I just stumbled across this video thank goodness because I just build a 4s2p 7000mah pack using the exact same sanyo 18650s, I've done these test but still not sure of this pack, at full throttle on takeoffs my ar wing pro pulls 26 to 28 amps after reaching altitude it can easily cruise pulling 5 to 7 amps. So whats your thoughts on this pack? Thanks for video. New subscriber
Truly informative video! I'm surprised your extremely clear how-to videos don't get more views. Note: 20:00 The plane converts POTENTIAL energy to forward motion at night.
One thing i am wondering. You mentioned that it is important to find out the max current of the craft. But is it not more important to find out the max watt output? Because you can play around with higher voltages to reduce the needed current. For example a 6s4p against 4s4p will result into 33% less required current. What would you recommend. Going for a 6s with less parallel or going for a 4s with more parallel?
Needing to know the amp draw assumes that you are converting an existing aircraft to Li-Ion. If you have a 4S setup, and run 6s, (assuming the ESC's and BEC, as well as any other devices that may be running from the main flight pack directly can handle the extra volts), you will overload the motors, and burn them up, if not re-propped. You will need to pay attention also to the motor's max Cell count in it's specs, as motors also have an rpm limit that cannot be exceeded without damaging their structures or components, such as magnets, or coils. If you are designing the system from scratch, go with the highest voltage that is practical, and you can find good components for. Lower KV motors to match, then adjust prop size to stay within the motor's specs. less current requires more voltage, so more cells in series. there is no advantage there for the battery weight, provided that the number of cells in parallel and series is designed properly, but there is a savings in wire size/weight, and the size/weight of the ESC's. Higher voltage is better in this regard.
Thanks for another great video Spike! Looking forward to experimenting with building this type of battery very soon. Your videos are the first ones I found were the person making them really looked like they knew what they are doing :-D
Something like that. It's not finalized yet. Good eye! If all works out, should have retractible gear, 17 inch props, slotted flaps for STOL, an airfoil that gives better cruise performance, be more modular, and all around better in every single way. It's not easy to make something better than V-2. span will be around 4 meters, but the largest part will be 1 meter in length.
FPVREVIEWS sounds promising! At some point I was considering to modify your original v2 plan and add a retractible landing gear, something like Canadair 415 or Catalina type for the main gear and a 90 rotation nose gear with the retracted wheel under the bat. Compartment horizontally. But than I decided to use the available weight for other equipment rather than a retractable landing gear. Anyway just an idea for your new version, this was reference for the main gear mraerodesign.securicom.ca/en/products/info.cfm?ProduitID=58 Look forward to see your new version!
To achieve a wider stance, and use more conventional 90 degree retracts, I believe it's far better to retract the main gear into the motor nacelles, similar to a Q400. Of course this requires a redesign, and it took some time to work out the overall aircraft geometry to get it to work out. also relying much more on composites to save weight, while actually making the aircraft even stronger, and more rigid. There is now an endo skeleton of carbon fiber, all the way from the core out to the extremities, with plug in joints, but retaining a minimized wood structure for aerodynamic fairing. To achieve this, it's necessary to use jigs extensively to make things line up, so planning on producing it as a finished model, rather than plans or kit. It's far more work to build the jigs, as it is to build the aircraft. Of course, designing everything in CAD as well. The cost of the retracts (good ones) is also significant, so that can be more easily absorbed by professional users, rather than hobbyists. The V-2 was originally intended for hobby use, however, ended up being used by professionals as well, for lack of a better option. so many (super expensive, 100 000 dollar+) UAV's cannot gently land a payload, and use parachute recovery. This is not practical for commercial use. It's great for the military, as they don't need to train the person very much to walk over and pick up the aircraft, as opposed to actually landing it, even in stabilized mode. Unfortunately, the aircraft is often damaged, and therefore is only used a few times before getting sent back to the company for repairs. It costs a fortune to repair, and transport. not a problem for the military, but if you are trying to map fields, and take atmospheric samples for local studies, it's prohibitively expensive. Those expensive aircraft often do not perform as well in the air as the V2 either. will keep the V-2 for kit and scratch builders. may redesign the wing at some point to be easier to build and save weight, but there is not a lot to be gained there. It's still a great airplane, and hard to beat. I still have to see whether the new aircraft will perform significantly better or not..
Thanks, we just finished a build video series for the Laser cut kit Gemini V-2, and are working on some upgrades for everyone for it too. Have not been flying lately, but hope to get back to making flying videos very soon. Cheers!
Spike, your videos are awesome! Thank you so much for making them. I just order 12 samsung 50e 21700 cells to build a 4s3p pack to go in a Phoenix 2400.
Thanks For sharing this useful information that covered quite few i had but i would like a indepth vídeo that could shed light on variuos options on designs and stimated amps, voltages, series and parallel Tesla style batterys if it's not posible to get your hands on brand 18650 because of their cost, maybe use some of the less then adequate chiniese brands assuming they may do the job. Greetings from TJ baja.
We have a couple of build videos showing the techniques used for assembling the batteries on this channel. If you want to use cheaper options, then better go over to Jehu Garcia's channel, just look up his name. He is the master of re purposing Li-Ion cells. he's also from TJ. saludos desde ENS BC, Somos casi vecinos!
No, it's just a hat My wife purchased for me. I consider them competition, although I have friends who work there, and admire many of their projects. in particular, the Sugar Volt concept.
I have found that a Multistar lipo beats the Li-Ion in every category, weight, capacity and longevity. I did an in depth study of both and it's far cheaper to get the Multistar batteries then it is to harvest a ton of Li-Ion cells from laptop batteries and what not. Another issue with Li-Ion is how much amperage they can put out, excellent cells can handle about 3A constant but "normal" cells, the ones you find almost everywhere, can do about 2.4A each which usually ends up meaning you have to build a massive pack in order to get the same discharge rate as a good Multistar lipo. :)
A well designed endurance aircraft should only require about .25C discharge rate for the overall flight. The cells are 3.5 amp hours, and can put out 10 amps continuous, so can be depleted in nearly 1/3 of an hour, which makes them about a 3C discharge. Plenty for the application that I'm using them for. If you watch the video, we explain how we go about calculating the minimum battery size. To beat the lithium Ion cells on the terms that you mention, the Multistar must have a gravimetric energy density greater than 224 wh per kg. according to the specs I looked up for the multistar battery, it only has a gravimetric E.D. of 175 wh per kg. Pretty typical for a low discharge rate lipo, Which it is. price per KG is not much different, but quality is likely to be inferior to the Sanyo cells. at 10C discharge rate, it may be better for some multi rotors, but not for most UAV aircraft. I'm not harvesting batteries from dead laptops. I'm purchasing the best cells that are commercially available from the most reputable companies.
All what you say is not true. a good 18650 battery is about 3500mah @ 20A. make a 4s10p from those and you have a 35000mah @ 80A at a weight of 40*40=1.6KG. thats more than enough to run a dual prop 11 inch for about 200 to 300km.
I just stumbled across this video thank goodness because I just build a 4s2p 7000mah pack using the exact same sanyo 18650s, I've done these test but still not sure of this pack, at full throttle on takeoffs my ar wing pro pulls 26 to 28 amps after reaching altitude it can easily cruise pulling 5 to 7 amps. So whats your thoughts on this pack? Thanks for video. New subscriber
Truly informative video! I'm surprised your extremely clear how-to videos don't get more views. Note: 20:00 The plane converts POTENTIAL energy to forward motion at night.
One thing i am wondering. You mentioned that it is important to find out the max current of the craft. But is it not more important to find out the max watt output?
Because you can play around with higher voltages to reduce the needed current.
For example a 6s4p against 4s4p will result into 33% less required current. What would you recommend. Going for a 6s with less parallel or going for a 4s with more parallel?
Needing to know the amp draw assumes that you are converting an existing aircraft to Li-Ion.
If you have a 4S setup, and run 6s, (assuming the ESC's and BEC, as well as any other devices that may be running from the main flight pack directly can handle the extra volts), you will overload the motors, and burn them up, if not re-propped. You will need to pay attention also to the motor's max Cell count in it's specs, as motors also have an rpm limit that cannot be exceeded without damaging their structures or components, such as magnets, or coils.
If you are designing the system from scratch, go with the highest voltage that is practical, and you can find good components for. Lower KV motors to match, then adjust prop size to stay within the motor's specs.
less current requires more voltage, so more cells in series. there is no advantage there for the battery weight, provided that the number of cells in parallel and series is designed properly, but there is a savings in wire size/weight, and the size/weight of the ESC's. Higher voltage is better in this regard.
Thanks for another great video Spike! Looking forward to experimenting with building this type of battery very soon. Your videos are the first ones I found were the person making them really looked like they knew what they are doing :-D
Gemini V-3 at the back? ;)
Something like that. It's not finalized yet. Good eye!
If all works out, should have retractible gear, 17 inch props, slotted flaps for STOL, an airfoil that gives better cruise performance, be more modular, and all around better in every single way. It's not easy to make something better than V-2. span will be around 4 meters, but the largest part will be 1 meter in length.
FPVREVIEWS sounds promising! At some point I was considering to modify your original v2 plan and add a retractible landing gear, something like Canadair 415 or Catalina type for the main gear and a 90 rotation nose gear with the retracted wheel under the bat. Compartment horizontally. But than I decided to use the available weight for other equipment rather than a retractable landing gear. Anyway just an idea for your new version, this was reference for the main gear mraerodesign.securicom.ca/en/products/info.cfm?ProduitID=58
Look forward to see your new version!
To achieve a wider stance, and use more conventional 90 degree retracts, I believe it's far better to retract the main gear into the motor nacelles, similar to a Q400. Of course this requires a redesign, and it took some time to work out the overall aircraft geometry to get it to work out.
also relying much more on composites to save weight, while actually making the aircraft even stronger, and more rigid. There is now an endo skeleton of carbon fiber, all the way from the core out to the extremities, with plug in joints, but retaining a minimized wood structure for aerodynamic fairing. To achieve this, it's necessary to use jigs extensively to make things line up, so planning on producing it as a finished model, rather than plans or kit. It's far more work to build the jigs, as it is to build the aircraft. Of course, designing everything in CAD as well.
The cost of the retracts (good ones) is also significant, so that can be more easily absorbed by professional users, rather than hobbyists.
The V-2 was originally intended for hobby use, however, ended up being used by professionals as well, for lack of a better option.
so many (super expensive, 100 000 dollar+) UAV's cannot gently land a payload, and use parachute recovery. This is not practical for commercial use. It's great for the military, as they don't need to train the person very much to walk over and pick up the aircraft, as opposed to actually landing it, even in stabilized mode. Unfortunately, the aircraft is often damaged, and therefore is only used a few times before getting sent back to the company for repairs. It costs a fortune to repair, and transport. not a problem for the military, but if you are trying to map fields, and take atmospheric samples for local studies, it's prohibitively expensive. Those expensive aircraft often do not perform as well in the air as the V2 either. will keep the V-2 for kit and scratch builders. may redesign the wing at some point to be easier to build and save weight, but there is not a lot to be gained there. It's still a great airplane, and hard to beat. I still have to see whether the new aircraft will perform significantly better or not..
AT WHAT VOLTAGE PER CELL YOU CAN TELL THAT YOU ALREADY CONSUME 80% CAPACITY OF A LI-ION BATTERY?
you should be able to get an idea on that from the data sheet in the description. It will vary with load, and temperature.
Hello Spike
Glad you are always at this
Haven’t seen much recent from you
Most nice to see you
Thanks, we just finished a build video series for the Laser cut kit Gemini V-2, and are working on some upgrades for everyone for it too. Have not been flying lately, but hope to get back to making flying videos very soon. Cheers!
Spike, your videos are awesome! Thank you so much for making them. I just order 12 samsung 50e 21700 cells to build a 4s3p pack to go in a Phoenix 2400.
Thanks For sharing this useful information that covered quite few i had but i would like a indepth vídeo that could shed light on variuos options on designs and stimated amps, voltages, series and parallel Tesla style batterys if it's not posible to get your hands on brand 18650 because of their cost, maybe use some of the less then adequate chiniese brands assuming they may do the job.
Greetings from TJ baja.
We have a couple of build videos showing the techniques used for assembling the batteries on this channel. If you want to use cheaper options, then better go over to Jehu Garcia's channel, just look up his name. He is the master of re purposing Li-Ion cells. he's also from TJ.
saludos desde ENS BC, Somos casi vecinos!
Dang! Excellent, excellent, excellent INTEGRATED (way too rare) explanation. Does your Boeing cap mean you're up in Everett?
No, it's just a hat My wife purchased for me.
I consider them competition, although I have friends who work there, and admire many of their projects. in particular, the Sugar Volt concept.
thank you all this useful information
I have found that a Multistar lipo beats the Li-Ion in every category, weight, capacity and longevity. I did an in depth study of both and it's far cheaper to get the Multistar batteries then it is to harvest a ton of Li-Ion cells from laptop batteries and what not. Another issue with Li-Ion is how much amperage they can put out, excellent cells can handle about 3A constant but "normal" cells, the ones you find almost everywhere, can do about 2.4A each which usually ends up meaning you have to build a massive pack in order to get the same discharge rate as a good Multistar lipo. :)
A well designed endurance aircraft should only require about .25C discharge rate for the overall flight. The cells are 3.5 amp hours, and can put out 10 amps continuous, so can be depleted in nearly 1/3 of an hour, which makes them about a 3C discharge. Plenty for the application that I'm using them for.
If you watch the video, we explain how we go about calculating the minimum battery size.
To beat the lithium Ion cells on the terms that you mention, the Multistar must have a gravimetric energy density greater than 224 wh per kg.
according to the specs I looked up for the multistar battery, it only has a gravimetric E.D. of 175 wh per kg. Pretty typical for a low discharge rate lipo, Which it is. price per KG is not much different, but quality is likely to be inferior to the Sanyo cells. at 10C discharge rate, it may be better for some multi rotors, but not for most UAV aircraft.
I'm not harvesting batteries from dead laptops. I'm purchasing the best cells that are commercially available from the most reputable companies.
All what you say is not true.
a good 18650 battery is about 3500mah @ 20A. make a 4s10p from those and you have a 35000mah @ 80A at a weight of 40*40=1.6KG. thats more than enough to run a dual prop 11 inch for about 200 to 300km.
Which specific 18650 is that? I haven't found one with those specs anywhere. Could you provide a link or complete number/letter designation?
Well explained! Thank you for all the information provided! 👍