Rectifier regulator in parallel

Discussion in 'The Projects Forum' started by Samir246, Dec 7, 2015.

  1. Samir246

    Thread Starter New Member

    Dec 6, 2015
    4
    1
    Hi guys.
    I am currently working on my homemade v twin engine build. I have almost finished the mechanical bits and will be moving on to electrical part soon. I have absolutely no electrical background, so please pardon my lack of knowledge.
    I have a 200 watt alternator mounted on the engine shaft, which supplies three phase power to a rectifier regulator assembly. This assembly then supplies 12 volt power to a battery , ECU and other auxiliaries . My questions are
    1) Can I use one alternator to provide supply to two rectifier regulator assemblies that are connected in parallel? These two rectifier regulator assemblies will then supply power to two batteries , two ECUs respectively.
    2)if this can be done, then will it affect the functioning of the ECUs? Will the same 12 volts be maintained across them?
    3) will both batteries maintain their charge?

    FYI the total electrical load will not exceed 145 watts.. Alternator capacity is 200watts at 5000 rpm. Battery is 14 ampere hour. Fuses are of 20 amps.

    Looking fwd to hearing from you and once again sorry for my lack of knowledge
    Cheers
     
    RRITESH KAKKAR likes this.
  2. Sensacell

    Well-Known Member

    Jun 19, 2012
    1,132
    267
    Not enough detail to provide a meaningful answer.

    What type of alternator? Permanent magnet?
    What kind of voltage regulator is being employed?
     
  3. wayneh

    Expert

    Sep 9, 2010
    12,148
    3,058
    Assuming this is a permanent magnet alternator, in theory this can be done but I would question why. I'd rather have one robust system than two.
    Done properly, each regulator should function independently. But behavior under serious load could be unpredictable as one side impacts the other.
    You've only got so much power to deal with, so there will be times when the battery is not being recharged as quickly as otherwise possible. A big load on the engine could also cause poor running when you first start up. A friend's Harley would struggle against his headlight when he would start it cold. He did an LED retrofit and solved that problem. A fresh battery might have helped as well.
     
  4. Samir246

    Thread Starter New Member

    Dec 6, 2015
    4
    1
    Thanks for the info... The alternator is a permanent magnet type, however i do not know what type of rectifier regulator. I have attached a wiring diagram for the whole wiring harness. It is the one from a royal enfield bullet. The reason I'm using this particular harness is because the whole project is built around royal enfield parts.. I have already discussed my basic idea in my previous post. Basically I'm using one harness for the fed cylinder and an identical one for the aft one. The two harnesses will be connected just before the two rectifier regulator assemblies with a common alternator supplying power to both. Can u guys any potential problems or mistakes with this concept of mine.... Or a better way to achieve the goal. Thanks


    http://www.midlandbullets.co.uk/images/EFI workshop chart.png
     
  5. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    As I understand your problem, you have two engines, two alternators and two batteries, two ECUs, but some things, like lights and brakes, and other common accessories should be powered (automatically) from either battery.

    This is not unlike what happens in twin engine aircraft, where each engine is more or less independent of the other, but the two battery charging systems are combined so that either can power the common loads, like lighting, avionics, navigation, flight instruments, etc...

    You could expect that @ cruise RPM, two independent charging systems would maintain their respective battery voltages within a few mV of each other.
    I think that the question you should be asking is how to combine the outputs of two batteries, so that the common loads can take their power from either battery automatically.

    Will have some suggestions for you if you can better define your problem. As with most newbies, you jumped right to a proposed solution without really understanding what you need to do...
     
  6. tcmtech

    Well-Known Member

    Nov 4, 2013
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    1,667
    I see no logic in making it have two separate electrical systems to run what is essentially one engine with one alternator.

    All I see is more work being done and more parts being used to make something more complicated and thus likely less reliable than needed.
     
  7. Samir246

    Thread Starter New Member

    Dec 6, 2015
    4
    1
    Guys. I guess I have not been able to convey my thought on this project in a clear manner. I'll give it one more try...
    First of all, why use two diffrent electrical systems and complicate things? Well I have to use two diffrent ECUs as it controls a lot of factors like ignition timing, fuel injection etc. I want to keep all the combustion parameters same to meet with the local emission norms. Also one ECU is programmed for just cylinder. Hence I have to use two ECUs and all the other bells and whistles that come along with it.
    Secondly, I can use only one alternator, as it is mounted on the crankshaft and there is only one mounting point. Hence I had asked earlier if it was possible to supply two rectifier regulators with one power source. Also I would like to add that one harness would supply the forward cylinder and the various lights, while the second one supply just the aft cylinder.
    Appriciate all your support.. Cheers
     
  8. Samir246

    Thread Starter New Member

    Dec 6, 2015
    4
    1
  9. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    If there is only one alternator, then use only one regulator, and one battery. There is no reason why one battery cannot feed two different ECUs...
     
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