Have you considered using 8 batteries for a longer flight?
Approx 45lbs additional weight - I personal would want a trike to carry that
For a longer flight: Climb, climb. climb, float, float. float.
45 minutes float from 17,200 ft calculates to 382 ft/min.
Climb to 5,000 ft and gain 13 more minutes in the air.
How high can your EPPG climb to on a charge?
I dont think fun flying for me is flying high – I got attracted to this type of flying from the vids of folks flying lower.
Had my first flight this weekend! (had to wait to get my reserve to fly) Batch 2 w/ 4 Bonka batteries, Ozone Spyder wing, Dudek Powerseat low hang harness w/ reserve. My weight 185 lbs. Wind at 5-8 mph on ground with some midday thermals.
Flew for about 18-20 min. Forward takeoff was short and quick. Climb to about 800 ft. (about 75% throttle) with a couple of descents and climbs in between before landing. Cruse for a bout 7-10 min at 40-50% power. When I landed, battery capacity was at 15-20%. Plenty of power without having to go full throttle.
Some thoughts: Batteries were warm but not out of the ordinary, Will be adding a pre-charge button to help with main battery disconnect switch activation, will be looking into a way to secure the leg hinges to lock into place to make the unit more stable on the ground during setup and hoop install.
Overall, very exciting to get into the air. I have been paragliding for 10 years and really enjoyed using a motor to launch and get a quick flight in without having to go to the top of a mountain. Would of had video but my chase cam malfunctioned!
Try these @Mhilll. They work really good and don’t require any extra setup steps.
You could run 6 bonkas to get 66ah @ 15kg (35lbs?). I think 8 would be a lot of extra weight.
Thanks @GliderPilot for the response. I actually have the hinge stop plates installed on my frame. They really help to stop the hinge at the right angle and help to keep the motor standing upright and align the hoop. I might try to print a stop plate with a hinge barrel/loop on each peice that a locking pin can be inserted to lock the hinge in the open position. Might add some rigidity to the frame at the hinge point. Also, the thought being that you can fold the arms in while the motor is standing and not have the motor legs fold down from the weight. Then once you are ready to fold the legs up, just remove the pin. Might be overkill but thought I might give it a try and see how it works.
I should probably post a video of how I set mine up and take it down. Basically, I store it and carry it with the harness on the bottom and the legs on top. My first step is to open the legs and bottom arms and install the bottom hoop pieces. Then the legs don’t move at all when I stand it up. It works pretty smooth.
@Mhilll, here is a video of my setup. You can see how well the hinge stops work as well as my arm latches that click lock when the arms are opened. Also, make sure to tighten the bolts on the leg hinges because they are designed to use friction to add a little resistance. Not so much that they don’t move freely though.
I flew yesterday with two Bonka 2200 mah batteries. I launched easily and quickly with my Axis Pluto wing. I am at the top of the placard weight range on it. I did several touch and goes, maybe three, and no higher than 200 feet. I was aloft for approx. 12 minutes and landed with 7% battery left. Before flying my Openppg I flew my gas powered motor unit. It’s powered by a HE 125 motor. It has normal thrust (125 lbs.), torque and vibration, but there was an amazing difference in lower noise, torque and vibration with the Openppg unit. If I get a more efficient wing and fly higher using thermals to maintain height, I should get around 15 minutes for two Bonkas.
@GliderPilot, Thanks for the video. Very helpful to see your process. I will make sure my hinges are tighter and see if that solves my issues.
Update on flight times. I flew again yesterday with only two Bonkas. Solid 15 minutes of flying. With a more efficient wing I may get a few more minutes, but my 9 year old wing doesn’t have the glide of newer wings. I only went to 360’ altitude. Landed with 0% battery power showing on the display, and 4.14 volts. Looking forward to getting two more Bonkas on board for 30 minute flights.
15 min on two bonkas is awesome! Were the batteries hot after the flight?
I’ve seen some people say that it’s dangerous to completely discharge the batteries… thoughts?
As I was descending from 350 ft., I had about 2-3% left, I used a bit of power ( maybe 30% ) to maneuver into my landing area. I checked after I landed and it showed 0%, 4.14 V. I think that should be within safe standards.
Does the system stop power if it gets to 0% or does it keep drawing power? I’m wondering if I build a li ion pack if I should install a bms to regulate the battery power or if the open ppg has something already that regulates voltage of packs?
I think Bill meant 41.4V.
When the controller reads 0% each cell is about 3.5V. That’s a safe level to discharge to. Going below 3.2V will ruin the battery.
The system doesn’t stop at low voltage nor would you want it to. I would rather have that power if you absolutely need it at the risk of ruining the battery than to have it shutdown on me unexpectedly. Anything unexpected like that would add a level of danger. It’s not hard to monitor your battery level and land accordingly.
Awesome thanks. This is how I expected it should work. Agreed nicer to have that reserve power just in case.
To answer your question, the batteries were warm after the flight but not hot.
One more thing regarding my 15 minute flight. I did one touch and go, went to 350 ft. and stayed there monitoring my battery life. I tried to manage power as frugally as possible to see how long I could stay aloft. When I added power the battery % might drop from 20% to 11% quickly, but it would return to a higher number ( maybe something like 17%) when I would back off the power.