GrussGott]

Originally Posted by Needsdecaf

Read my link above. The standard F30 uses an Intelligent Battery Sensor strapped to the normal battery to provide data on amps, volts, temp, etc. this circuitry is built into the F80's battery. So you are right, it's not in the car, it's in the battery.

Interesting - I wonder if this is similar technology to Qualcomm's Quick Charge 2.0 technology on my phone? If so I love it - I can get a 50-60% charge in 15 minutes and full charge in an hour.

If this battery does that too I'm all for it.

[Needsdecaf]

Originally Posted by JoeFromPA

Might be worthwhile to look at section 6.1.3 of your link. Pretty much states a lead acid/AGM battery would work in the m3/m4.

To your point, both the F30 battery with the IBS and the F80 have an extensive on battery or in-battery sensor. But it's ALL about battery sensing - none of it is about the circuitry in the battery is integral to vehicle operation, just about assessment of whether the battery is safe to use.

Now, thanks to you link (lol), I'm 75% confident in my initial assessment that a lead acid/AGM battery would work in an f8x vehicle and even more strongly feel that it would have been a gross dis-service if that technical bulletin specifically stated that AGM/Lead-Acid IS appropriate for ALL vehicles and yet they really meant they would be excluded from the f8x.

Yeah, I read that. I'd love for you to explain how it states your case? The nominal voltage is not even the same.....??

As far as the "assessment that the battery is safe to use", it's a little more complicated than that. BMW's alternator on demand system has a large range of variables as to how much voltage it puts out, and at what rate, and when. Have you heard of the issues with older style batteries being replaced and the system not being coded that there is a new battery, and the new battery being ruined because it was overcharged ? The alternator and charging system takes into account the overall "health" of the battery and adjusts the amount and rate of charge. If it doesn't know the battery has been replaced, it doesn't adjust this charging rate and kills the battery, as new batteries and used accept current differently.

Now imagine the system thinks there is a different type of battery, with a different overall voltage and a physical difference as to the rate it can accept charge, etc. Do you think that it will end well? I don't. Suggest you read up more on the BMW charging system, and battery technology in general.

Tell you what, go buy a battery out of an F30 and throw it in and see what happens.

[JoeFromPA]

Originally Posted by Needsdecaf

Yeah, I read that. I'd love for you to explain how it states your case? The nominal voltage is not even the same.....??

As far as the "assessment that the battery is safe to use", it's a little more complicated than that. BMW's alternator on demand system has a large range of variables as to how much voltage it puts out, and at what rate, and when. Have you heard of the issues with older style batteries being replaced and the system not being coded that there is a new battery, and the new battery being ruined because it was overcharged ? The alternator and charging system takes into account the overall "health" of the battery and adjusts the amount and rate of charge. If it doesn't know the battery has been replaced, it doesn't adjust this charging rate and kills the battery, as new batteries and used accept current differently.

Now imagine the system thinks there is a different type of battery, with a different overall voltage and a physical difference as to the rate it can accept charge, etc. Do you think that it will end well? I don't. Suggest you read up more on the BMW charging system, and battery technology in general.

Tell you what, go buy a battery out of an F30 and throw it in and see what happens.

How does it support my case? You mean the part where BMW has a table that puts LI-Ion and Lead-Acid/AGM right next to each other and says Lead-Acid/AGM "application range = every vehicle"?

I mean, I guess that could be ambiguous to some and you need me to further justify "my case" as I'm personally taking you to court of this matter

...

All sarcasm aside, I'm trying to establish clear guidance for various owners who might have a stranding/drained battery situation. I'm not representing myself as an expert and you yourself re-shared the document i'm now relying upon where, though the specifications are quite different, BMW is saying that the Lead-Acid/AGM type 12-volt battery has a application range of every vehicle.

I have no bone in this debate one way or another. If someone proves the opposite, I'm all ears. The reason you posted that document was because I made a comment about if "BMW says something else, I'll gladly stick with LI-Ion only".

But the document indicates Lead-Acid/AGM would function fine (albeit without battery sensing electronics). So either:

1. Lead-acid/AGM is fine
or
2. BMW has grossly mis-stated the reality and neither their owners manual nor technical documents make any sort of either direct or easily understood statement that AGM/Lead-Acid batteries SHOULD NOT be hooked up to an F80.

Joe

P.s. It's page 87 of the document. bottom of the table.

[JoeFromPA]

Originally Posted by Needsdecaf

The nominal voltage is not even the same.....??

P.s. Why would nominal voltage be a determiner? Batteries crank out varying voltages for vehicle starting everyday due to temp and charging status. AFAIK it's fairly normal for a vehicle to start off of 10-13 volt discharge and BMW itself says the LI-Ion battery will start the vehicle just fine as long as it's sensing at least 10 volts.

Genuine question as to my automotive knowledge, when it comes to batteries, it will be rated at one voltage but will discharge usually lower in various real world situations.

[Arcoril]

Originally Posted by JoeFromPA

All sarcasm aside, I'm trying to establish clear guidance for various owners who might have a stranding/drained battery situation.

I'm in the same boat. I feel a little better knowing that if I'm far from a BMW dealership that I'd be able to walk into a Wal Mart, auto parts store, or call AAA to swap a battery if I'm stranded.

[huatian]

batteries in of themselves are not intelligent devices - that's pretty obvious. The most important thing is the charge rate as to charge it correctly. BMW can be doing this in a couple of different ways. First a micro controller - [mc] is used which has a parameter for battery type. Measurements are taken from the battery a battery sensor that is inline and fed into the mC. The mc will adjust the output voltage to meet the battery type. The sensor if it's in line or in the battery would be talking back to the mc most likely via CAN bus and provide it with various parameters - V, I, Temp and Time. You can't get anything more from a battery. The mc then can relay this info to other mc and make conditional decisions i.e. if V <= 11.2 don't start the engine etc or if batt_type = Li-Po time <= 120Min at 14v, 5A etc.

My intuition tells me, they use a constant charge rate for all cars less i series. An mc dedicated to measuring specific parameters on batteries (V, I, Temp, time). For all Li-ION, the charger is in the battery, but nothing else. This in turn makes for a easier system build as most of the BMW will use an AGM battery. Bat state will come from the specific battery sensor. When you think of it, for batteries regardless of type, you need to same info V, I, Temp and time (time as is in how long your charging).

When my car shows up, I will check the battery, if i see a connection to other then Neg / Pos, I will tap a logic analyzer on it and see what data is going back and forth for those really interested. If state info is going back and forth then dropping in any battery probably isn't going to work as you'll need a sensor sending back that state info. If that state info not coming from the battery but further uplink as i described before, then dropping in an AGM battery will be fine.

[vonmayr]

Battery and charging system functionality is described in the complete vehicle information PDF. The advanced battery monitoring circuitry present in the M3 has the following functionality:

The integrated electronics, the so-called battery supervision circuits (BUE), are responsible for the:

• Communication via LIN data bus with FEM/DME
• Diagnostics
• Wake-up function via FEM via LIN data bus
• Current monitoring of the individual cells and battery
• Closed-circuit current monitoring
• Voltage monitoring of the individual cells and battery
• Cell voltage adaptation with counter function via passive system (resistance)
• Startability monitoring
• Temperature monitoring with resulting temperature model
• Internal resistance monitoring
• State of charge monitoring
• Battery condition monitoring
• Battery capacity monitoring
• Data memory for battery information
• Activation of the battery isolating switch in the event of a fault.


The battery circuitry wants the battery to be operating between 10 and 14.5 volts, and most of the functionality revolves around isolating the battery (a switch opens) if the battery is operated outside that voltage range (not a concern for a Pb Acid battery), protecting the battery against to much charging current or too much current draw, and preventing the battery from getting above 80 degrees C (battery fires start at much higher temperatures).

Since a Pb battery won't have this circuitry in it (inside the battery only) Informed guess says the car would not start with a Pb battery because it is not connected to the bus with the circuitry.

[Dackelone]

Some new info...


vonmayr
JoeFromPA
huatian
Arcoril
Needsdecaf
huatian

For all your techie types... I asked my buddy at BMW AG some more questions on the F8x charging system. Here is what he had to say. He also gave me a great pdf on the Intelligent Alternator Control (IGR in German!) used on all BMW's since 2007. What's most interesting is his last paragraph...

Dackel



Li-ion battery in F8x ///M’s...

every BMW comes with this function(IGR) since 2007 build date.

- When you brake your car increases the voltage of the generator, so it produces more energy. This higher energy output causes a counter force on the (FEAN) belt which result in slowing down the engine/car. It's like turning on a bicycle dynamo...

- For this function you need an AGM battery (or Li-Ion), an IBS (Intelligent Battery Sensor) and an IGR (Intelligent Generator Regulating -> a Generator with a bus system)

--> As a result your car produces electric energy and not only frictional heat


Official BMW explanation:

Fuel consumption is reduced by way of energy recuperation in favorable vehicle operating modes (overrun phases) based on a request to increase the alternator voltage (target value). This energy recovered without the use of fuel is stored in a "receptive battery". The charge status of the battery must be within certain levels that permit charging. A fully charged battery (100 % charged) cannot accept energy and is therefore avoided as part of the intelligent alternator control strategy.

2) I bumped into the responsible person for the 12V-battery and asked him, if you can retrofit an AGM-battery. As I guessed: yes, you can but recuperation won't work properly.
BTW: you cannot retrofit a Li-Ion battery because of the maximum charging level (AGM= 14,8V, Li-Ion=14,4V)


Also... here is what some Li-ion race batteries are selling for in Germany. Makes BMW's prices seem cheap!
http://www.isa-racing.com/index.php/...Batterien.html

.

[Needsdecaf]

There you go! Thanks Dack. Joe, I guess you are right.

So if recuperation won't work properly, what is the end result? Uncharged battery? Overcharged battery?

And to swap in an AGM, I guess you'd have to add the IBS?

[ForTehNguyen]

im guessing it recharges the battery so you can utilize auto start stop more

[vonmayr]

Originally Posted by ForTehNguyen

im guessing it recharges the battery so you can utilize auto start stop more

Right. And with the old AGM batteries, the battery monitoring circuit was in the battery leads and external to the battery. With the Li Ion batteries, it is internal to the battery and hence will cause more issues because the car is expecting to be able to "talk" to that monitoring circuitry at start up.

[vonmayr]

Originally Posted by Dackelone

Some new info...


For all your techie types... I asked my buddy at BMW AG some more questions on the F8x charging system. Here is what he had to say. He also gave me a great pdf on the Intelligent Alternator Control (IGR in German!) used on all BMW's since 2007. What's most interesting is his last paragraph...

Thanks Dak, that was an interesting read. It confirmed what I thought was happening vis a vis reducing the engine load of the alternator. This results in fuel savings because the alternator is not trying to keep the battery topped off all the time. There are set min and max charge states, and the alternator only charges (thus drawing more power from the engine) to keep the battery in between these levels. When the battery is at a certain acceptable charge level (less than full), the alternator stops charging the battery. In this way it reduces the load on the engine and increases efficiency. The battery can thus accept energy that can be generated for "free" when you are decelerating - using the existing engine kinetic energy to put full load on the alternator and more fully charge the battery.

[E90Fleet]

Originally Posted by Dackelone

BTW: you cannot retrofit a Li-Ion battery because of the maximum charging level (AGM= 14,8V, Li-Ion=14,4V)


.

Yes, this is the reason you cannot use a normal battery charger on the Li-Ion batteries, it will kill them.
The Li-Ion chargers keep their maximum voltage below 14.4V.

So fitting a Li-Ion to a "normal" car will result in its charger killing the battery.
Fitting a Lead Acid battery in a F8X will result in a not fully charged battery.

What Im not sure of is if the F8x has a coding option to allow Lead Acid batteries or not. Someone with a F8x on ISTA needs to check for us if that option appears under the battery section.

[Dackelone]

Originally Posted by E90Fleet

What Im not sure of is if the F8x has a coding option to allow Lead Acid batteries or not. Someone with a F8x on ISTA needs to check for us if that option appears under the battery section.

My friend said you can use an AGM battery(and code it) but its not going to work properly - which I took it to mean, it will not last long as it should.

[pruettfan]

Maybe I have drank the Kool Aid and didn't know it but I actually think this is not a terrible battery for this car. Li-ion batteries are superior than lead acid or AGM batteries and should yes should last for 8-10 years assuming BMW got the charging system right. Here in AZ I go through lead acid batteries every 2-3 years, BMW charges about $400 here to change out the battery and do the programing. On my 06 330i I got so irritated last time that I bought an AGM battery put it in and skipped the programing. That was 2 years ago and it has been fine so I am thinking some of that programing stuff is BS. Point is over a 10 year period I would spend $1200 on batteries for a regular 3 series so perhaps combined with 30 lbs of weight savings this is not so bad.