Is disconnecting the battery earth ... the same as removing both terminals ?

[Submariner1]

My neighbour asked me the question regarding all the ICs, transistors, capacitors and diodes etc. And the possible damage one might do to a complex modern car, if it is not.

I initially assumed it was, but then Technically I am hopeless with electrics.

But then I thought current travelled from Positive to Negative but then read somewhere that the ions flow the other way:-0
LOL

 

[AMGeed]

Surely removing the earth breaks the circuit and removing the + lead won't make any difference?

I'm also dull when it comes to car electronics.

 

[Naraic]

Remove both.

 

[joderest]

Some electronic componants have capacitors which store currant, and discharge slowly. Hence disconnecting the battery does not entirely kill all the electrics, I do not know how long it would be until all power gone from systems

 

[Botus]

the majority of capacitors will have lost it with 24hrs, many within the hour - hence most manuals say wait 30 mins to play with an airbag after disconnecting the battery

if you take off both then ensure they aren't touching anything or the risk will be higher than leaving it alone

scare stories are mainly around nasty electrics which are failing anyway and or systems when they designed in a mess up the non trained mech intentionally.... seems some modern triumph bikes can't cope if you disconnect the tank and a special sequence is required to get it up and running again

 

[Submariner1]

Surely removing the earth breaks the circuit and removing the + lead won't make any difference?

I'm also dull when it comes to car electronics.

That was my original thought.
But thought I would check as he is going to “add” a JL amplifier and Sub to his very nice Audi
... braver than me LOL

 

[Submariner1]

the majority of capacitors will have lost it with 24hrs, many within the hour - hence most manuals say wait 30 mins to play with an airbag after disconnecting the battery

if you take off both then ensure they aren't touching anything or the risk will be higher than leaving it alone

scare stories are mainly around nasty electrics which are failing anyway and or systems when they designed in a mess up the non trained mech intentionally.... seems some modern triumph bikes can't cope if you disconnect the tank and a special sequence is required to get it up and running again

Thanks good tip

 

[Naraic]

That was my original thought.
But thought I would check as he is going to “add” a JL amplifier and Sub to his very nice Audi
... braver than me LOL

When I added an amp the advice was to disconnect both and then when reconnecting not to leave the neg off for more than absolutely necessary.

 

[Paul1948]

Disconnect the positive side and mask the terminal of the battery as a minimum safety as the negative is the same as any part of the car's metalwork if the car is not a vintage car, best to actual remove the battery if you are unsure of electrics. Latest generation of cars many have 48 volts not just what has been standard 12v for many decades.
Enjoy what you are about to under take, you should enjoy the results.

 

[Submariner1]

When I added an amp the advice was to disconnect both and then when reconnecting not to leave the neg off for more than absolutely necessary.

Thanks I will let him know, out of interest did they say what the logic was about not leavi g just the positive on for a long time was?

I assume the same principle applies to a big 2016 Audi?

 

[Submariner1]

Disconnect the positive side and mask the terminal of the battery as a minimum safety as the negative is the same as any part of the car's metalwork if the car is not a vintage car, best to actual remove the battery if you are unsure of electrics. Latest generation of cars many have 48 volts not just what has been standard 12v for many decades.
Enjoy what you are about to under take, you should enjoy the results.

Thanks it is for my neighbours Audi.

48v wow that new to me!
Hmmm thats why I wouldnt mess with these OEM sound systems.

 

[Botus]

48v gets active roll bars working nicely

 

[John Laidlaw]

48v gets active roll bars working nicely

And then, therefore, your bowels!

 

[Botus]

And then, therefore, your bowels!

Uhh ?

the whole idea is to disconnect the 40mm diameter chunk of iron locking both wheels (on same axel) together so the "independent suspension" can actually operate as such when the vehicle is in a straight line, with the express function of improving ride comfort.

not sure why they haven't worked out how to make the suspension function properly instead... like these guys http://www.clearmotion.com/

 

[LostKiwi]

Uhh ?

the whole idea is to disconnect the 40mm diameter chunk of iron locking both wheels (on same axel) together so the "independent suspension" can actually operate as such when the vehicle is in a straight line, with the express function of improving ride comfort.

not sure why they haven't worked out how to make the suspension function properly instead... like these guys http://www.clearmotion.com/

Ermmm. Didnt MB do it first with Magic body control?
https://www.mercedes-benz.com/en/mercedes-benz/innovation/magic-body-control/

 

[John Laidlaw]

Uhh ?

the whole idea is to disconnect the 40mm diameter chunk of iron locking both wheels (on same axel) together so the "independent suspension" can actually operate as such when the vehicle is in a straight line, with the express function of improving ride comfort.

not sure why they haven't worked out how to make the suspension function properly instead... like these guys http://www.clearmotion.com/

Sorry, had SLs in my brain and was thinking roll bars nothing to do with suspension or anti sway ! Must pay attention

 

[Botus]

Ermmm. Didnt MB do it first with Magic body control?
https://www.mercedes-benz.com/en/mercedes-benz/innovation/magic-body-control/

sort of I guess... but its not exactly standard on all the models is it
I think the yank cheap set up coming to most cars any minute (well so they hope) works off a few sensors on the damper not some multimillion pound high def camera set up

and they quote "our technology is significantly more proactive than technology currently featured on even the markets most luxurious cars (..including the S class)"