Announcement

Collapse
No announcement yet.

Dangers of Jump starting

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Dangers of Jump starting

    I wanted to create a seperate post for this due to importance.

    This may be common knowledge but I have to admit I wasnt aware of it.

    One of the most expensive parts that was replaced on my MC recently was the ECU. The guy said this had likely been damaged by jump starting it (which I had been doing alot with recent battery issues).

    Has anyone else heard of this? Obviously if you ever do get battery issues and you need to jump start it I assume there is a proper procedure that needs to be followed? Perhaps in the handbook?

    Also, I prefer not to take mine out in the winter but now worried that if I leave it too long that I might get more starting problems, I dont have a power point in my garage so cant use a trickle charger. Suppose I will just need to start it up every couple of weeks.

    Does anyone else store theirs away for the whole winter?

  • #2
    I've heard this a lot before, for any car with an "ECU" so really dating back to the 80s. I can only think it's the voltage spikes from the other car or interference from the other car that may damage the ECU? I've jumped mine a few times from various cars and it's been ok.

    Used mine last week having not used it for 6 weeks and it started as normal (new BOSCH Silver battery seems to be great!)

    Best thing to do is to have the battery on trickle charge I suppose.

    Comment


    • #3
      my handbook (1999 s50) does say you can jump start the z3m from another car, but does give precise instructions on how to do this, I have done this many times without any problems as my coupe can be unused for months at a time, I also have invested the small amount in a trickle charger.

      Comment


      • #4
        I mean, if there was an issue then why give you big hefty jump start terminals under the bonnet?

        Comment


        • #5
          fair point but after googling the problem seems to be an issue that seems to be well known unless a false myth

          http://www.bimmerinfo.com/jump_starting_your_BMW.htm

          Comment


          • #6
            Originally posted by siwilson View Post
            I mean, if there was an issue then why give you big hefty jump start terminals under the bonnet?
            So that you can fix a trickle charger and lock and alarm the car without having to lift the boot floor, undo and remove the battery cover and leave the rear door open and car unlocked and un-alarmed when charging.
            /// Exdos ///
            "Men who try the impossible and fail spectacularly are infinitely superior to those who reach for nothing and succeed" --Napoleon Bonapart

            Comment


            • #7
              As you have no power socket,either remove your battery completely and take it nearer your house,or try one of those solar panels which you plug into your cigar lighter socket i dont know how good they are but worth a try!

              Comment


              • #8
                Mines in the garage at the mo having a few bits done and while I've trickled the battery its still caput.

                They did show me how to jump start it correctly - theres a point under the bonnet at the left hand side to take off a cover for the positive and do it form there. I was warned doing it any other way could cause big issues.

                Comment


                • #9
                  Originally posted by exdos View Post
                  So that you can fix a trickle charger and lock and alarm the car without having to lift the boot floor, undo and remove the battery cover and leave the rear door open and car unlocked and un-alarmed when charging.
                  Possibly, but they are referred to as jump start teminals, not charging terminals and way overkill for trickle charging. Even the owners manukla describes the 'approved' jump start pricess in detail.

                  I suspect this is another case of a few cars being damaged and motor manufacturers leaving the poor owners to carry the can rather than incur the cost or a redesign or recall.

                  Comment


                  • #10
                    I started having battery issues recently. The original battery had lasted for 8 years so can't complain. I had to jump start it several times until I replaced the battery and had no issues.
                    The only problem I had was with the bloody alarm when I opened the car with the key, when the battery was flat. The alarm must have its own power supply as it kept going off even with the car battery disconnected in the boot.

                    I replaced my battery with a Varta E44 (short code) 77Ah. I was going to get the Varta E39, but this is a bit pricey.

                    Comment


                    • #11
                      It might be from the risk of damaging the ECU if the terminals are put the wrong way around and shorted, on old cars this probably wouldn't do anything but on "modern" cars could fry something sensitive?

                      Comment


                      • #12
                        Originally posted by c_w View Post
                        It might be from the risk of damaging the ECU if the terminals are put the wrong way around and shorted, on old cars this probably wouldn't do anything but on "modern" cars could fry something sensitive?
                        You read similar horror stories about people using welders on cars. The scare used to be that the alternator would get damaged and now this also includes the ECU. From what I've read on the subject, it seems that you need to ensure that your connections on the car are clean when attaching the leads and that you don't create sparks and short circuits when making the connections.
                        /// Exdos ///
                        "Men who try the impossible and fail spectacularly are infinitely superior to those who reach for nothing and succeed" --Napoleon Bonapart

                        Comment


                        • #13
                          here's a article from the BMW car club magazine which makes interesting reading,

                          Comment


                          • #14
                            You can do a simple battery change without getting into any of those problems!! Maybe it's a US thing!?


                            Originally posted by exdos View Post
                            You read similar horror stories about people using welders on cars. The scare used to be that the alternator would get damaged and now this also includes the ECU. From what I've read on the subject, it seems that you need to ensure that your connections on the car are clean when attaching the leads and that you don't create sparks and short circuits when making the connections.
                            Yea I think with welding it's highly recommend to disconnect the battery as you're sending high current through the body which "may" affect stuff like ECUs.

                            Comment


                            • #15
                              My sister has a 09 plate X5 and she has had lots of problems due to flat batteries/ the battery being disconnected.

                              She returned from holiday and had a flat battery (left an interior light on). BMW road assist sent out a 'technician' who did not even know where the battery was.....after a lot of phone calls he found the battery (although i presume he could have used the under bonnet terminals) and tried jump starting it...... roll on lots of sparks, scared kids etc.

                              Ended up started buy with numerous problems, loss of sat nav, radio, windows going up and down by themselves etc...... took it into dealer who tried charging her for sorting it out as it was caused by owner error (flat battery).

                              More recently the battery was disconnected again in a body shop, when reconnected had lots of gremlins.

                              I am sure the MC is not very sensitive to disconnecting the battery but these new models have issues with it for sure.
                              S50 Black, H&R Arbs/ Springs, B8s, Larini Exhaust

                              Comment

                              Working...
                              X