Jump start

coco06

Hi
Any reason why it wouldn't be ok to use a chiquicento car to Jump start an A3 1.6 ?

Thanks

slimjimmc

None that I know off, so long as the battery is up to it. It's normally advised to keep the revs up on the donor car to assist its battery.

CiniO

slimjimmc wrote: »

None that I know off, so long as the battery is up to it. It's normally advised to keep the revs up on the donor car to assist its battery.

I heard that, but I can't see a reason for it really. Why is that?

Ronnie Beck

So you don't drain the battery in the donor car. Same reason all your lights go off when you crank the starer. The battery in the donor car won't be charging at idle. Probably make sense to turn lights radio etc' off too. The revs often drop in the donor car when it's idling with the increased load on the alternator. ECU would compensate on a modern car though. Did that make any sense...?

CiniO

Ronnie Beck wrote: »

So you don't drain the battery in the donor car. Same reason all your lights go off when you crank the starer. The battery in the donor car won't be charging at idle. Probably make sense to turn lights radio etc' off too. The revs often drop in the donor car when it's idling with the increased load on the alternator. ECU would compensate on a modern car though. Did that make any sense...?

I'm not sure if it makes any sense to be honest.
Bolded part is definitely not true.
If car is running at idle, alternator should charge the battery the same good as on high revs. If it works different, that means there is some problem with alternator.
I agree obviously that the more charging batter will need, the more stress on alternator and therefore it will need more momentum to do it's job and cause more stress on the engine. But any modern car (non carburator operated but electronic fuel injection) should be able to compensate for this extra power needed by increasing amount of air-fuel mixture into engine...

In my opinion and in my experience, if all electrical systems in car works right, it should make no difference if donor car is running idle or low revs.

Ronnie Beck

Pesonally in this situation I would turn off all electrics in the cinqo especially the heated seats and subwoofer and hold the engine at about 1500rpm than crank the skoda.

Del2005

Ronnie Beck wrote: »

So you don't drain the battery in the donor car. Same reason all your lights go off when you crank the starer. The battery in the donor car won't be charging at idle. Probably make sense to turn lights radio etc' off too. The revs often drop in the donor car when it's idling with the increased load on the alternator. ECU would compensate on a modern car though. Did that make any sense...?

Ronnie Beck wrote: »

Pesonally in this situation I would turn off all electrics in the cinqo especially the heated seats and subwoofer and hold the engine at about 1500rpm than crank the skoda.

I was told/read the other way around, have as much electrical equipment on in the donor car to avoid electrical surges and hold it at about 1500rpm. I used to always jump with nothing on and I've jumped a couple of times with everything on, can't say I've noticed any difference but that could just be luck.

Ronnie Beck

Del2005 wrote: »

I was told/read the other way around, have as much electrical equipment on in the donor car to avoid electrical surges and hold it at about 1500rpm. I used to always jump with nothing on and I've jumped a couple of times with everything on, can't say I've noticed any difference but that could just be luck.

I think the idea is to charge the flat battery a bit before you crank the engine. 1500 rpm for about 30 seconds should do it. Otherwise your straining the alternator on the other car as it charging a dead battery and turning a starter. It's years since I done any electronics theory so I can't explain why.

You could probably start the auidi without even running the cinqo but it can't be good for the battery especially if the audi one is completely flat or engine flooded etc. Just becaue it works deosn't make it right

dieselbug

This is my tuppence worth as regards jump starting.

Both cars stopped, keys removed, connect jump leads paying attention to correct polarity. Start donor car, run for 10 to 15 mins. Stop donor car and remove keys. Attempt start on receiving car, if it starts disconnect jump leads, if not repeat.

Running the donor car will cause a massive surge in amps on the alternator when the receiving car is trying to start. Not good.

Del2005

dieselbug wrote: »

This is my tuppence worth as regards jump starting.

Both cars stopped, keys removed, connect jump leads paying attention to correct polarity. Start donor car, run for 10 to 15 mins. Stop donor car and remove keys. Attempt start on receiving car, if it starts disconnect jump leads, if not repeat.

Running the donor car will cause a massive surge in amps on the alternator when the receiving car is trying to start. Not good.

The correct way, who has time for that?:D

Katunga

dieselbug wrote: »

This is my tuppence worth as regards jump starting.

Both cars stopped, keys removed, connect jump leads paying attention to correct polarity. Start donor car, run for 10 to 15 mins. Stop donor car and remove keys. Attempt start on receiving car, if it starts disconnect jump leads, if not repeat.

Running the donor car will cause a massive surge in amps on the alternator when the receiving car is trying to start. Not good.

That's why it better to connect the negative clamp to the frame of the car you are jumping not the battery.

dgt

There's no reason I can't think of not to use a Cinquecento to jump a 1.6 Audi. 60 amp alternator. Keep the radio, lights etc off.Don't connect the leads with the engine in the Cinq stopped. Keep the revs high (3k ish) on the Cinq when turning the key in the Audi.

Written by someone who jump started a Hino cement lorrey with a 1.2 Bravo once

piston

Anything equipped with an altenator should charge perfectly well at idle. On old engines (mid 1970s and before) you will probably find a dynamo which won't charge at idle and will require about 1200 - 1500 rpm to do anything useful.

renofan

I've used my powerful 997cc Micra to jump start a 1.6 MINI Cooper and had no problems. Also used it to jump start a 1.4 Citroen Xsara once too.