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Converting 12V Battery to 6V

Discussion in 'Technical and Troubleshooting Torque' started by Lachiepower0402, Jun 9, 2015.

  1. Not sure if this is the correct sub-forum, feel free to move the thread. Anyway,

    I have a Yamaha DT 175 1992. The bike when I got it, did not have a working battery, the 6V battery was reading less than 1V. It was a 6N6-3B-1. So I was thinking, of dropping the voltage on a 12V battery I have to 6V for the bike.

    First of all would this be possible and how would I go about doing it. e.g. voltage regulator, resistor, DC/DC converter, etc.

    The battery is only used to power lights, horn, etc. The bike can run with no battery and use lights, horn, etc. But the horn sounds terrible and the lights dim in and out depending on RPM.
  2. You can convert 12volts down to 6volts relatively easily if you don't need to run an electric starter motor. Your problem is the alternator will only charge a 6volt battery.

    There is a discussion on how to convert a DT175 to a 12 volt system HERE that may be a better option.
  3. That looks like a very interesting thread, but I don't use this bike that often as it is not at my place, but at my friends house and i only ride it when I go up there. I was just looking for a simple fix.

    I don't mean to seem like I don't care, because I would definely do that if I had the time and money. Thanks anyway. :)

    I don't mind that the bike will not charge the battery, because like I said, I don't use it very often, so I could charge the battery after I use it.

    Would you be able to tell me how to get the 12V down to 6V and will it be safe to run this, i.e. heat disapation. For example, If I use something like a voltage regulator, will I need to attach it to the metal frame with a heatsink and thermal paste/

    Thanks again for your help,
  4. Hello Laccchie
  5. Hi!!!!!! :woot: Your 'Mood' is definitely being shown. LOL
  6. Switch mode power supply DC/DC convertor would be the most efficient I guess, You need to look at the total load of globes, horn, and spark system. Maybe worth measuring the current to see what it draws when running. Yes you will probably need to mount it to metal so it can dissipate the heat. Something like THIS perhaps, that is 60Watts you may need more. The power figure you are drawing will dictate the size of convertor and also how long you get out of a battery before you are pushing home.
  7. Uncle Greg's the Master of subtlety, ;) he is trying to say you should go and do an introduction thread in the Welcome lounge. It is the custom around here.
    • Agree Agree x 2
    • Like Like x 1
  8. Not sure if I'm correct, but I don't think their will be any load besides lights, as the spark plug is generated by the coil, because the bike (engine) can run fine without the battery. Just that when I have the high beam, blinkers and brakes all on at the same time, all the lights dim, which would not be good on the road. Or if I ever register it. Correct me if I'm wrong.

    Would I measure the current via the battery leads in series?
  9. Ok will do, after I reply to the amazing amount of replies I'm getting :)
  10. Yes I can agree that it would be easier to just get a replacement battery, however this bike will not be run very often, maybe once every 1-2 months. So the battery will deplete and I will have to get a new battery, or buy a charger, which are $60-80 for a good one and I don't want to spend over $100 fixing this problem and I am an apprentice light vehicle motor mechanic and this will be a good thing to work on and learn a new aspect.

    It may seem like I'm throwing common sense out the window, but I like being different. :LOL:
  11. 1. wire 4 AA's in series.
    2.Wire a whole bunch of these in parallel.
    3. Ride.
    • Like Like x 1
    • Funny Funny x 1
  12. Yes measure the current in series with the battery lead.

    The ignition circuit does require power but the alternator/generator can provide that part of the circuit. You know I am sure, in a standard Kettering ignition the power charges the primary of the ignition coil and then when the points open the collapsing magnetic field provides the high voltage on the secondary of the coil and then to the spark plug.
  13. Could work, but would take up quite a lot of room, might as well remove the fuel tank. :)
  14. are you riding at night?
    if not don't bother with the battery
  15. Ok I will that then, I will have to wait until I get up to my friends place to be able to measure it, so I will reply with result when I do. Yes you are right, so what you are saying is that the battery powers the primary coil, then that coil provides power to the second coil through the points?
    • Like Like x 1
  16. I have only rode it in the dark twice, but once I restore it and bring it down to my place I will most likely register it. Also the battery also helps with the blinkers, which at the moment are quite dull. Same goes for the brakes. Also the horn it quite soft, so I will need the battery.
  17. my horn is never soft
    • Funny Funny x 1
  18. With mine, I can only sort of hear it over idle, but when I am at higher RPMS, it is not very loud.

    For example, I was trying to ride it from the patio to the backyard and a few dogs and chickens were in the way and I was 'blasting' my horn and they didn't even look at me. Revving the engine is the best horn I have.
  19. horns don't save lives

    some times they make them though
    • Funny Funny x 2