Solved Battery size

[Mandoman21]

I’ve recently scratch built the sea duck and have it outfitted with the power pack c twin. The pack works great and I’ve had tons of fun with the guinea pig previously that I also scratch built. However it seems to be lacking on flight time and even after 5 min I find that the battery is warm and a little lower in voltage than I would like it to be. Like 3.27 v on a 2200 3s after 5 min of flying. I’ve wanted to upgrade to 4s for a while to get the extra power and flight time but am unsure which direction to go in terms of mAHs and the c rating. I’m a bit hesitant as I’ve burnt up a motor before trying to upgrade to 4s on a power pack b. I think the c rating was too high.
So to wrap it up I would like to know how big of a battery the c twin pack can handle in order to get longer flight times. I’m not worried about weight as the guinea and the sea duck are very powerful.

Thanks for your help!
Kendell

 

[Timmy]

I use two 1300 3s in parallel and that gets me about 7 mins flight time.

 

["Corpse"]

I’ve recently scratch built the sea duck and have it outfitted with the power pack c twin. The pack works great and I’ve had tons of fun with the guinea pig previously that I also scratch built. However it seems to be lacking on flight time and even after 5 min I find that the battery is warm and a little lower in voltage than I would like it to be. Like 3.27 v on a 2200 3s after 5 min of flying. I’ve wanted to upgrade to 4s for a while to get the extra power and flight time but am unsure which direction to go in terms of mAHs and the c rating. I’m a bit hesitant as I’ve burnt up a motor before trying to upgrade to 4s on a power pack b. I think the c rating was too high.
So to wrap it up I would like to know how big of a battery the c twin pack can handle in order to get longer flight times. I’m not worried about weight as the guinea and the sea duck are very powerful.

Thanks for your help!
Kendell

Don't worry about the C rating. That only means how much amperage the lipo CAN put out. You can run some transmitters with a high c lipo.

 

[Mandoman21]

I use two 1300 3s in parallel and that gets me about 7 mins flight time.

Do you think I could run two 2200 3s in parallel?

 

[Mandoman21]

Don't worry about the C rating. That only means how much amperage the lipo CAN put out. You can run some transmitters with a high c lipo.

Thanks, what should I concern myself with when choosing a bigger battery then?

 

[Timmy]

Do you think I could run two 2200 3s in parallel?

that would be quite heavy but the duck is made to carry heavy loads...worth a shot.

 

[BATTLEAXE]

I would be looking at what is causing all the amp draw. I can tell you like power and speed so for a 2200 3s you could step up to 4s and get that much more range out of your throttle. But if you are using C pack radials and 10x6 props I can see where all the power is being wasted. The motors are working to hard.

There are a couple ways to go about it. You could go with larger motors with the same 1200kv rating and run those props with a 40 amp ESCs to be safe. Or you could go to 4s with your current motor set up, still step up to 40 amp ESC, lower the pitch on the props. You should see some power gain and possible longer flight times there. Of coarse a larger battery would give you more time but you want to trim the fat off the system to find some real gains without damaging gear. Magic smoke

 

[Mandoman21]

I would be looking at what is causing all the amp draw. I can tell you like power and speed so for a 2200 3s you could step up to 4s and get that much more range out of your throttle. But if you are using C pack radials and 10x6 props I can see where all the power is being wasted. The motors are working to hard.

There are a couple ways to go about it. You could go with larger motors with the same 1200kv rating and run those props with a 40 amp ESCs to be safe. Or you could go to 4s with your current motor set up, still step up to 40 amp ESC, lower the pitch on the props. You should see some power gain and possible longer flight times there. Of coarse a larger battery would give you more time but you want to trim the fat off the system to find some real gains without damaging gear. Magic smoke

That makes sense, however in the release video of the sea duck (way back when Peter was still on the show) they mention flying the sea duck off of 4s on the river, without changing anything I assume about the setup aside from the battery size.

 

[quorneng]

Going to 4s with the same motor and prop will give you more power but it will reduce the duration unless you increase the battery capacity as well.
If you want more duration the best solution is to improve the planes aerodynamics and/or reduce the weight but if that is not practical then more battery capacity at 3s is the answer but bigger capacity batteries are heavier and that will cost you some performance.

 

[BATTLEAXE]

That makes sense, however in the release video of the sea duck (way back when Peter was still on the show) they mention flying the sea duck off of 4s on the river, without changing anything I assume about the setup aside from the battery size.

There are just so many variables to look at. More battery capacity=more flight time is the simple solution, but there is always a trade off. Like mentioned before larger battery is more weight to carry around, turns out to be less performance. If you are running a 3s hard and getting five minute flight times i would say you are on track. Remember going from 3s to 4s will give you 33% more effective throttle. If you treat the 4s like you would the 3s and run the plane at the same airspeeds then yea you will get longer flight times. If you run the 4s like you want a 6s then your flight time will be reduced, possibly at the cost of some gear.

It is usually the pitch of the props that draw the amps more then the size, number of blades makes a difference too. They flew 4s on probably 10x45 props which also works with 3s just at a slower more trainer like speed. If you are looking for more bang for your buck you could use the 3s system and step up to the 9x6 props and see how you like it, that is if you are using 10x45 now

 

[Mandoman21]

I’ve soldered up an XT60 parallel connector. I have two 1300 3s so I’ll give that a shot and also the 2200 3s.