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how do i tell if a motorcycle battery is dead?

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by daedalus, Nov 6, 2011.

  1. it goes completely flat after 1-2mth of not using

    i can charge it up again (~12hours) and then it works

    but after 1-2mth it goes flat again.

    does that mean its dead and i should replace it?

    its a no brand about 2.5years old


     
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  2. My bike does the same thing. I found that if I use the kill switch as well as turning off the ignition then the battery stays charged. So for me, I think I have a small battery drain.
    Electricity is like black magic to me, so I have no idea how to narrow down where it may be.

    You may have a similar problem.
     
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  3. normal for a bike battery if you don't ride the bike for that long
    some people hook up trickle chargers if their bike is going to be of the road for that long.
     
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  4. +1 to Spenze you more than likely have a small drain current of some description. If you know you are not going to use it for a couple of months disconnect the battery and then reconnect and try next time you are going to use it. This will show if it is a battery with an internal fault or a bike drain. A certain amount of self discharge is inevitable though.

    If the bike has infrequent use then it may be worth getting a maintenance trickle charger.
     
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  5. And letting it go completely flat is likely to stuff it. Each time it goes flat it dies a little and sooner or later that is goingto be it.

    Easiest thing is to use it more often.
     
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  6. :) :) +1
     
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  7. what voltage is on the battery when it is disconnected from all loads and chargers? You should get about 12.4V minimum, 12.7V normally.

    For a fully comprehensive way to test:

    Battery trouble shooting guide
     
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  8. Holding charge for a month or so isn't too bad. When it can't start the bike after a week of non-use I'd be worrying.

    Mind you, I just pulled the tarp off the Ural last weekend, expecting a good case of flatness and the old Russian Hammer fired on the first compression after more than 4 months of dormancy :D. That's a 3+ year old battery that has received no maintenance during its life.
     
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  10. How do i tell if a motorcycle battery is dead?

    20min of CPR, if it doesn't start breathing its dead.



    Be careful of acid burns, they're painful on the lips.
     
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