Jump Starting - Facts and Opinions

[Red Beard]

I'm just wondering what the facts, and opinions, are about jump starting cars.

The reason I ask is that I've had a couple of mechanics, and an auto sparky tell me not to, unless I've got proper surge protected leads, not the cheap and dodgy ones from auto chains. The risk of frying one of the many computers is too high, they say. Is this correct? or am I just being pedantic.

Some people get really annoyed if you say no. I just ask them if they'll pay to fix my car if something goes wrong, they never say yes.

And before anyone comments, I have never asked anyone for a jump start, I call my road service provider, and get them to do it, correctly, if required.

I'm guessing this may be divided on country city lines, jump starts being common out bush, due to the lack of road service coverage.

I know there's a lot of smart guys out there.

Has any one had a jump start go wrong?

Would you jump start someones car for them?

What leads do you use?

Thanks in advance.

[6.2L.Club]

$20 cheapo leads are fine if used correctly.

each situation and state of charge is different so to give one answer for all is difficult. eg, completely dead flat battery form leaving your lights on over night versus one where it winds over but not quite enough to start it.

Negative should alway be connected last and away from the battery on a good earthing point
Heater fan speed and lights turned on to help absorb any spikes in the system and the biggest thing is not to just chuck them on and crank it, leave them on there a while with the running car at 1200-1500rpm for 5 -10 mins to actually semi charge the flat battery to help reduce the current draw required to start the vehicle.

In the case of VE's, the stock calcium battery doesnt like to be heavily discharged and quickly recharged, it will reduce the lifespan of the battery and will not let you get a 100% charge unless it's trickle charged using a calcium type battery charger so unless you fit a deep cycle after market battery to your VE you would be better to put it on charge over night than to jump start it.

As you say, everyone has there own opinion but l have jump started 100's of vehicles over the years in the mining industry and all have PCM/ECM's and l have never had an issue using this method. I have also jump started other vehicles using my own including diesel 4WDs and never had an issue.

The amount of surge theat "good" or "cheap" jumper leads can absorb is very limited and worthy of 4/5ths of fark all. About all the are good for is telling the idiots that have no clue whether they have their leads on the wrong way or not. :lol:

[timy]

a guy from work was jumping one of the trucks (which uses a 24 volt system) and the battery literally blew up on him..

he was ok luckily but covered in battery acid, could quite easily have gotten in his eyes if not for a pair of sunnies..

anyway not to sure how he wired it up, although i do know that he connected to negative to the negative and not to an earthing bolt on the truck..

[awesome _vzss]

as posts above have said i have jump start a fair few cars with no problems wat so ever but positive always first ,then negative and make sure the other vechile has all it's loads turned of (eg lights ,a/c).
I have heard of ecu,pcm problems if the polarities are mixed up (positive to negative ,negative to positive)so that probably something you don't wanna get wrong

[Evman]

a guy from work was jumping one of the trucks (which uses a 24 volt system) and the battery literally blew up on him..

Depending on the type of battery it could have gone into thermal runaway

[VE SS Wagon]

I use my old jumper leads ive had for a while, I don't think type of leads really matters, more the technique, And always put positive on first as already stated and put the neg on a good earth on the car somewhere... not the battery, I guess so far I've never wrecked any of my cars computers although I've mainly jump started older cars...

[Evman]

The "Holden approved" method is also listed in the owner's handbook ;)

[VE SS Wagon]

The "Holden approved" method is also listed in the owner's handbook ;)

Yea but does that count? Only when you take it back in for warranty LOL then you did it The holden approved way :P

[LSXMAD]

LOL. What the f$%k.

[white lie]

a guy from work was jumping one of the trucks (which uses a 24 volt system) and the battery literally blew up on him..

he was ok luckily but covered in battery acid, could quite easily have gotten in his eyes if not for a pair of sunnies..

anyway not to sure how he wired it up, although i do know that he connected to negative to the negative and not to an earthing bolt on the truck..

24V systems can be tricky if you don't know whats going on. A lot of people I see with no 24V experience tend to get confused as the wiring goes from the negative of one battery to the positive of the next. Very easy for something to go wrong!

I've never had a problem jump starting vehicles but there are safe and not so safe ways of doing things. Provided you do it as said above, you shouldn't have any problems

[planetdavo]

The "Holden approved" method is also listed in the owner's handbook ;)

It really shouldn't be so hard for everyone to understand. :confused:
There are so many myths out there. Surge protected leads aren't really important. They are often recommended because most people are lucky to have opened their owners manual for more than 2 minutes in their whole life, hence have no idea how to connect them safely.

[cnnonyx]

Quick question on this topic.

To prevent damage, what is the correct sequence to attach jumper leads?

Dead car red
Charged car red
Dead car Black
Charged car Earthing point

????

Or am I totally off? I have jumped a lot of cars in the past, some with sparks, some without, I am sure every time I have done it, I have simply completed the task in a random and potentially dangerous order lol.

Clarification>?

[185iboy]

Wouldn't mind knowing this too, had to jump my vz 2 nights ago, it:bawl: blew a low beam globe

[white lie]

Make sure everything is off before you begin and the cars aren't touching. Especially with open doors or anything like that.

The positives don't matter so much, pretty sure the Holden manual says connect the good positive and then the dead one. Some people say the other way around just incase the lead flaps around or shorts somehow... Its less likely to spark off a dead battery.

Then good battery negative post to an earth on the dead car (not the battery).
I usually just go earth to earth and don't use the battery negative posts at all. Eliminates the confusion!

Some people say to turn everything on in the good car to drop the voltage down as much as possible before connecting the leads, but a lot of people get confused and turn everything on in the dead car, which will usually cause a spark as its trying to draw a lot of current as soon as you connect the lead. I just turn everything off on both cars, if there's very little current draw there shouldn't be a problem.

And as mentioned before, start the good car up and let it run for a few minutes before trying to crank the other one over.

[planetdavo]

According to that little book every new Holden comes with...
1- Red lead to positive (+) terminal of good battery.
2- Red lead to + terminal of flat battery.
3- Black lead to negative (-) terminal of good battery.
4- Black lead to a solid, metallic stationary point on the engine of the flat battery car.
DO NOT CONNECT DIRECTLY TO THE NEGATIVE TERMINAL OF THE FLAT BATTERY.
Note: VE's obviously differ, having the battery in the boot, but you substitute the jumper terminals in the engine bay as though they are the battery.

[White Rider]

Just bought some 700amp leads argh argh argh!

[cnnonyx]

Thanks PD - maybe I should have read the book that came with the car

[duke5700]

What is the reason for not connecting it to the negative terminal on the dead battery? I can't see the electrical difference?

[steve_t]

I'm not sure if it's the reason for not connecting to the neg terminal directly but one time this pizza delivery guy came and his battery died so he couldn't leave. The boys got out the jumper leads and upon connecting the neg to the dead battery last, the spark ignited the hydrogen gas being emitted and the battery exploded. For the VE, I'd imagine engine terminals for a remote battery (in boot or behind passenger seat in ute) would be the same as connecting to a chassis ground point, but someone else might know if there's a significant difference

[duke5700]

That makes sense, however hydrogen is only produced under charging conditions in lead acid. I think any chance of an explosion is to much of a chance hence the connection procedure. :goodjob:

[steve_t]

I think the hydrogen gas had been collecting in the battery for the evening. My old car's manual said when jump starting or charging, that you should remove all of the caps to allow the gas to escape more easily. Not sure if new batteries are different. Thinking about it makes me wonder about the battery under the carpet behind my passenger's seat :1peek: :)

[SLIPZ]

I bought a jump start kit and hid it behind a false panel in the boot install, charge it every few months and it has been fantastic, probably more for mates cars than my own.

Takes all the guess work out too as you can connect both leads to terminals then turn the jump pack on. This eliminates the chances of spiking and removes any risk to a 2nd vehicle.

It is effectively connecting a 2nd battery instead of a jump as such.


Highly reccomend it :)

[6.2L.Club]

That makes sense, however hydrogen is only produced under charging conditions in lead acid. I think any chance of an explosion is to much of a chance hence the connection procedure. :goodjob:


Wrong, large amounts of hydrogen gas are emitted when trying to crank your car with a dead battery, you connect the neg away from the battery as 9 times out of 10 you will get a small spark due to the current draw on the flat car, If you turn all your accessories off etc that current draw is minimized but due to the risk of still creating a spart you connect it away from the battery so it cannot ignite any gasses from the battery.

When charging a battery yes, it's a good idea to remove the cell caps if the battery has them as if they are blocked this can cause the battery to split open. If you ignight the hydrogen gasses with the caps off it will not explode due to the gasses being able to vent out the hole quickly, you blow the battery top off when the caps are on as the heated gasses cannot escape out of the vent quick enough so it simply blows the battery apart. It's not an explosion as such. I have seen an auto sparky demonstrate how safe batteries are by simply taking the vent caps off and lighting the hydrogen gas, there was a little flame and that was all. Safety is key to battery use and always remeber to wash everything off with water to dilute and neutralize the acid and the best method to clean coroded battery terminals is simply boiling water from the kettle for those that don't know. The spray that is put on terminals to prevent corosion is simply a barrier to block out the oxygen from touching the metal to prevent oxidisation (corosion).

[duke5700]

Wrong, large amounts of hydrogen gas are emitted when trying to crank your car with a dead battery, you connect the neg away from the battery as 9 times out of 10 you will get a small spark due to the current draw on the flat car, If you turn all your accessories off etc that current draw is minimized but due to the risk of still creating a spark you connect it away from the battery so it cannot ignite any gasses from the battery.

Ok if you really want to get technical while discharging and charging they will produce hydrogen and oxygen as electrolysis occurs between the plates in the battery. It is relative to the power throughput of the battery. Charging a battery from a low state to high over a longer period will produce much more gas than the power required to start a car. Hence when charging you remove your battery caps, you don't remove your caps when you start the car do you?

With a sealed battery the danger does not exist unless they have safety vents, however when charging them from a low state they require chargers with temperature compensation to alleviate the risk of over charging/thermal runaway etc etc.

Current does not produce and arc, voltage does. What you are experiencing is a what happens when a DC source is supplying the energy as DC does not pass through a zero state the initated arc is harder to extinguish. Once the air is "continually" ionised it provides a path much longer than with an AC supply. Shakey hands add to this.

Simply for the one in a million chance that the circumstances align for there to be enough hydrogen and oxygen present to create an explosion the battery procedure outlined by Holden is correct.

[6.2L.Club]

did that make you feel good did it?? man some people have big ego's :lol:

It's a hell of a lot higher chances the one in a million mate, get out in the real world and experience some things instead of having your nose in a text book, it will add a bit of character to your personality :goodjob:

and yes, if you want to attach the leads to the battery and you have removable caps on your battery, to make it idiot proof you can remove the caps when jump starting

and once again, it's not an explosion.....common wives tale told by text book junkies

[duke5700]

did that make you feel good did it?? man some people have big ego's :lol:

It's a hell of a lot higher chances the one in a million mate, get out in the real world and experience some things instead of having your nose in a text book, it will add a bit of character to your personality :goodjob:

and yes, if you want to attach the leads to the battery and you have removable caps on your battery, to make it idiot proof you can remove the caps when jump starting

and once again, it's not an explosion.....common wives tale told by text book junkies

Combine ego with being sick of morons in life and you get a bite everytime. Technical incompetence and because jo-blo told you so does not make it correct. Unfortunately for you I just happen to have real world experience to back up my qualifications.

I dunno but being an electrician by trade may well be living outside the text book? Hell I even worked on battery banks the size of semi trailers. This was lead acid and alkaline. They didn't magically blow up while changing connections or paralleling the banks? Not second hand info from someone who once talked to a car sparky 5 years ago and doesn't understand the concept :goodjob:

So how many battery fires have you see or even heard about? 3/5ths of 5/8ths of bugger all. You have more chance of being struck by lightning.

[planetdavo]

And people seem to think forum wars only ever involve the Davo...:lmao:
Time for some :love: fellas.

[seldo]

...the best method to clean coroded battery terminals is simply boiling water from the kettle... Another little tip - if you don't have any boiling water handy a can of Coke works brilliantly.

[XUV]

how did something so easy become so complex ......... must be a city thing ..... under the bonnet son ......

[HSVREDSLED]

I gotta flat battery a few months ago while holidaying.

Borrowed a set of jumper lead off old mate and connected positive to positive, negative on good battery and negative on earth/motor, I go around to crank the car and return to find old mate had removed the negative from the earth and placed on terminal. ARRRRRRRGGGHHHH!!!!!

Weird thigs happended. Fuel guage read zero when It was actually 3/4 full. A few other weird things I can't remember...anyway, ity fixed itself. All good now.

[Ellistwo]

What is the reason for not connecting it to the negative terminal on the dead battery? I can't see the electrical difference?


There is no difference, except connecting to the chassis is not as conductive (read as good) as connecting to the lug on the battery post. At least the leads from the lugs are connected to a good chassis bond, unlike a couple of teeth on jumper spring clamp that will arc and spit.

This thread seems to be loaded with folklore.

To the OP, just use a good set of leads that has a varistor wired across them to knock out spikes and connect battery post to battery post. To avoid splashing the clamps, go LIFO with one of negative leads.

[xthommox]

According to that little book every new Holden comes with...
1- Red lead to positive (+) terminal of good battery.
2- Red lead to + terminal of flat battery.
3- Black lead to negative (-) terminal of good battery.
4- Black lead to a solid, metallic stationary point on the engine of the flat battery car.
DO NOT CONNECT DIRECTLY TO THE NEGATIVE TERMINAL OF THE FLAT BATTERY.
Note: VE's obviously differ, having the battery in the boot, but you substitute the jumper terminals in the engine bay as though they are the battery.

Im not reading any further than this post on the first page as it's the only way to do it and has been for over 30 years of my driving. My old man explained it to me (he was an engineer), an auto electrician mentioned once to me also when I was about 18yo so it's been around that way for probably 50 years!!!! Why is this so fn hard to understand and why are there so many bloody ways (all wrong except for the one above) to do it!???

I give up. Just do it the way above and you'll be happy and please pass this onto your friends so we NEVER have to ask again.:)

[Red Beard]

I think I'll call time on this thread, all I wanted was to see if I'd been fed some bull, which I had, so nobody has fried their ECM, and as long as I control the leads, I'll be happy to give someone a hand. Yes some people did have some slight differences in procedure, but not enough to do any damage.

Thanks to all.

Dave.

[6.2L.Club]

So how many battery fires have you see or even heard about? 3/5ths of 5/8ths of bugger all. You have more chance of being struck by lightning.

I have physically seen about half a dozen, have seen the results of a dozen of so more (working opposite shifts) and heard of a couple of dozen happen in my time as a fitter. If that many people were getting struck by lightning where you live, l suggest you move somewhere a little safer :lmao:

I guess being 26 with an ego, and being a high voltage sparky makes you an expert in DC extra low voltage automotive applications aswell :goodjob:

No matter what your text book tells you, current draw causes sparking
ie.
connect to batteries with the same voltage and same amount of charge - no spark

connect one good battery to a flat battery, as current transfers to the other battery a small spark occurs

Connect a good battery to a starter motor as youyr trying to crank it and watch the sparks fly as your trying to draw 600 or so amps into a big 24v starter on a diesel.

Yes l understand that "technically" voltage causes the spark (voltage pushes amps through ohms) but without the current draw there would be no spark. :rofl:

[MJR-57T]

Simply blow all the hovering gas away before connecting :rofl: :rofl:

Is there a difference between placing a new charged battery into a car and hooking up the terminals verses hooking a charged battery from another car to a dead battery.
I get a spark every time i reconnect the neg terminal if I've been doing work with the electronics and I'm still here.
Im not saying that post to post is the correct way but maybe the "neg to engine ground" is there to safeguard against those who have no idea. Hooking directly seems ok if done the right way.

[6.2L.Club]

Simply blow all the hovering gas away before connecting :rofl: :rofl:

Is there a difference between placing a new charged battery into a car and hooking up the terminals verses hooking a charged battery from another car to a dead battery.
I get a spark every time i reconnect the neg terminal if I've been doing work with the electronics and I'm still here.
Im not saying that post to post is the correct way but maybe the "neg to engine ground" is there to safeguard against those who have no idea. Hooking directly seems ok if done the right way.

There is no right way to hook it onto the battery :confused:

has alot to do with a little luck and alot of common sence which doesnt seem that common these days:rofl: