Motorcycle Forums » Sport Bikes

Battery's

  • February 3, 2010 5:04 AM PST
    I recently had a problem with my bike, due to financial reasons I been limited to travel. Cruising to the store and back going slow and easy for a while I found myself with a dead battery at the gas station. When I got home I read the manual charging system and saw that the alternator doesn't even kick in till 4000 rpms. All thse short trips running the headlight on did it in.

    I charged the battery for half day and started it up, put a volt meter across the terminals and sure enough idling was just on 12.5 volts. I slowly brought the throttle up and near 4000 rpms the voltage shot to 14.5 where it should be running.

    I recommend checking your battery like this to see where your alternator starts at to save you from an unpleasant situation if you haven't done so yet. A bikeweek event is prime condition for loosing a battery due to poking along in traffic.
    • Moderator
    • 1362 posts
    February 3, 2010 5:09 AM PST
    Always check your terminals to make sure there are tight. A battery tender will save your battery. I always plug my bike in.
    • 1781 posts
    February 3, 2010 5:53 AM PST
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon
  • February 3, 2010 5:58 AM PST
    nightdragon wrote...
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon

    You don't have a horse ????   
    • 0 posts
    February 3, 2010 6:54 AM PST
    Just take a wire and jump the terminals. You can tell how good the battery is by how good the spark is..









    (yes that is a joke! Please do not do it!)
  • February 3, 2010 7:05 AM PST
    What rpm does the typical newer Harley start charging at, 2000, 3000..?
  • February 3, 2010 9:36 AM PST
    I never knew that the batteries were not getting charged at low RPM. Thanks for the info.
    We keep all of our bikes plugged into battery tenders over night. We noticed the batteries last much longer with the tenders.
    • Moderator
    • 15697 posts
    February 3, 2010 9:50 AM PST
    Flatlander wrote...
    What rpm does the typical newer Harley start charging at, 2000, 3000..?

    I am not an official mechanic but...

    Any good alternator should be putting out enough voltage and current to charge the battery around 1000 to 1500 rpm, even with a full load ( all lights and accessories on). Of course the current will increase with rpm and you will get a better / faster recharge while driving at higher rpm. Since most Harleys run at lower speeds you should not have any problems assuming your other electrical components are working correctly.

    Here is a quick way to see if this is true...
    shine your headlight on a close surface (like a garage door) at night. Have the engine warm enough that it will idle without enrichment or choke. You FI guys just be sure it is fully warmed up. Then slowly increase the throttle and if the headlight gets appreciably brighter I would have it tested by a mechanic or go get your meter and shop manual.

    I did a little more research...
    http://www.hdtalking.com/electrical_and_lighting_systems/741-testing_the_charging_system.html />
  • February 3, 2010 9:55 AM PST
    nightdragon wrote...
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon



    I'd like to hear what Angel Eyes has to say after you do this little trick!!
    • Moderator
    • 15697 posts
    February 3, 2010 10:00 AM PST
    sidetrack wrote...
    nightdragon wrote...
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon



    I'd like to hear what Angel Eyes has to say after you do this little trick!!


    Dragon, If you can do that you are probably very popular.

    • 1781 posts
    February 3, 2010 10:06 AM PST
    OK maybe I stretched (get it) the the truth a bit
    Dragon
    • 904 posts
    February 3, 2010 10:21 AM PST
    laughed so hard I think I cracked a rib. *lol*
  • February 3, 2010 10:52 AM PST
    not goin there dragon, hope your rib heals quickly adventuregirl
  • February 3, 2010 10:53 AM PST
    I use a tender in the winter when I can only get out very rarely. In the summer I have NO problems with the battery staying charged. Even if I just do lots of short little runs for a couple of weeks.
    • 1 posts
    February 3, 2010 11:36 AM PST
    Flatlander wrote...
    What rpm does the typical newer Harley start charging at, 2000, 3000..?

    As far as I know, Harley's are charging any time the engine is running.  Now at very low RPM they may not put out enough to run the accessories and chagre the bike, but they are putting out current.

  • February 3, 2010 12:09 PM PST
    Deader statement--"--at highway speed will take 2 miles to bring battery to full charge after cold start." That is for 2005 Suzuki Bulivard C90 with low beam and Driving light Bar on. Turn the Driving Light Bar off wii be ok after 1 mile. Gel Cell Battery

    Some people just get recharged in differant ways..???
    • 1160 posts
    February 3, 2010 1:06 PM PST
    nightdragon wrote...
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon



    All I can think of is Dragon trying to use his Tongue to see of the battery is good.....

    LOL

    Seakers
  • February 3, 2010 6:48 PM PST
    Digital voltmeters are your friend, can do so much with them, damn good tool for the money, $20.00 +or-. Every alternator and generator has a voltage regulator in line either internal or external, the volt meter will tell you when it clicks on, all different. I was surprised to see mine come on at 4000 rpm.
    • 66 posts
    February 3, 2010 8:54 PM PST
    nightdragon wrote...
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon

    Dragon youve either a little battery or watch out girlz
    • 1510 posts
    February 4, 2010 7:56 AM PST
    nightdragon wrote...
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon

    I perfer alligator clips attached to my ear lobes then attached to the battery!

    Clears my sinuses!

    Short rides that do not let the engine reach operating temps for a sugnificant amount of time will cause a moisture buildup with in your crank case also which will play havoc on polished machined clearenced parts (example: cam, main bearings crankshafts etc.) Stay in a lower gear longer to keep RPM higher and Increase temps. to disapate moisture.
    • 6 posts
    February 5, 2010 9:07 AM PST
    nightdragon wrote...
    I like sticking my tongue across the two terminals of my motorcycle battery to see if it is good.
    Someone will get this eventually

    Dragon

    NO, NO, NO - You got it all wrong!
    You have it confused with timing an engine.
    Back in the day they way to time an engine was to:
    1. Disconnect the #1 plug wire, pull the boot back & insert the plug wire in your left ear.
    2. Hold a flashlight in your teeth
    3. Grip the #1 plug w/ your left hand
    4. Start the engine

    Then look @ the timing mark. The voltage kick would cause your eyes to blink every time the #1 plug fired
  • February 5, 2010 9:14 AM PST
    I want to get a RAT my Heritage. Can probably pick up a suprlus one off an old Intruder pretty cheap. (if you are an ex-airdale you will know what this is) Should charge plenty good at anything over 300 miles an hour.
    • 8 posts
    July 20, 2010 1:39 PM PDT
    GaryTJ wrote...
    Just take a wire and jump the terminals. You can tell how good the battery is by how good the spark is..









    (yes that is a joke! Please do not do it!)

    Actually that is just what I do to test lead-acid batteries to see if there is a damaged cell. The temporary short makes a damaged or faulty cell create extra bubbles and they will be visible thru the white opaque plastic.