Can You Jump Start Modern Cars.?

[Liam40]

Hi Everyone,

This maybe a totally stupid question but I’m going to give it a try, lol.

Can you start modern cars with jumpleads, what with all their modern electronic computers and circuitry on board.?

 Liam.

[alexp999]

I was just told by a neighbouring mechanic to make sure that the donor car isn't running, but otherwise do it as usual.

[TomsFocus]

You CAN yes, but it's far better to charge the battery instead if possible.

Jumping can create spikes and cause electrical issues on both cars.  It's mainly dash screens that get fried on the Focus', most people get away with it but obviously not a cheap fix if it does happen.

[pragmatix]

Yes but take care, I always leave the side lights on, on the car that being jumped started, this is supposed to smooth out any spikes, allways worked on Citroen C5s and Mondeos.

[Stoney871]

Also never clip the negative cable to the battery, always to a bare metal body part to avoid power spikes.

Sent from my SM-G965F (S9+)

[Stoney871]

Of course another option is a decent booster pack, the voltage is more regulated and stable.
Halfords do a decent one, had one of these for years and it does a decent job.

https://www.halfords.com/workshop-tools/garage-equipment/battery-chargers-jump-starters/phaze-4-in-1-jump-starter

Sent from my SM-G965F (S9+)

[Micro]

On 3/5/2019 at 1:47 PM, Stoney871 said:

Also never clip the negative cable to the battery, always to a bare metal body part to avoid power spikes.

Sent from my SM-G965F (S9+)
 

That's actually to prevent sparks igniting the hydrogen gas potentially discharged from the flat battery when it's charging.

Modern car electronics will be (should be!) suitably protected with filters and whatnot on power supplies for things.

[Turvey]

What about the good old-fashioned skill of bump starting cars? 

 

Only available in manuals of course and preferably with a hill as well 😀

[alexp999]

5 minutes ago, Turvey said:

What about the good old-fashioned skill of bump starting cars? 

 

Only available in manuals of course and preferably with a hill as well 😀

Pretty sure the handbook of most modern fords (and probably other manufacturers) say not to bump start them.

[iantt]

Jump pack is the best of the worst. 

I like mine. Use it 10 + times a day then recharge overnight.

[Turvey]

1 hour ago, alexp999 said:

Pretty sure the handbook of most modern fords (and probably other manufacturers) say not to bump start them.

Really? I wonder why? 

I used to have a Cortina Estate MANY years ago that I bought for £20, didn't have a starter motor, so had to park on a hill or make sure I had a couple of passengers willing to push 😁

[TomsFocus]

Bumping is such a bad idea nowadays lol.  Puts a lot of strain on the drivetrain, definitely not good for a dual mass flywheel or weak clutch/gearbox (which are fitted to a lot of small, cheap cars these days!).  You're also rotating internal engine parts and the HP fuel pump without sufficient lubrication until the engine actually starts, causing metal on metal contact and excess wear on all of those parts in the process.  

On a basic old car it's fine but I really wouldn't recommend it on anything modern unless you have absolutely no other choice.

[eddie eastwood]

Neat petrol into the cat/convertor