I’ve never used flexible filament. It would be fun to design a custom grommet. I’ll let you have that fun. Thanks for the compliment.
This is how I mounted my voltage alarms for now using balance lead extensions:
I’m not impressed with their accuracy but they are better than nothing for now. Eventually I will have a monitor on the gooseneck bar to display the voltage of the lowest cell.
The balance leads from the batteries plug into mounts like these:
Plugging the leads in like this also keeps them out of the props without fussing with other tie down methods.
Not sure if PM worked, Any chance you’ll be out this weekend?
I like your line of thinking. What will it take to get a display running that shows voltage of the lowest cell? That sounds like the perfect solution. Have you had one of these go off mid flight yet? Also what are the red components where the wires come out of each esc?
There’s a lot to figure out to be able to accurately monitor voltage of that many cells all at once on the same processor and to design a PCB for it. In the meantime Zach and Paul are working on something similar for batch 4. So we are debating if we want to finish our ideas or wait and see what they come up with.
The alarms I am using are often inaccurate on at least one cell so they almost always sound right before I land. They don’t go off mid flight though but I keep an eye on my total voltage and adjust throttle as needed as to not drop below 42v. Mid winter I damaged a couple cells mid flight and didn’t have these at the time. The resistance of the cells are higher when it’s cold so the voltage sag was greater which led to damage that could have been prevented with a good monitoring system. I also learned not to fly with cold batteries.
I think we are pushing the limit of wire length between the batteries and ESCs. Remember that long wires cause voltage spikes because of induction and that’s the reason why ESCs have capacitors in them. But those capacitors aren’t enough to support extra long wires. I’ve tried to keep my wires as short as possible including the leads of the batteries (this also keeps them out of the props). After I added added wire to connect two more batteries (total of 6) I had an ESC go bad on my first flight with that setup. I think the extra wire pushed it over the edge in combination of one year worth of previous wear from voltage spikes.
I replaced the bad ESC and added two more capacitors in parallel as close as possible to each ESC. The capacitors are identical to the ones inside the ESC. I covered the solder connection with liquid electrical tape and then used some 3D printed parts to secure them.
Here is a link to the capacitors:
I saw the following… This guy combined a few BMS to get all cell voltages! Expensive and still not enough space on the display…
Looking forward for a solution from Pdwhite or you…
I think the same and commented about this in the forum. If you use more than 4 Lipo’s, the wire
length is just too long. I bought these 63 v 5000uF (5x1000uF) Capacitors and will solder them to my ESC’s just to be on the safe side.
Keep up the good work!
I don’t want to display all cells. I only want to know the lowest cell and maybe a graph of all cells as a baseline for comparison.
On the picture with skies where you tested voltage alarms -
As you could not hear it would it be good if the throttlecontroller would vibrate shortly while the beep? My remote of the drone does so i like it.
Those alarms are a separate off the shelf item that have no way of being connected to the system controller. A custom monitoring system could feed a signal to the controller and make it vibrate. My plan is to have a display on the gooseneck bar that will flash to get your attention.
Is the low voltage alarm on your drone a separate system that could be purchased and adapted to OpenPPG or is it part of your drone?
No its part of the prebuild drone:
I hope that maybe in batch 4 that i have just ordered yesterday they could integrate it to the new alarmsystem…
Here you can see and hear some alarms
That concept is really good but it doesn’t help us that it’s integrated into your drone and can’t be purchased separately. Did you order the BMS with your batch 4? That will communicate individual cell voltage to your controller.
Just to be clear… OpenPPG shows system voltage on the controller. The thing it has been lacking is individual cell voltage which will be part of the batch 4 BMS. I added the alarms for now to let me know if I have a low cell.
Yes i did order the baterymanagement too.
I just thought when the droneguys can build such a system someone here could do it too…
I did read your comments about waiting for batch 4 or trying something right now on your own…
And you are right the lowest cell is the most important…
Why 5000uF vs Paul’s matching 330uF?
I soldered a 1/4”-20 brass bolt to an Xt 150 connector. I ran a tap into the connector first because the bolt was slightly too big. After soldering I cut it to the right length. Now the wires bolt directly to the connector with brass nuts (zinc plated nuts shown in the picture but I used brass). Now the connector cover is part of the surface mount holder.
Here are the files:
Xt 150 Mount Black - Face.stl (197.9 KB)
Xt 150 Mount Black - Middle.stl (141.5 KB)
Xt 150 Mount Black - Base.stl (304.1 KB)
Xt 150 Mount Black - Two Wire Cover.stl (293.2 KB)
Xt 150 Mount Black - Three Wire Cover.stl (316.2 KB)
This is the thread with all the links to read>
2 x 330uF Capacitors = 660uF / 220uF for every 4 inch extension of battery cable!
I searched for 7 x 63V 330uF capacitor packs (2310uF) and they are not available, but the
63V 5000uF packs were available and so I bought them. Are they overkill - maybe, but I am on the
When I build my batch4 I will use 100A ESC’s and thinking about putting the ESC’s inside with
I want to order a few parts at 3d hubs from your designs…
Is this material/infill/layer height correct?
Thank you for your time…