Hello! As we are aware, to jump start the Octavia III (with stop-start) you cannot just connect   [donor -]   to  [dead -]  & [donor +] to [dead + ] as you can on older cars; you have to connect the donor negati ve to the dead octy's earthing point so as not to screw things up.

 

However...how would you go about jump starting someone elses car? Would the same configuration work (  [Octy +]   to  [dead +]  /  [Octy  earth]  to [dead -])?

 

Or are you able to connect to both positive and negative of the octys battery in this instance, providing you connect to the dead cars earth, not negative..?

I wouldn't even care to try it nowadays tbh for the reasons you mention....

if someone rocking a car nowadays without any kind of breakdown cover, thats their own ( silly) choice and you pays your money, takes your choice,

 

Some hotty broken down you were trying to impress huh ?

All modern vehicle's manufactures recommend that negative must always be connected to some earth point and never to negative on the battery (dead car). 

The last time I called out the RAC when my battery went flat, the RAC patrolman connected the positive terminals of both batteries first and the negative terminal of my (flat) battery to an earthing point on his van's front bumper.  Electrically that is the same as using your earthing point to connect to the negative terminal of the car you are trying to jump start.

 

The main reason for using a remote earthing point is to keep any sparks away from the battery, which can give off hydrogen when it is charging.

 

Provided you don't get the polarities mixed up you should be fine.

All modern vehicle's manufactures recommend that negative must always be connected to some earth point and never to negative on the battery (dead car).

That's easy if you carry a ground spike and a hammer with you

I have jumped another diesel from my octavia.

Red + to red +

Flat battery black - to octavia chassis -

Job done. No drama no dilemma.

That's easy if you carry a ground spike and a hammer with you

Sorry?What will all those staff will be needed for? You have to drill ground points to your car? If yes you don't have! Your car has already from the factory lot's of ground points. I would be happy to tell you some points if you don't know where they are.

Yes agreed the whole chassis should be bonded to allow the working current to flow back to the - pole on the battery.

Ground typically allows working current to flow back to the - pole.

Earth is a means to provide protection If undesirable voltages appear on something.

The jollygardener was correct that the point used on the rac van bumper was at the same potential as the - pole on the battery.

It's not complicated. But for example when measuring a car battery voltage would you not reference your measurements to the battery - pole and not to an ambiguous earth point or indeed reference to the car tyre which do conduct somewhat but there may lie a potential difference between the two.

Anyway. As said I have jumped a diesel car on a few occasions now with no drama. Are cars really so 'fragile'. Two batteries connected together In parallel is not a worry. Just means twice the available current is available.

The last time I called out the RAC when my battery went flat, the RAC patrolman connected the positive terminals of both batteries first and the negative terminal of my (flat) battery to an earthing point on his van's front bumper.  Electrically that is the same as using your earthing point to connect to the negative terminal of the car you are trying to jump start.

 

The main reason for using a remote earthing point is to keep any sparks away from the battery, which can give off hydrogen when it is charging.

 

Provided you don't get the polarities mixed up you should be fine.

Sounds strange, most breakdown vehicles have a lorry plug they put the jump leads in, my old Ex-rac van did.

Personally, in these days of batteries covered in junction boxes and maxi fuses, I use a booster pack. No point creating a problem on one car just to get another going.

The last time I called out the RAC when my battery went flat, the RAC patrolman connected the positive terminals of both batteries first and the negative terminal of my (flat) battery to an earthing point on his van's front bumper.  Electrically that is the same as using your earthing point to connect to the negative terminal of the car you are trying to jump start.

 

The main reason for using a remote earthing point is to keep any sparks away from the battery, which can give off hydrogen when it is charging.

 

Provided you don't get the polarities mixed up you should be fine.

tosh

I wouldn't even care to try it nowadays tbh for the reasons you mention....

if someone rocking a car nowadays without any kind of breakdown cover, thats their own ( silly) choice and you pays your money, takes your choice,

 

Some hotty broken down you were trying to impress huh ?

:D  I wish! Chance would be a fine thing!

 

The last time I called out the RAC when my battery went flat, the RAC patrolman connected the positive terminals of both batteries first and the negative terminal of my (flat) battery to an earthing point on his van's front bumper.  Electrically that is the same as using your earthing point to connect to the negative terminal of the car you are trying to jump start.

 

The main reason for using a remote earthing point is to keep any sparks away from the battery, which can give off hydrogen when it is charging.

 

Provided you don't get the polarities mixed up you should be fine.

 

 

Yes agreed the whole chassis should be bonded to allow the working current to flow back to the - pole on the battery.

Ground typically allows working current to flow back to the - pole.

Earth is a means to provide protection If undesirable voltages appear on something.

The jollygardener was correct that the point used on the rac van bumper was at the same potential as the - pole on the battery.

It's not complicated. But for example when measuring a car battery voltage would you not reference your measurements to the battery - pole and not to an ambiguous earth point or indeed reference to the car tyre which do conduct somewhat but there may lie a potential difference between the two.

Anyway. As said I have jumped a diesel car on a few occasions now with no drama. Are cars really so 'fragile'. Two batteries connected together In parallel is not a worry. Just means twice the available current is available.

 

I'm not really too fussed about damaging the battery itself, or causing sparks which may ignite any gas that's escaped; that's the same for any vehicle new or old. I'm more concerned as i've heard that you can end up frying the ECU, other components/systems and something to do with the stop-start if you're not careful on newer cars with more sofisticated systems.

 

So it doesn't matter on which vehicle you clip the negative cable to the earthing point, whether it's the dead car or the donor, so long as one of them is?

Who has fried to some degree their electronic system during a battery boost?

Cant remember now, might have even been someone on here..

Also the manual says you mustn't ever connect to the battery's negative, but that only details jump starting the octavia, not others. I'm no good with electrical stuff, don't really understand it.

I jump started a neighbour's diesel van a few months ago. Just did + to + then - to ground to ground and left my car running for 5 mins before starting the van. Didn't occur to me that there was any reason I shouldn't do this.

Pro vehicle recovery firms use a separate booster box that they connect direct to your battery, they don't use their own.

 

 

tosh

 

Yeah you can always trust the RAC with your battery.

Has anyone damaged their car doing a boost?

To be safe I would connect the earthing point to earthing point rather than minus on the battery.

However, I think the risk of damaging something going minus to minus is small.

 

I've never heard of someone frying an ECU charging this way, but then again modern batteries & battery management is much more reliable these days so its not often you need a jump start even if you leave your lights on.

 

On many cars the packaging of the battery prevents simple access to one of the terminals but I guess the main reason for this is its no longer needed due to "chassis grounding point" rather than because its dangerous to connect directly to it.

This 'damaging components etc' is old (Skoda) wives tales.

You hit the nail on the head that battery terminals can be awkward to access so why bother removing all manner of plastic to access the - terminal when the chassis is connected to it.

This 'damaging components etc' is old (Skoda) wives tales.

Isn't it supposed to be that you might confuse the battery monitoring software if you take current out of the battery that it can't see, rather than because there's a risk of damage?

I wouldnt say its an old wives tale, its written in the manual of pretty much every modern car these days.

 

A well designed electrical module should be protected against electric problems (like connecting the battery the wrong way round) but with modern electronics its easy to imagine that they are quite sensitive & perhaps theres a possibility that with the load from 2 alternators theres an increase chance of damaging something...

Has anyone damaged their car doing a boost?

 

Minor fireworks only when the owner of the other car got red and black the wrong way round.

 

I haven't used another vehicle to do a jump start in years, I find most of the problem is getting access to the battery and the other half of the problem is getting a decent connection with the leads. Using the little booster pack saves half of this bother straight away.

Biggest problem jumping a RHD Skoda with a flat can be getting the bonnet open in the first place! but I won't resurrect that one 

 

Not had it with a Skoda but jumping one of our others normally resulted in warning lights on and gauges all over the place. Cured by pulling a few fuses but still a pain.

 

A lot of problems are caused by the spark that can jump just as you are connecting the wires especially if the battery is very flat. it is a good idea to be 'positive' when doing clamping the leads on. It can spike the system especially if the 'donor' car is running and being revved. 

I wouldnt say its an old wives tale, its written in the manual of pretty much every modern car these days.

A well designed electrical module should be protected against electric problems (like connecting the battery the wrong way round) but with modern electronics its easy to imagine that they are quite sensitive & perhaps theres a possibility that with the load from 2 alternators theres an increase chance of damaging something...

But a circuit will only 'draw' the current it needs unless there is and earth fault etc. Two batteries in parallel (I.e. When jump leads attached) only increases available current and not voltage. Agreed that an overvoltage to a circuit can be dangerous (if not suitably protected or regulated) but the voltage remains ballpark 12Vdc not accounting for any alternator output.

One thing strikes me is that not many owners have much faith in skoda engineering.

if you have a start/stop version and you are providing power for someone else, you must not connect the neg lead to the chasis as this will mess up the start/stop monitor components as the vehicle with the good battery you should have the leads direct on your battery. But is you are the one needing the power then the neg must be connected to the chasis.

 

John

if you have a start/stop version and you are providing power for someone else, you must not connect the neg lead to the chasis as this will mess up the start/stop monitor components as the vehicle with the good battery you should have the leads direct on your battery. But is you are the one needing the power then the neg must be connected to the chasis.

John[/quote

I would suggest that the monitoring system and other monitoring systems are isolated from the actual source/load by some optical coupler. This is a usual means to provide component safety from 'higher' powered devices/components.

Maybe skoda don't engineer these safety devices into their electronic systems?

Electronic lesson over.