19 replies to this topic

[adrian91889466]

Hi Friend,

 

My VX220 got flat battery.

I noticed the battery location is not that easy for jump start.

May I know is there any easy way to jump start my VX220?

I have the cable and battery.

 

Thanks!

Adrian

[Baron Von Scubadaddy]

be carefull u may blow the ecu

do a search and find the correct way to do this

 

it may be safer to extract the battery and charge it or replace it with a new one

 

 

I have had a blown ecu due to jump starting I can't explaine why or how just that I did !

 

 

[Zoobeef]

Lift out the screen wash bottle and then you should get the cables down there. Or find another decent earth point for second cable.

[Rickwoo118]

Can't you just connect a Ctek charger to it and leave it overnight and it will be fully charged. You can connect one of these through the cigarette lighter socket as well which makes it easier.

[turbobob]

I've still yet to figure out how it can blow the ecu when connecting another 12v source in parallel

[Baron Von Scubadaddy]

me too and I'm electrically trained ...but it's what happened to me when I got jumpstarted at home by the AA a few years back

Ireally wish U could understand it

I don't know if its an ignition on or off type thing

but basically the car went flat

the aa jump started it

that failed

it went to dealers

then needed new ecu

 

 

[ianrm]

I had a flat battery last year and my trickle charger wouldn't bring it back to life. I left it over night on normal charger and it came to life. I have also bump started a few VX's with no issues.

 

[Baron Von Scubadaddy]

http://www.vx220.org...hl=\jump start\

[Gedi]

AFAIK, it's to do with disconnecting the jump leads. The car with the flat battery sees the massive drop in voltage when the leads are removed, which can result in the alternator producing a spike in voltage which can fry the sensitive components.

 

My beemer has jump start points which protect against this.

Edited by Gedi, 17 February 2014 - 08:17 PM.

[turbobob]

It won't be a voltage drop as the alternator will be kicking out about 14v. However there will be a change in load on the alternator when the jump start battery is removed. I'm just pondering the implications of load change.....

[Zoobeef]

On some of our trucks you have to keep the slave lead connected for about half an hour after jumping a dead vehicle to protect the dead vehicles alternator. Similar thing?

[smiley]

I had a flat battery last year and my trickle charger wouldn't bring it back to life. I left it over night on normal charger and it came to life.

 

I believe the ctek needs to detect some minimum voltage to start trickeling.

A way to trick it is to connect the dead battery to a full one, attach the ctek, and when it starts to trickle, remove the wiring to the full battery.

[Chris P Duck]

Got to admit I don't understand it either (BEng Honours degree in electronic engineering) When connecting the jump leads surely there's less of a change in potential difference than installing a new battery?

It won't be a voltage drop as the alternator will be kicking out about 14v. However there will be a change in load on the alternator when the jump start battery is removed. I'm just pondering the implications of load change.....

Voltage drop (and load change) will be less than a battery terminal coming loose, which whilst it hasn't happened to me I understand it does happen. Not doubting it happen(s) just can't get my head round how!

Edited by Chris P Duck, 17 February 2014 - 09:17 PM.

[Gedi]

It won't be a voltage drop as the alternator will be kicking out about 14v. However there will be a change in load on the alternator when the jump start battery is removed. I'm just pondering the implications of load change.....

 

When the good battery (+ alternator) providing 14v is disconnected, the alternator on the flat vehicle can create a voltage spike as it tries to compensate for the huge increase in load.

 

It's called a load dump http://en.wikipedia.org/wiki/Load_dump

[turbobob]

If anything there will be a slight increase in voltage with the extra load removed. But the regulator will stop any overvoltage. Maybe it's sh*t regulator and there is a momentary back emf spike although I find this hard to believe.

[deano01]

I jumped started mine yesterday, which would of been about the tenth time I have used the jump leads to start it. Had no issues so far.

1) Just make sure the cables don't touch the chassis.

2) Make sure ignition is off whilst connecting cables up.

 

The vehicle I use to jump start I don't have the engine running. Don't know if that makes a difference.

 

Battery is now connected to c-tec, a bit late I know.

[ghand]

Got to be some voltage spike maybe due to the arcing as you remove or attach the leads possibly? some inductive component or other. I think it's just bad luck and generally should not happen, Push started mine a few times, if the ignition lights come on its so easy to bump start I couldn't be arsed waiting for it to charge or faffing about with jump leads. .

Edited by ghand, 17 February 2014 - 10:42 PM.

[Notalotus]

It is a voltage spike that occurs for a few milliseconds prior to the regulator getting it under control. If the leads are left connected with the donor vehicle running for several minutes before attempting to start the engine it should be okay. We build in protection to our tracking systems to save them in the event of jump starting. To give you an idea of the levels, protection kicks in at around 72 volts.

[turbobob]

How can leaving the leads connected several minutes before make a difference? Do you have an oscilloscope trace of this spike?

[Notalotus]

The spike is caused by the load of the flat battery and occurs when the alternator spins fast enough to start charging. Letting the flat battery take some charge from the donor vehicle, five minutes should be enough, reduces the load enough to minimise the chance of a huge spike. I've not put an oscilloscope on when jump starting, but I've seen a diagram produced by Iveco on their bodybuilder website. Newer vehicles with 'intelligent charging' don't start charging for quite a while after the engine starts. Even then the voltage rise is quite slow. I wonder if this would damp out the spike?