It's my turn... Battery System Failure
04-02-2017, 10:22 PM
#21
AudiWorld Wiseguy
Nothing will actually burn up per that anecdotal BMW 7er story (horribly fragile things by all accounts). But there is no doubting that the BMS has direct control of the alternator current, so by association also the charging current based on what it has assumed the battery health to be.
And that's the thing, it's a system that makes assumptions on battery health based on historic readings. It's not a system that checks battery health in real time. It's not that clever, but then it doesn't need to be. For this purpose, 99.99% of the time an assumptive system is perfectly adequate as the assumption is that when a core part of the system (the battery) is changed, you tell it, so it can adjust to suit. Not telling it is obviously going to throw it off for a while, along with the shut down stages and charging current profiles until it figures out that the battery is now back to performing normally,
If you have the tool to do the job properly, then do it properly. The only person who's time and money that could in the future go to waste as a result of choosing to not do it properly is your own.
And that's the thing, it's a system that makes assumptions on battery health based on historic readings. It's not a system that checks battery health in real time. It's not that clever, but then it doesn't need to be. For this purpose, 99.99% of the time an assumptive system is perfectly adequate as the assumption is that when a core part of the system (the battery) is changed, you tell it, so it can adjust to suit. Not telling it is obviously going to throw it off for a while, along with the shut down stages and charging current profiles until it figures out that the battery is now back to performing normally,
If you have the tool to do the job properly, then do it properly. The only person who's time and money that could in the future go to waste as a result of choosing to not do it properly is your own.
04-03-2017, 09:21 AM
#22
AudiWorld Super User
Thread Starter
I'll re-code, just want to see how long it will take to have
100% charge indicator from 0% bad batttery - 10% with new battery - After driving about 20 miles - 1/2 hour - the charging indicator came up to 70%. So the PEM does work regardless.
Cheers,
Louis
Cheers,
Louis
04-08-2017, 09:39 AM
#25
AudiWorld Super User
04-08-2017, 04:00 PM
#26
After reading about all views of different makes of Battery and I decided Walmart EverStart Maxx H8 was the best choice for my car at this moment. I haven't done the VCDS. Everything seems to work fine.
I do know something about charging system since I'm in the field. I don't believe all the assumptions about the charging system can reduce the charging current (capacity) to adapt to current battery condition because they can't check dynamically.
https://www.youtube.com/watch?v=abO6tF4OskE
How to test a battery to see if it's good? - put a load and see the battery drops in voltage and how long does it hold the voltage.
The charging system can only sense the voltage drops with a fixed load and charge it accordingly.
All charging systems will turn off when the battery is full providing second source is running like your electrical devices: smart phones.
In order to limit the charging current, there must be dynamic resistance in series which can be in the form of Potentiometers. Digital potentiometers only for microcontrollers and not really for high current and voltages. I don't see this is viable for any car application especially in 2006. So if BMW or Audi said that you can burn up your alternator or new battery if you don't tell the system that the new battery is installed is BS (NOT bachelor of science). Unless they have a "secret ingredient".
Alternator is running and producing the same current and voltage by regulator all the time - when the battery is full or dead, you're running on alternator regulator and current if your alternator is good.
If there is a dynamic analog potentiometer which I don't know about, it wouldn't last with all these exercises with changing current all the time and whoever design this system is NOT economically sound for any reason.
Remember ohms law V(voltage)=I(current)xR(resistance). Voltage is the same, then to change current, resistance must change accordingly.
Cheers,
Louis
I do know something about charging system since I'm in the field. I don't believe all the assumptions about the charging system can reduce the charging current (capacity) to adapt to current battery condition because they can't check dynamically.
https://www.youtube.com/watch?v=abO6tF4OskE
How to test a battery to see if it's good? - put a load and see the battery drops in voltage and how long does it hold the voltage.
The charging system can only sense the voltage drops with a fixed load and charge it accordingly.
All charging systems will turn off when the battery is full providing second source is running like your electrical devices: smart phones.
In order to limit the charging current, there must be dynamic resistance in series which can be in the form of Potentiometers. Digital potentiometers only for microcontrollers and not really for high current and voltages. I don't see this is viable for any car application especially in 2006. So if BMW or Audi said that you can burn up your alternator or new battery if you don't tell the system that the new battery is installed is BS (NOT bachelor of science). Unless they have a "secret ingredient".
Alternator is running and producing the same current and voltage by regulator all the time - when the battery is full or dead, you're running on alternator regulator and current if your alternator is good.
If there is a dynamic analog potentiometer which I don't know about, it wouldn't last with all these exercises with changing current all the time and whoever design this system is NOT economically sound for any reason.
Remember ohms law V(voltage)=I(current)xR(resistance). Voltage is the same, then to change current, resistance must change accordingly.
Cheers,
Louis
A smart battery charger will sense battery condition and run algos to prevent battery damage. Read up on it. I think they don't want gassing off, and elevated plate temps.
Field current to the alternator controls its output voltage, and torque that is applied to the engine. Which is why a properly charged and functioning battery = greater fuel efficiency. By my estimation a new battery should be able to tolerate higher re-charge currents (therefore voltage). The battery from the Audi dealer was very reasonable. I paid just $50 more than a battery for my son's TT at Can tire.
04-09-2017, 08:49 AM
#27
AudiWorld Super User
Lootz, you should look into teaching Electrical Engineering at the university level with those new theories and terms you've come up with.
Well, maybe at a "nine month wonder" technical institute.
Well, maybe at a "nine month wonder" technical institute.
04-09-2017, 11:25 AM
#28
AudiWorld Super User
Thread Starter
I'm so sorry for being a blabbermouth...
Audi is considered an upper middle class car company - targeting clienteles with average income of $125k a year for individual ($250k/family) - which means average intelligent people. Audi doesn't expect its clienteles to do their own work because they're should be busy making more money to buy the next new Audi. So, why this forum?
One thing I found that's not logical in this forum is that if you want to be a true Audi owner, you shouldn't be here, just take the car to the dealers or shops, then again I'm blabbing.
I do get paid well to question illogical designs and that's my specialty.
Yes it's true, to test battery we need load... the question is what kind of load and what confirms a bad battery.
I read enough up here to say that not many people should be owning an A8 due to "requirements".
I'm not here to debate about how much I know about Audi, but to share what I've done to help people to save money in a non biased way... I'm not a hypocrite.
- You don't have to buy original discs to update firmware on MMI - I did it with burned cd - You bricked your MMI head unit is because you're not following a correct procedure and not smart enough to watch a real video process from beginning to end.
- You don't have to buy a real VCDS if you can find a clone and use it as instructed and you won't break your car, unless you do something that you shouldn't do. This one to me is just Good/Bad integrity (karma).
- The original Timing Belt can last up to 119k miles like my car. Again, I'm pushing it.
BTW - the BAD battery indicator didn't even come on when my battery died over night. What does it say about the sophisticated PEM system?
Back to the battery -
- If the system is so smart to tell if the battery is healthy or weak and adjust the charge accordingly, why does it need to be told that a new and healthy battery was just installed? Why am I keep dwelling on this and not just re-code the darn battery since I have a real $349 VCDS? It's only to prove something so that later, someone who doesn't have the VCDS can be safely replace a cheap battery and drive the car without worrying about it if they read this post. Yes, I can afford to kill a new battery to prove something that's not logical.
Cheers,
Louis
One thing I found that's not logical in this forum is that if you want to be a true Audi owner, you shouldn't be here, just take the car to the dealers or shops, then again I'm blabbing.
I do get paid well to question illogical designs and that's my specialty.
Yes it's true, to test battery we need load... the question is what kind of load and what confirms a bad battery.
I read enough up here to say that not many people should be owning an A8 due to "requirements".
I'm not here to debate about how much I know about Audi, but to share what I've done to help people to save money in a non biased way... I'm not a hypocrite.
- You don't have to buy original discs to update firmware on MMI - I did it with burned cd - You bricked your MMI head unit is because you're not following a correct procedure and not smart enough to watch a real video process from beginning to end.
- You don't have to buy a real VCDS if you can find a clone and use it as instructed and you won't break your car, unless you do something that you shouldn't do. This one to me is just Good/Bad integrity (karma).
- The original Timing Belt can last up to 119k miles like my car. Again, I'm pushing it.
BTW - the BAD battery indicator didn't even come on when my battery died over night. What does it say about the sophisticated PEM system?
Back to the battery -
- If the system is so smart to tell if the battery is healthy or weak and adjust the charge accordingly, why does it need to be told that a new and healthy battery was just installed? Why am I keep dwelling on this and not just re-code the darn battery since I have a real $349 VCDS? It's only to prove something so that later, someone who doesn't have the VCDS can be safely replace a cheap battery and drive the car without worrying about it if they read this post. Yes, I can afford to kill a new battery to prove something that's not logical.
Cheers,
Louis
Last edited by ltooz_a6_a8_q7; 04-09-2017 at 11:36 AM.
04-09-2017, 01:57 PM
#29
AudiWorld Wiseguy
https://en.m.wikipedia.org/wiki/Upper_middle_class
04-09-2017, 02:06 PM
#30
AudiWorld Member
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Seems like these things hit you right before they hit me - first the suspension, now I'm having battery issues as well. Thanks for the hard work!
And I agree with the upper-middle definition, in my area making that much will hardly leave enough money for a base A4, let alone a W12.
And I agree with the upper-middle definition, in my area making that much will hardly leave enough money for a base A4, let alone a W12.