Car battery is not charging

[Martbar]

Obviously the Owners Handbook should be your first point of reference.
As previously mentioned the sealed for life auto's and the low cca of the manufacturers specified battery's would seem to be two glaring inconsistencies.
With ideal driving situations eg
regular use and longer trips the manufacturers specified battery would probably be okay.
But in the real world the consensus of option seems to be that they need a bigger battery.
Stooge and chrisp are two members whose opinions l respect and value.
Its been about 20 years since I've had to jump start a car, and although it might be a million to one shot,(the potential spiking causing damage to electrical components) if l remember Haha.
I'm going to turn the ignition off before disconnecting the cables.
Before starting the car,l turn the key to reds and then wait until the safety check has been completed.
They certainly don't do this at the dealership and they would probably tell you that its a waste of time. I read a post on the j.c. forum where a member said that they believed waiting for the vehicle to complete the safety check could be beneficial.
I couldn't find any reference for this one way or the other in the Handbook.
Cheers.

 

[chrisp]

*citation needed

will happily wait for you to produce the documentation stating that gm has designed the ve/vf to run without a battery.

I didn’t say such thing. I said that it’s a foreseeable fault condition. ‘Tolerate’ doesn’t necessarily mean run or function normally. It could simply mean shutdown without causing a permanent fault.

My use of ‘tolerate’ was in the context of the individual modules being designed to cope with voltage spikes and other abnormal conditions (e.g. reverse polarity comes to mind). Personally, I’d certainly attempt to design in fault tolerance for those scenarios, but cars are pretty complicated and many of the modules are designed by third parties. It’s very easy to overlook something along the way in either the specification, design, construction or testing processes.

The point I’m trying to make is that starting the car and then disconnecting the battery is the same scenario as jump starting a car that has an open circuit battery (if the jump leads are removed while it is running).

We are dealing with remote odds here. How often do we actually need to do a jump start? How likely is it that we have an open-circuit battery? And then, how often could a spike occur that exceeds the tolerance of one of the modules in the car?

I certainly wouldn’t lose sleep over it. I’m certainly not stressing over how someone else decides to jump start their car.

Just as an aside, I had a colleague who went on the work at a well known electronics company who manufactured many of the modules used in the local cars. He worked on making the test beds used to check the completed modules. He made an interesting comment. He said that only one manufacturer (headquartered in Japan) insisted on full functional testing of all their modules. He said that in the future that he would only buy their cars. His view was that the testing done for the other brands was pretty basic.

Another example I can recall (albeit secondhand, but from a reliable source) was that there was a strange occurrence of (some particular model) trucks breaking down along some highways. There was a lot of head scratching going on trying to find out why as the fault would mysteriously disappear and couldn’t be replicated in the workshop. It took the manufacturer a while to work out the issue. The particular trucks were somehow susceptible to the electric fields under the high voltage power lines.

 

[lmoengnr]

Obviously the Owners Handbook should be your first point of reference.
As previously mentioned the sealed for life auto's and the low cca of the manufacturers specified battery's would seem to be two glaring inconsistencies.

The service handbook specifies 150k for a 6L80e trans service.

 

[losh1971]

The service handbook specifies 150k for a 6L80e trans service.

Well that doesn't sound like a good idea. The trans places I've dealt with suggest 60k-65k intervals.

 

[stooge]

The point I’m trying to make is that starting the car and then disconnecting the battery is the same scenario as jump starting a car that has an open circuit battery (if the jump leads are removed while it is running).

no its not and once you learn how a battery works you will understand why its not the same as pulling the battery lead.

How likely is it that we have an open-circuit battery? And then, how often could a spike occur that exceeds the tolerance of one of the modules in the car?

the thing here is the modern modules are designed to handle voltage spikes because they contain a regulator circuit and many of the modules have 5 volt logic so any voltage in is reduced to 5 volts, in many cases a module will be able to take 24volts in and still step it down correctly.

what a voltage regulator does not do is step the voltage up so a low voltage condition is actually a problem, the use of capacitors can help in the low voltage scenario but not for long, a couple of seconds at best.

by disconnecting the vehicles while running the "jumped" vehicles alternator is powering the system sufficiently so there is no issue with disconnecting it as per the specified procedure.

the ve/vf has a shut down process when you turn the key off that has 3 or 4 stages over about 60 seconds.

now i would speculate that the reason the manufacturer says to disconnect while running is so the system can correctly measure the battery condition and preform the shutdown based on that measured condition.

if you have another vehicle connected while you shut down the vehicle the system cannot correctly measure the battery condition and may very well think everything is fine and start saving data to modules right when you are disconnecting the other vehicle which causes an unexpected low voltage state causing corruption in modules aka bricking them.

if you disconnect the other vehicle while both are running as per manufacturers procedure then the system can measure the battery condition and it can detect there is an issue and go into a safe shutdown mode without bricking things.

this is just a speculation on how the system works because i am not a gm engineer but i have seen this type of system in many other large industrial machines that have computer systems so i would suspect that gm must have a system to protect non volatile memory within the modules or we would be witnessing much more module failures than we do.

at the end of the day you can perform the procedure how you like but taking information from other systems and broadly applying it to everything similar is only asking for trouble because while they might be similar they are actually different and this is why with technical machinery it always pays to reference the manufacturers procedure for a given task instead of coming up with your own theory on how to do it.

EDIT: i should add i am not saying that your method is totally wrong for everything i am just saying to follow what the manufacturer specifies because there is a reason they specify it and we dont know what that is

 

[lmoengnr]

Well that doesn't sound like a good idea. The trans places I've dealt with suggest 60k-65k intervals.

Yeah, but it doesn't state 'sealed for life'.

 

[losh1971]

Yeah, but it doesn't state 'sealed for life'.

Yes and no. I'd go as far as to say that if you went 150k with no oil change the trans would be close to its end of life.....

 

[lmoengnr]

Yes and no. I'd go as far as to say that if you went 150k with no oil change the trans would be close to its end of life.....

Don't flog it and have a decent trans cooler and it'll probably be fine.

 

[chrisp]

no its not and once you learn how a battery works you will understand why its not the same as pulling the battery lead.




the thing here is the modern modules are designed to handle voltage spikes because they contain a regulator circuit and many of the modules have 5 volt logic so any voltage in is reduced to 5 volts, in many cases a module will be able to take 24volts in and still step it down correctly.

what a voltage regulator does not do is step the voltage up so a low voltage condition is actually a problem, the use of capacitors can help in the low voltage scenario but not for long, a couple of seconds at best.

by disconnecting the vehicles while running the "jumped" vehicles alternator is powering the system sufficiently so there is no issue with disconnecting it as per the specified procedure.

the ve/vf has a shut down process when you turn the key off that has 3 or 4 stages over about 60 seconds.

now i would speculate that the reason the manufacturer says to disconnect while running is so the system can correctly measure the battery condition and preform the shutdown based on that measured condition.

if you have another vehicle connected while you shut down the vehicle the system cannot correctly measure the battery condition and may very well think everything is fine and start saving data to modules right when you are disconnecting the other vehicle which causes an unexpected low voltage state causing corruption in modules aka bricking them.

if you disconnect the other vehicle while both are running as per manufacturers procedure then the system can measure the battery condition and it can detect there is an issue and go into a safe shutdown mode without bricking things.

this is just a speculation on how the system works because i am not a gm engineer but i have seen this type of system in many other large industrial machines that have computer systems so i would suspect that gm must have a system to protect non volatile memory within the modules or we would be witnessing much more module failures than we do.

at the end of the day you can perform the procedure how you like but taking information from other systems and broadly applying it to everything similar is only asking for trouble because while they might be similar they are actually different and this is why with technical machinery it always pays to reference the manufacturers procedure for a given task instead of coming up with your own theory on how to do it.

EDIT: i should add i am not saying that your method is totally wrong for everything i am just saying to follow what the manufacturer specifies because there is a reason they specify it and we dont know what that is

I’ve tried hard to make my my reasoning clear and I’ve even provided some examples of where manufacturers have actually gotten the spike and emf tolerance wrong.

I humbly suggest you be a little mindful that you actually have absolutely no idea of my background, so please don’t assume or guess that I don’t have any knowledge or experience in the field.

I‘m not here to get in to arguments, but rather to share a little bit of knowledge here and there. I do try to put my reasonings up and allow the reader to decide whether there is a basis for my views or not.

BTW I do value and appreciate the many contributions you have, and do, make to this forum. So, no hard feelings from my part. I just don’t want to continue a discuss/thread that seems to be going south. Perhaps we can just agree to disagree?

I think I’m done here, so over and out!

 

[Martbar]

The service handbook specifies 150k for a 6L80e trans service.

The only reference that l could find was for 4&6 speeds.
Stop start driving, excessive idling
or low speed operation as experienced in inner city driving.
The examples were taxi's, door to door deliveries and police.
Caravan or trailer towing
Extended heavy load, high speed operation in outside temperatures
above 35°C.
In the above circumstances they recommend trans fluid and filter
change every 75,000.
The actual maintenance schedule states that trans fluid and filter changes are not required for 4&6 speeds under normal driving circumstances.
Cheers.