Will jump starting from a running car damage my bike's electrical system?

Discussion in 'GS Boxers' started by VDRZANE, Jan 19, 2005.

  1. VDRZANE

    VDRZANE Salty Adventurer

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    This is a concern I have read about multilple times on this site and others, but have yet to see any suppporting documentation that prooves this theory. What is the issue, a higher amperage rating on the much larger car/truck battery?

    I just had to do my first jump start on my '03 GS Adventure the other day, and this topic came up.

    Thanks!
    #1
  2. charles960

    charles960 Been here awhile

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    I just ran two threads on this stuff. Read down a couple of threads about jump start and buying a battery charger. Lots of good responses to my questions.
    Charles
    #2
  3. VDRZANE

    VDRZANE Salty Adventurer

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    I've already read all of that stuff, thus my question.
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  4. Possu

    Possu de-nOObed!

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    There should be no problem as long as the jump leads are connected securely & correctly. Also ensure that neither vehicle touches the other.

    Connect & diconect the leads in the correct order to prevent spark.

    Connect: red/positive first.
    Diconnect: black/negative first.
    #4
  5. iillyyaa

    iillyyaa Adwrenchurer!

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    It won't damage the bike, but it may damage you if the hood support collapses while you're hooking the cables to the car.

    I never heard a plausible explanation for why jump-starting a bike from a car could possibly damage the former. Both have ~12V charging systems; with revs up and a working alternator both develop in excess of 14V and are designed to do that. You're safe to do it.
    --
    Ilya
    #5
  6. Loadedagain

    Loadedagain making chips

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    no problem at all. 12vdc is 12vdc. fly at er
    #6
  7. Guzz

    Guzz Gutless wonder

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    I'm always leary of jump starting a bike from a car ever since I fried the electrical system on an OLD Suzuki GS550L. But I've learned my lesson and now understand the reason why you DON'T just go battery to battery.

    Remember you connect in this order:
    1. Dead Positive
    2. Good Positive
    3. Good Negative
    4. Dead FRAME

    Also, if you can get by with it (when jumping a bike from a car), don't start the car. Try to get by with just the car battery.
    #7
  8. Finglonga

    Finglonga I got a BUSTED leg!

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    ...and for feck's sake NEVER use the accesory socket.:eek1
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  9. bmwmick

    bmwmick Old and Slow....Sorta

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  10. zouch

    zouch part-time wanderer Supporter

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    pshaw,... a starter system is only going to draw as much power as the starter requires, and that doesn't matter if it's from its own battery or another vehicles battery (through properly hooked up jumper cables). ideally, though, this should all be done without the 'donor' vehicle running.

    don't suppose we should even talk about having jump-started cars off of the GS here, now should we,...? :D
    (yes, i carry a set of jumper cables on the machine made up to fit into a plug that's hardwired to the battery for easier access... but i note that i've seen battery access points on some of the newer GSs since mine was built.)


    cheers!
    e
    #10
  11. Frank Warner

    Frank Warner Traveller

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    Added my comment to
    http://www.advrider.com/forums/showthread.php?t=66146

    so as to keep them all in the same place. !!!!

    But here they are again.

    Car electrics have the same limits as bike electrics - running the car motor will only increase the car battery voltage - it will NOT damage the bike/other car if the jumping car is running!!!!!!!!!!!!!!!!!!!!!! In fact the increased voltage (over a non-running situation) will help make up for the voltage drop across the jumper leads.

    If you make the last connection the earthy lead (negative) somewheres away from the battery - earth strap to the motor is good - then you should be away from any battery gas. Similarly the disconnet should be done away from the battery. If you are using the starter motor terminal then that would be OK too.
    #11
  12. ysr612

    ysr612 Long timer

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    the thing that I would worry about is the max charge rate of the bike batt as most cars are able to charge at 50 to 120 amps and most bike batts are not supposed to be fed current at over about 40 amps. or 10 amps over a longer time.
    #12
  13. xtphreak

    xtphreak from B4 "adventure bikes"

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    you're not charging the battery here, you're adding amperage to spin the starter on the bike

    the extra amperage will flow to the motor windings, that's where the lowest resistance is while you're starting the bike.

    there should be no problem with jumping the bike off a car battery if you connect / disconnect correctly.

    just like jumping another car.


    much adeiu over nothing





    ok I can't spell adeiu ... I ain't French thank Gawd
    #13
  14. Frank Warner

    Frank Warner Traveller

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    Furphy.


    To get 40 amps into a bike battery you 'd be well over 15 volts ...

    If the bike battery is under say 11 volts you may be a current surge into the bike battery from the car battery - but that will be of short duration .. and the running of the motor will have little effect on the surge current magintude (most of that will come from the car battery!).
    #14
  15. TurnMonkey

    TurnMonkey Face

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    What's the deal about connecting, disconnecting properly? I've never worried about any order of connecting or disconnecting. Thrash away :evil

    I've never had a problem, 31 years of life and jumping cars, never a problem. I'm not a mechanic by profession, so I'm not challenging those that are. It's just I've never heard of an issue like this......

    I have jumped my pickup from my lawn mower, how redneck is that!!!! :rofl :rofl :rofl
    #15
  16. xtphreak

    xtphreak from B4 "adventure bikes"

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    the issue is a hydrogen explosion

    your battery produces hydrogen gas ... it's flammable / explosive

    making the final connection CAN cause a spark,
    which CAN cause a hydrogen explosion,
    which CAN fu-k up your day as battery plates and sulphuric acid go flying

    making the final connection (neg) on the motor / ground strap / alt bracket / etc gets the spark away from the battery and that nasty hydrogen gas

    I have seen it happen and hosed down the unfortunate who it popped on
    #16
  17. TurnMonkey

    TurnMonkey Face

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    I understand the explosive issue and the last connect to a ground source away from the battery, but there was a prev post that listed this:
    Remember you connect in this order:
    1. Dead Positive
    2. Good Positive
    3. Good Negative
    4. Dead FRAME

    I did not understand significance of steps 1-3.
    #17
  18. Frank Warner

    Frank Warner Traveller

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    It should not be a problem if nothing goes wrong. If something does go wrong then steps 1 to 3 reduce/aviod the problem by providing a secondary safety barrier.

    1. Connect dead positive ; this has the lowest energy so is the least dangerous to have exposed on non connected end of the cable. Any spark should be small even if the exposed cable is connected to something.
    2. Connect good Positive ; removes the threat of step 1. No threat from any exposed ends as they are both connected.
    3. Good negiative ; Potential for sparking - if the other end of this cable is connect to something then this could spark - you want this connection away from the battery.
    #18