Reviving this thread just to share data on one more battery. This thread was enlightening indeed and explained (to me) why recent users of 9V launch controllers were having issues. It also clearly showed that my standard recommendation of Duracells is now no longer valid. It also points to options that won't be as pricey as lithium 9Vs that should work fine in the upcoming Aerotech Phaser launch controller (shown here:
#6,918 ) as well as in the older Quest 9V controller, the little orange Estes Astron II controller and in the old Estes Star Wars R2D2 controller.
As I mentioned in post 46, I like to test things, and this led me to try and figure out how I might do some testing along these lines. My favorite test equipment from my electric RC airplane power systems days require Windows 7 (Medusa Research now out of business, no newer drivers/applications) and so aren't as usable as they once were. But I do have one piece of test equipment that can do amps, volts (and a bunch of other electric power system parameters) simultaneously and which doesn't require a computer to be used. This is the Hyperion Emeter II. I figured out a way to test 9V batteries using the Emeter II, a couple of clip leads from my 3-pad launch system, an old Estes 9V controller (in the shape of R2D2) and plenty of Estes Solar Starters (the ones we all love to hate). The Emeter II is limited to 8 samples/second and since it's more intended for testing electric power systems, the current resolution is 0.1A, but it let me do one interesting test and I'll likely do more.
Then, not wanting to buy a pack of eight Amazon Basics 9Vs to play with I went looking at others that were marked "6LR61". That (and a claimed 7-year shelf life) led me to a brand called Voniko (specifically
these) which were 4 for $7.
When I got them I used my DVM to do a couple of short-circuit tests as described by
@QFactor in the first post - though I just read the current and then the voltage afterward (and failed to write the values down). The currents were in 4.5A range initially, I think. Then I put the same battery in the R2D2 launch controller, replacing the fresh Duracell that was in there, but which wold
just barely fire an Estes Solar Starter. The Voniko fired the starter quickly and with much enthusiasm. After doing several of these the current dropped off a bit and the resting voltage of the battery was right at 9V. I puzzled awhile about how I was actually going to hook up the Emeter's micro data unit (which has Anderson Power Poles on its leads) in the circuit. Then I remembered that my 3-pad personal system is all wired with Powerpole connections, including for the clip leads. So I have several sets of wires with micro clips on one end and Powerpoles on the other. I used one of these on the output end of the MDU and clipped the igniter clips from the R2D2 controller to the input lead. This let me get a good set of data for the current but the voltage didn't make sense (I think now I had a polarity issue as the Emeter doesn't read negative voltages).
But what I really wanted was the MDU between the battery and the controller. This required using two of my Powerpole clip leads. One pair of micro clips would then connect the battery to the input side of the MDU and the other pair, on the load side of the MDU, would connect to the battery connector in R2D2. The igniter then was then connected to the R2D2 controller using it's own clips. Using this setup, and the same battery I'd been testing (which was reading just over 9V at rest, compared to 9.69V for the other three from the 4-pack), and getting polarities sorted so that the Emeter was seeing the battery voltage and the LED continuity indicator in R2D2 was working, led me to a data set that I thought was worth sharing.
The Emeter II data is recorded to a log file which is essentially a .csv format, so I put the data into MagicPlot, fussed around and finally got something worth showing.
The test sequence was this: connect everything up with the key out of the controller. Wait ~5s then put the key in. Give a mental countdown from 5 and push the launch button, holding until the igniter burned out. Then wait a few seconds, pull the key (no continuity at this point). Then stop the recording, pull the SD card, come back to this computer and fuss with MagicPlot for too long.
Now, after all these words, we have this:
View attachment 611862
As I mentioned the Emeter II's current sensing resolution is 1/10th A, so you can't see arming the controller at all since continuity is shown by a little red LED. And apparently that LED's draw doesn't pull the voltage down enough to show in the data either.
Bear in mind that when this was done the battery had probably had a dozen shorts or igniter firings already on it. AND — there are three sets of flat-jawed micro clips and a total of about 18 feet of small gage wiring (similar to today's Electron Beams) in the circuit. The igniter fired with sufficient vigor I'm sure it would have done its job and lit an Estes motor. The length of the current spike, from pushing the button until the igniter burned out is 1.375s (remember 0.125s sample interval).
I need to do this again while videoing in slow motion to show the igniter firing.
After I've abused this particular battery enough, I'll disassemble it and put up pictures. But I expect, it being marked 6LR61, I know what I'll find.
And then, of course, I could refine my test setup and do several different batteries and maybe also do capacity tests on them. I have a little tester gadget in my Amazon cart that would make such things fairly straightforward. I should also take pictures of the test setup and share those.
More to come, if folks are interested....