My 2nd vehicle (a Renault Trafic) as been sat idle for a few weeks and during that time I've been piddling around with it and must have had an interior light on for too long and the battery has run flat.

 

Can I jump start the van from my 64 plate 1.2 fabia or will I do some damage to the fabia's systems? (bear with me as this is the newest car I have ever had by some distance)

 

If I can jump start ok is there any procedure to follow?

 

Thanks.............It's been a long while since I've jump started anything

Ignore me. I just remembered I have one of those aldi battery chargers

It wouldn't have been a problem I think. I once jump started a Mercedes Sprinter van from a 15 year old Renault 5....

Yeah itll do it.

Connect it up, hold the revs at around 3k rpm and it should start no prob.

My HTP has done a 2.0tdi golf, R33 Skyline and a Fiesta 1.6 diesel.

No prob.

Just make sure the jump leads are up to the task... Especially if its a diesel as they need a bigger core to the leads to take the power!

Edited 9 March, 201610 yr by mrgf

I started the Octavia with my Monte 1.2 TSI a few times, connect the batteries remembering to ignore that rubbish about not putting both leads on the battery and keep it at 2k for a couple of minutes.

Edited 9 March, 201610 yr by Outofthi5world

Why oh why do people insist  on running the engine while trying to start the second vehicle, simple maths, your alternator puts out 95-100amps your starter motor uses 300-400 amps when turning engine over thus alternator trying to charge at 300amps  resulting in a damaged alternator perhaps not straight away but will eventually fail, nothing wrong in letting your car trying  to charge flat battery up that's what it's designed for  not the starter motor

Why oh why do people insist on running the engine while trying to start the second vehicle, simple maths, your alternator puts out 95-100amps your starter motor uses 300-400 amps when turning engine over thus alternator trying to charge at 300amps resulting in a damaged alternator perhaps not straight away but will eventually fail, nothing wrong in letting your car trying to charge flat battery up that's what it's designed for not the starter motor

Its already running when connecting the leads.

Not started afterwards.

I just revved it to 3k rpm for a few moments because i thought the alternatir would make more power at those rpm.

A running engine will give the power to the flat battery, quicker. You are not just starting or turning over the engine of the vehicle with the flat battery, you are trying to install a small amount of charge to energise the flat battery. Otherwise, turn off the newly jumped car and it will fail or be difficult to start again. Run the doner, give it five, all hooked up, and the flat battery will have a much better chance of charging from the alternator AFTER you start the vehicle. Never personally known a jump start to damage an alternator, despite often being warned against jump starting. It must of course, happen but perhaps by clumsy use and leaving connected too long after initial start-up of flat bat car. That or connecting a small capacity vehicle battery to a much larger one or incorrect voltage. I bet a few numpties have used a 24v to 12v or 12v to 6v hook-up and fried some bits!

I was taught that you start the runner and then connect the battery up to the flat car and either let it idle for 5 minutes or hold the revs for @2-3k for 2 mins then try to start the other car, if it fails to start repeat the process one more time. If it starts disconnect promptly and if not kill the engine and get a bus.

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I was taught that you start the runner and then connect the battery up to the flat car and either let it idle for 5 minutes or hold the revs for @2-3k for 2 mins then try to start the other car, if it fails to start repeat the process one more time. If it starts disconnect promptly and if not kill the engine and get a bus.

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Thats just how i do it! (:

Alternators do whatever is required with their field current to attempt to keep their output voltage at its setpoint. No more, no less. RPM of the alt will vary the maximum available output current, but whatever is required by the starter of the sick vehicle will be supplied by the battery of the donor, not just the alt. I fail to see any mechanism for causing damage to the alternator by jump starting with donor engine running.

Edited 14 March, 201610 yr by Wino

Thats just how i do it! (:

must be right then lol

If in doubt I'll check Facebook, if it's on there it's gospel!

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Why oh why do people insist  on running the engine while trying to start the second vehicle, simple maths, your alternator puts out 95-100amps your starter motor uses 300-400 amps when turning engine over thus alternator trying to charge at 300amps  resulting in a damaged alternator perhaps not straight away but will eventually fail, nothing wrong in letting your car trying  to charge flat battery up that's what it's designed for  not the starter motor

 

It doesn't quite work like that. If you do it properly no damage should result to anyones vehicle. Best option to jump start someone safely is to wire it like the diagram below shows. On your vehicle use the top front suspension strut bolt or similar earthing point to clamp the neg lead to. Just keep it away from your battery. Only put the positive lead onto your battery. It's safer. Connect everything up before you start your engine. The starter on the non-working vehicle will draw the normal amount of current it needs through it's own battery and then of course, through the leads to your battery. No damage should result at anytime but best to keep your engine running at a very fast tickover so some extra juice is produced for the failed vehicles battery. Just make sure you monitor the jump cables to ensure they don't get too hot if repeated attempts to start are made. Use only good quality cables for the job. A van trying to start may draw more current than a car so heavy duty cables are best. Remember, everyone does this at their own risk.

 

Edited 16 March, 201610 yr by Estate Man

Plenty of modern vehicles have issues when being used to give a Jump Start to other vehicles.

 

I recently used a Hyundai to jump start a 2015 MINI.

I put the Positive cable across to the Mini Positive & the Negative from the Hyundai to the Earth on the MINI.

Left it a few minutes with both car engines off.

Started the Hyundai and let it run a few minutes, then started the MINI.  Easy.

Cables off and Hyundai switched off.

 

Then when i went in the Hyundai later, warning light and no power steering.

So read the Owners Manual, the bit on resetting procedure.

Thanked god i had not seriously messed up 2 peoples cars.

 

I will stick to using a booster pack and keep the jump leads for using on older vehicles.

Yeah...that's mostly likely because you went straight onto your battery with the neg lead. Always keep it away from the battery. But like you George, I prefer the battery booster pack method as like you say, modern cars are getting so complex now. Almost every car is a giant computer and we all know how easy it is to upset them!

It doesn't quite work like that. If you do it properly no damage should result to anyones vehicle. Best option to jump start someone safely is to wire it like the diagram below shows. On your vehicle use the top front suspension strut bolt or similar earthing point to clamp the neg lead to. Just keep it away from your battery. Only put the positive lead onto your battery. It's safer. Connect everything up before you start your engine. The starter on the non-working vehicle will draw the normal amount of current it needs through it's own battery and then of course, through the leads to your battery. No damage should result at anytime but best to keep your engine running at a very fast tickover so some extra juice is produced for the failed vehicles battery. Just make sure you monitor the jump cables to ensure they don't get too hot if repeated attempts to start are made. Use only good quality cables for the job. A van trying to start may draw more current than a car so heavy duty cables are best. Remember, everyone does this at their own risk.

 

Jumpstart.jpg

Well fair enough I can accept your comment but  as you quote "should be alright" I'd rather do it my way and make sure 100% that my cars  electrics are not damaged in any way, only just trying to be helpful as many people are not aware that damage can occur to their alternator or electric system,  as I said  the starter takes 3-400 amps alternator puts out around 100amps max it's not designed to run a starter just charge a battery  you cannot use starter and charge battery at the same time on your own vehicle

Well fair enough I can accept your comment but  as you quote "should be alright" I'd rather do it my way and make sure 100% that my cars  electrics are not damaged in any way, only just trying to be helpful as many people are not aware that damage can occur to their alternator or electric system,  as I said  the starter takes 3-400 amps alternator puts out around 100amps max it's not designed to run a starter just charge a battery  you cannot use starter and charge battery at the same time on your own vehicle

If there wasn't a battery in the donor vehicle, you'd be closer to being right, except the alternator in the donor vehicle still wouldn't be damaged because it will only give the maximum it can, and the starter motor of the sick vehicle may or may not have enough torque to turn its engine over with that amount.

 

But the donor vehicle does have a battery, which is what supplies the energy to the starter of the sick vehicle.

Well again fair enough  if you want to crap your system electrics so be it, been jump starting all sorts of vehicles for 40 years and never had any issues doing it the way I was shown as a lad, so will stick to doing it this way and know I'll not have any problems with my vehicle or someone else's if you wish to do it any other way that's up personal choice all I know is if you try and draw more amps than can be supplied somethings going to give

In 33 years as a tech and master tech I never once had a vehicle damaged in any way by using the method described in my post. Wino is correct in what he is saying. You cannot crap your electrics if your own vehicle used for the jump has a well charged battery and the engine is running at a smart pace. The alternator will only give the maximum amount of current it was designed to give. Nothing will be damaged!  I've started so many vehicles this way I cannot even begin to recount how many it actually is. Alternators will put out varying amounts of current and many cars will put out up to and sometimes above 130 amps. The main issue I found when I worked in the trade was folks connecting stuff up incorrectly and doing damage that way, or trying to start a very big 24v truck with a 12v car. It just won't turn the sick vehicles engine! Now that's not good! Main message is not to jump start someone if you don't know what you are doing.