Announcement

Collapse
No announcement yet.

Branch's SSG Build

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #76
    Originally posted by Branch Gordon View Post
    I looked up the lawn & garden batteries I am using that I got from True Value. Looks like they are rated at 20AH.

    Interstate SP-35 Lawn & Garden Battery 300 CCA

    That still gonna be ok?
    yes that is fine. its also good to see how resistance changes can produce a rise in rpm, that you can see the bell curve form on both sides if the resonant point.

    Tom C


    experimental Kits, chargers and solar trackers

    Comment


    • #77
      Excellent, thanks Tom. I've ordered some 110 ohm 1W resistors, so I can switch over to using a fixed resistor. Not that I have a tuning point, good batteries, and my baselines charted...I can confidently begin my test runs.

      Originally posted by Tom C View Post
      yes that is fine. its also good to see how resistance changes can produce a rise in rpm, that you can see the bell curve form on both sides if the resonant point.

      Tom C

      Comment


      • #78
        Ok I'll be working through test runs for the next 6 weeks I'm guessing. I'll post my results every 5 runs with comparisons against the original baseline.

        Comment


        • #79
          Finished my first run and the charging time wasn't ideal. I realized that when I created my RPM's vs Resistance chart, I didn't factor in amp draw at all.

          I ran through all the resistances again last night, and found two points which I believe are sweet spots. Here is what I found:

          Sweet Spot 1

          318.2 RPMS - 740mA - 51.2 ohms
          317.4 RPMS - 750mA - 48.1 ohms
          316.7 RPMS - 760mA - 46.1 ohms
          316.7 RPMS - 760mA - 44.3 ohms
          316.2 RPMS - 760mA - 42.1 ohms
          315.8 RPMS - 780mA - 34.2 ohms
          346.6 RPMS - 590mA - 32.4 ohms

          Sweet Spot 2

          291.0 RPMS - 380mA - 160 ohms
          290.8 RPMS - 370mA - 163 ohms
          288.8 RPMS - 360mA - 165 ohms
          272.3 RPMS - 430mA - 167 ohms
          271.5 RPMS - 430mA - 171 ohms

          With the first sweet spot...if I move up to 34 ohms, the amp draw stays around 760mA, and doesn't shift down. At 32.4 ohms, the wheel speeds up to around 317 RPMS, hangs for a minute at 780mA, and then shifts down to 590mA and the wheel speeds up to 346 RPM's.

          Does this sound like I've found the correct sweet spot?

          I believe the amp meter and extra cable to hook it up in series is adding some resistance, so when it's removed...the sweet spot will shift. Should I just compensate by moving up slowly in ohms without the amp meter until I find the shift again?
          Last edited by Branch Gordon; 05-17-2013, 08:17 AM.

          Comment


          • #80
            Branch, sweet spot number one is the way to go. Now remove the ammeter and put in a fixed resistor that will give you the 346 rpm you're looking for.

            John K.

            Comment


            • #81
              Thanks John. I am glad I'm on the right track.

              When I ran the tests above to determine those sweet spots, the primary voltage was sitting at around 12.2V. However, after charging the primary...the RPM's are different at a higher voltage, as is the "shifting" point. It seems to be at around 50 ohms with a full charged primary battery.

              Is this normal? Which spot is best? Is the sweet spot supposed to shift as primary voltage changes?

              Comment


              • #82
                John-

                Never mind...I looked through some older threads and see that you've told people before to tune the machine with a full primary battery.

                Sticking with 50 ohms.
                Last edited by Branch Gordon; 05-19-2013, 04:35 PM.

                Comment


                • #83
                  Heya. I think you may have posted in the wrong thread. I don't have a lab...and my SG runs great.

                  Cheers!

                  Branch

                  Originally posted by Thunderlance
                  Sorry for your loss Mr. Bedin, I hope your lab. was insured and nobody was hurt. If your SSG don't start up as it should maybe you are not spinning the shaft fast enough manually . I've come to find out that is what I over looked for a few months.

                  Comment


                  • #84
                    There should be an option right below your post to "edit". Then you click delete.

                    I'm sure someone out there is charging car batteries...maybe create a thread on it and see who bites?

                    Comment


                    • #85
                      Getting ready for my 4th charge/discharge cycle. The past two curves have displayed gradual improvements, so all is looking good so far. The last discharge cycle I got about 2 1/2 amp hours more than where I started.

                      I'll post a screenshot of the curves once I get to 5 so everyone can see the improvement.

                      Branch

                      Comment


                      • #86
                        So it's currently taking me 5 charges of the primary to get the charging battery up to 15.x volts. As in...I run the primary down to 12V, stop the SG, recharge the primary, start the SG again, and continue charging. Does that sound normal for the first cycles?

                        Just to confirm...the expected result after a number of cycles is that it will only take 1 charge of the primary to charge the charging battery...correct?

                        Branch

                        Comment


                        • #87
                          Branch, you could take just 1 or 2 amp hours out of the charge battery initially when you load it.
                          I would start off with taking just 1Ah out of it, while you're doing this re-charge the primary. Then next time charge the secondary to 15.3v. Note the voltage of the primary when you're done. If the primary is at 12.3v for example, take 2Ah out of the secondary next time. Keep doing this an increasing the amount you take out of the charge battery each time.

                          Ideally you want to charge the secondary without having to recharge the primary in between. New batteries take a few cycles to properly form the plates as they aren't formed properly in the factory anymore.

                          John K.

                          Comment


                          • #88
                            Hey John-

                            I'm not sure I follow...

                            What I've done the last three complete runs is that I don't load the charging battery at all until it's fully charged. So the charging battery is just sitting...resting...until my primary fills back up, and then I continue to charge to 15.3v.

                            As they are 20AH batteries, I've been using a 1 amp load with the CBAIII for the discharge.

                            So...to confirm..you are saying I shouldn't let the charging battery rest...that I should discharge it a bit...before continuing it's journey to 15.3v?

                            If it's still taking 5 recharges of the primary after 10 or so complete cycles of the charging battery....would you think I have a tuning issue?

                            Thanks,

                            Branch

                            Originally posted by John_Koorn View Post
                            Branch, you could take just 1 or 2 amp hours out of the charge battery initially when you load it.
                            I would start off with taking just 1Ah out of it, while you're doing this re-charge the primary. Then next time charge the secondary to 15.3v. Note the voltage of the primary when you're done. If the primary is at 12.3v for example, take 2Ah out of the secondary next time. Keep doing this an increasing the amount you take out of the charge battery each time.

                            Ideally you want to charge the secondary without having to recharge the primary in between. New batteries take a few cycles to properly form the plates as they aren't formed properly in the factory anymore.

                            John K.
                            Last edited by Branch Gordon; 05-27-2013, 05:48 PM.

                            Comment


                            • #89
                              John,

                              Here's an example of my last charging cycle.

                              Click image for larger version

Name:	runs.jpg
Views:	1
Size:	63.6 KB
ID:	45607

                              You can see I started at 12.34v....ran the primary all the way down...and the charge term voltage ended at 12.85v.
                              So I had to recharge the primary, and go again, and again. The last run I finally hit 15.00v.

                              After this I ran a discharge curve on the charging battery.

                              Comment


                              • #90
                                Branch, what I'm suggesting is that once you have your charge battery charged up to 15.3v just take 1 amp out of it for 1 hour (1Ah). During the load time recharge your primary with a normal charger, such as a 2A12.
                                Then recharge your secondary back to 15.3v.
                                The idea is that you only load the secondary down so the primary can last long enough to charge it back up to 15.3v in one go on the next cycle.
                                If you find that you still have juice left in the primary after charging the secondary up to 15.3v, you can take a little more out of the secondary next time.

                                John K.

                                Comment

                                Working...
                                X