everhopeful Posted February 26, 2012 Share Posted February 26, 2012 Does anyone know the correct procedure for jump-starting an X 250 from another vehicle? My Peugeot handbook only deals with using a spare battery, and even then contradicts itself by saying I must disconnect the battery with the engine running, but must not disconnect the battery until 2 mins after switching off the ignition! Looking at various websites, the sequence of cable connecting/disconnecting seems consistent, but some say to disconnect the cables with both engines running, and others insist engines must be stopped. The penalty for getting it wrong is of course destroying the electronics/alternator of either or both vehicles, which is why I'd rather not guess! So, if I've got it right - Connect red lead to + of dead battery (X250 + stud under bonnet). Connect other red lead to + of good battery. Connect black lead to - of good battery. Connect other black lead to metalwork (X250 earth bolt) of dead vehicle. Leave to stabilise for a few minutes. Start donor vehicle and run at fast idle for a few minutes. Leave donor vehicle running and start dead vehicle. But then what is the correct way to close down and disconnect? Link to comment Share on other sites More sharing options...
ChrisK5 Posted February 26, 2012 Share Posted February 26, 2012 Disconnect both negative (black) terminals first, then both positive (red) terminals second. Link to comment Share on other sites More sharing options...
everhopeful Posted February 27, 2012 Author Share Posted February 27, 2012 Thanks ChrisK5. My main confusion is WHEN to disconnect. Do I disconnect with both engines running, or run for a while to charge the flat battery, then stop both before disconnecting? Link to comment Share on other sites More sharing options...
kelly58 Posted February 27, 2012 Share Posted February 27, 2012 If I had a flat battery and was near a power piont I would connect the EHU cable to the mains and switch the charger to VEH Batt and wait for it to charge up. I had to once when I had left the interia light on and run the Veh battery down. Link to comment Share on other sites More sharing options...
WhiteCheyenneMan Posted February 29, 2012 Share Posted February 29, 2012 Not had to jump start my Ducato...........yet. But done many cars and even my lawnmower! I always start donor vehicle and then connect flat + to donor +; donor - to flat - and leave to run for a few minutes to get a trace of a charge in the flat battery. Then start flat vehicle and disconnect cables in reverse. Leave both vehicles running, turn off donor after about 5 mins if not required. Take flat vehicle for a run of at least 20 miles. If you turn off flat vehicle after starting it, it probably won't start again!! It takes about 15mins, with engine running, for a battery to regain the charge required to start an engine. Link to comment Share on other sites More sharing options...
everhopeful Posted February 29, 2012 Author Share Posted February 29, 2012 Thanks for the comments. Unfortunately my onboard charger won't connect to the vehicle battery, so when I'm flat it 's out with the jump leads. Disconnecting with both engines still running seems to be the most popular method. BUT, why do the AA - who you'd think would know - say on their website "Don't remove the jump leads while the engines are running as this can cause serious damage to the electronics on either car"? Link to comment Share on other sites More sharing options...
WhiteCheyenneMan Posted February 29, 2012 Share Posted February 29, 2012 The AA? What do they know (lol)When my brand new car had a flat battery in 2009 (2 x loose earth cables by factory), the AA Technician, having sorted out the earth leads, jumped the car and said "Don't turn it off, take it for a good run!" and he disconnected the leads. He's a technician, he didn't write the web site *-) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 1, 2012 Share Posted March 1, 2012 WhiteCheyenneMan - 2012-02-29 10:54 PMThe AA? What do they know (lol)When my brand new car had a flat battery in 2009 (2 x loose earth cables by factory), the AA Technician, having sorted out the earth leads, jumped the car and said "Don't turn it off, take it for a good run!" and he disconnected the leads. He's a technician, he didn't write the web site *-)Received wisdom nowadays is that one does not connect batteries on a negative-terminal to negative-terminal basis when jump-starting vehicles. In fact, with certain vehicles (like 2000-onwards Transits) it would be very difficult to directly connect battery-to-battery as the Transit starter-battery is not housed in the engine compartment.Personally (and I've jump-started plenty of vehicles during my 50 years of driving) I would not start the 'donor' vehicle's motor until I had connected the jump-leads to the 'recipient' vehicle, as much as anything because I can't see any benefit in doing this and I can envisage a potential risk.Ford's Transit Mk 6 jump-starting instructions advise that, after the recipient vehicle's motor has been started, both vehicles' motors are run for a minimum of 3 minutes before disconnecting the jump-leads. Ford's advice is to then "Disconnect the leads in the reverse order" (ie. negative then positive). No Ford advice is given regarding whether either, both, or neither of the motors should be running when the leads are disconnected, though there is a warning that headlights should not be switched on when disconnecting the jump-leads as the peak voltage could blow the bulbs. If the recipient vehicle's battery had some charge in it to begin with (just not enough to start its motor), then it should be possible to restart that motor after a few minutes of running with the jump-leads connected. In such a scenario both motors could then be stopped, the jump-leads removed and the recipient vehicle's motor should restart OK. This is the procedure advocated by the AA.However, if the recipient vehicle's battery was originally really flat, then it will be necessary to keep the recipient vehicle's motor running during the jump-lead disconnection process. In that scenario, if the recipient vehicle's motor were stopped and the jump-leads disconnected, there's a strong likelihood (as WCM says) that the motor won't restart and the jump-starting procedure would need to be repeated. The AA warns against jump-lead disconnection with the motor(s) running but, in reality, there may be no choice. Link to comment Share on other sites More sharing options...
hallii Posted March 1, 2012 Share Posted March 1, 2012 It's the sparks that make spikes that destroy the electronics. To make sparks between two batteries you need two different voltages, the more different they are the more likely it is you will get a big spark. Running engines for a while brings the voltages up to somewhere nearer each other thus avoiding the big spark. Personally, with ECUs costing up to £1000 I simply won't do it. It is safer to remove the battery and charge it with a charger if you can't charge it "in situ". For some reason the donor's electronics are the ones that suffer, (I am advised, I have never experienced that), So don't try and get a jump start off me when camped at some site or another. I will (and have) refuse, very sorry etc. but that's the way it is. H Link to comment Share on other sites More sharing options...
everhopeful Posted March 2, 2012 Author Share Posted March 2, 2012 Thanks all for your help with this confusion. From what's been said, my understanding now is - If possible avoid jump-starting and charge instead. If it's likely that the dead motor would restart after a period of running then disconnecting with both engines stopped would be safer. (The ECU's are safer by being off) If the dead motor must be kept running then wait a good while to equalise the voltages of both vehicles and then disconnect whilst running. This is slightly riskier but if the voltages are virtually equal then little sparking would occur. I would only be jump-starting from my own car and can fully understand any unwillingness to take risks for a stranger. Using a charger seems to be frowned upon by some manufacturers and they recommend disconnecting the battery first. Is this really necessary though? I can see that a high voltage fast charger would not be a great idea, but would a simple trickle charger pose any hazards with the battery still connected? Is this the equivalent of inbuilt chargers or do they do something more complex? Link to comment Share on other sites More sharing options...
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