Page 21 of 22 FirstFirst ... 1119202122 LastLast
Results 201 to 210 of 217

Thread: Alternator delete with regen braking modification for better MPG

  1. #201
    Has anyone looked into an electric motor assist? I saw an old gm car with an LS? engine swap and a big electric motor mounted like an alternator with a wide cogged supercharger like belt going to the crank pulley. It also was a heavy car with a ton of batteries.

    I wonder if something similar but smaller scale would be worth looking into? Mount a small electric motor and have it assist the crank at cruising speeds? Might work good for putzing around town at 30-40 mph where once you're up to speed it doesn't take much power to keep moving.

    Found a link
    https://www.youtube.com/watch?v=4-Vck6oCi3A


    Mirage videos:

        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage SE wussie cvt edition. 1.2 automatic: 37.7 mpg (US) ... 16.0 km/L ... 6.2 L/100 km ... 45.3 mpg (Imp)


  2. #202
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,999
    Thanks
    2,892
    Thanked 1,804 Times in 1,017 Posts
    Quote Originally Posted by ProDigit View Post
    I'm late in the game. But it appears to me, you could just swap the battery out with a Capacitor pack, or a 4 cell Lithium battery? (like those motorcycle LEGO battery packs)?
    It's lighter, it's smaller, and it doesn't need as much charging.
    It also keeps (full) charge longer.
    A capacitor pack not as much, they might deplete overnight, but usually charge within like a few seconds.
    Which reminds me, I bought a USB battery pack (one of those 11000mAh battery packs) and it had a built in car starter (400CCA, up to 4L engines it said). It's not meant to start a car by itself, but to aid with the battery that's already present in the car.
    But use that on a 3 cylinder, 1,2L engine, and you probably don't even need a car battery.
    I tried starting my 800CC motorcycle with it, after the battery was totally dead, and it worked!

    So what stops anyone from just installing 2x $35 5F (rated, in reality they're 1F or 2F) capacitors, those huge water bottle size caps, and pair it with a USB battery pack for starting? That's not even 5LBS on starting gear vs 40?


    Excellent question Prodigit! You can certainly replace your starting battery with something smaller and lighter. Loren did that with his very small lead acid battery that he used to reduce weight for his autocross Mirage. However, that doesn't stop the alternator from putting a load on the engine. Just because you have a smaller battery doesn't mean your alternator has to work any easier. When you're driving around and you turn your headlights on, your alternator now has to generate 110W (2x 55W) more power to supply the power necessary for those headlights. That means your engine has to burn ~220W more fuel because alternators are at most 50% efficient.

    This modification completely removes all load from the alternator (except the belt, alternator fan and bearings) by telling the alternator that the battery is already full. Having a capacitor bank will not do that. Even having a lithium pack won't do that unless the new battery runs at a voltage above 14.4V. Because, as soon as the battery's voltage falls below 14.4V, the alternator starts pumping out power to maintain 14.4V. This is done by the voltage regulator that is inside the alternator.
    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  3. The Following User Says Thank You to Daox For This Useful Post:

    LetItMarinate (04-24-2020)

  4. #203
    Still Plays With Cars Loren's Avatar
    Join Date
    May 2018
    Location
    Florida
    Country
    United States
    Posts
    1,225
    Thanks
    324
    Thanked 936 Times in 539 Posts
    I just spent probably 90 minutes reading through this thread again.

    How 'bout a quick update?
    Simplify and add lightness.

  5. The Following User Says Thank You to Loren For This Useful Post:

    TcoloT (08-12-2023)

  6. #204
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,999
    Thanks
    2,892
    Thanked 1,804 Times in 1,017 Posts
    There really isn't too much to update. The mod works great. I haven't had any other issues with it.

    I had to disable it when I made a long trip to help out a friend who had his car break down about 2 hours away. The battery just wouldn't have lasted the full trip so I just disabled it. With this in mind, I would like to set it up so it won't overcharge the battery when the alternator is turned on. However, the priority of doing this is so low it'll probably never happen. Reenabling the alternator is as simple as popping the hood and replacing the normal fuse vs my mod fuse jumper.
    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  7. The Following User Says Thank You to Daox For This Useful Post:

    Loren (10-12-2020)

  8. #205
    Still Plays With Cars Loren's Avatar
    Join Date
    May 2018
    Location
    Florida
    Country
    United States
    Posts
    1,225
    Thanks
    324
    Thanked 936 Times in 539 Posts
    I was thinking about maybe setting it up with a circuit to monitor battery voltage and automatically enable the alternator when voltage reaches a certain threshold. Sort of a fail-safe. Battery gets down to 11.7 or whatever, kick on the alternator to save the battery. Maybe keep it enabled until it reaches 12.2 or something.

    I can't remember, are you just doing a full alternator disable right now? Plug-in charging as-needed? Or did you implement an brake-enable system?

    I was thinking of doing something similar, but with a solar charger so I don't have to plug the car in. Add in the low-voltage fail-safe, and it would be a fully automated system.
    Simplify and add lightness.

  9. #206
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,999
    Thanks
    2,892
    Thanked 1,804 Times in 1,017 Posts
    My current setup has a switch to turn the alternator on and off. I haven't tied it into the brake pedal or anything yet though.
    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  10. The Following User Says Thank You to Daox For This Useful Post:

    Loren (10-12-2020)

  11. #207
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,999
    Thanks
    2,892
    Thanked 1,804 Times in 1,017 Posts
    I have a quick update on this mod. I need to update my circuit so it stops charging at 15V. This fall I noticed decreased cranking power now that its been colder out. I investigated and noticed the water level in the battery was low. I think I put in just over 1 quart of water into it to top the battery off! Apparently 15V at 90A charging causes some water loss haha. The stock operation of the voltage regulator is to charge at a max of about 14.5V and once the battery is closer to full it drops down to 14V. Doing this shouldn't reduce the usefulness of the regenerative braking too much. It just won't charge it quite as aggressively when its more fully charged.
    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  12. #208

    Me too me too!

    A buddy of mine gave me a giant 12v battery from a boat that he sold last summer. (Well, I bought him some beer as a thank-you.)

    So with the warmer weather here and the added capacity, I think I'm going to try some alternator-optional motoring.

    I tried it a couple of days ago simply by disconnecting the 4-wire plug to the alternator. Charging stopped, but interestingly the dashboard battery light did not come on. (EDIT: it didn't come on because one of the signal wires in the 4-wire plug -- the "L" wire -- tells the ECU to light the dashboard battery light. If it's disconnected, it can't receive the signal.)

    Anyway, I think I'm going to try a simple switch instead of a fancy automated setup.

        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage ES 1.2 manual: 63.2 mpg (US) ... 26.9 km/L ... 3.7 L/100 km ... 75.9 mpg (Imp)


  13. The Following User Says Thank You to MetroMPG For This Useful Post:

    mohammad (07-17-2022)

  14. #209
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,999
    Thanks
    2,892
    Thanked 1,804 Times in 1,017 Posts
    Very cool! I look forward to seeing what you come up with.

    A simple switch won't work because the voltage regulator cranks the output to 15V if it doesn't get any signal.
    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  15. The Following User Says Thank You to Daox For This Useful Post:

    MetroMPG (04-27-2021)

  16. #210

    Not one switch...

    OKAY, so maybe not ONE switch.

    But it looks like you might never have tested for alternator output with more than 1 wire disconnected.

    I can confirm that with the whole 4-wire plug disconnected, charging DOES stop (and does not resume above 2k RPM).

    - First you first disconnected the FR (field regulator) wire ... and that didn't work. The alternator self-excited above 2k RPM and switched on again (probably some kind of failsafe mode to continue charging).

    - Then you disconnected the S (battery voltage sensing) wire ... and that didn't work. The alternator defaulted to blasting out 15+ volts. Yet another failsafe mode.

    - Then you went with the DC-DC converter approach to spoof the voltage on the S wire and trick the alternator into shutting off.

    So perhaps it's possible to accomplish this by switching off those two wires simultaneously. (Or maybe it needs to be all 4. Who knows?)

    Or I could just spend the ~$10 and order a DC-DC converter, voltage regulator and capacitors (those last 2 items you discovered you needed after cooking a DC-DC) and copy your approach!


        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage ES 1.2 manual: 63.2 mpg (US) ... 26.9 km/L ... 3.7 L/100 km ... 75.9 mpg (Imp)


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •