Horrendous flight time!!

[Benjamin Kenobi]

Hey mate. I'd definitely throw that lipo away and unplug it! Move it somewhere safe!

I have a feeling that it hasn't been balance charging before and one cell was faulty so it pushed the other two cells way past their safe limit. Which also means they are damaged beyond repair.

I have never seen readings like those myself, ever. If I did I would be running outside with the lipo and grabbing a fire extinguisher.

Yes, I'm being serious! :nevreness:

 

[Benjamin Kenobi]

Of course there's always the possibility the charger is faulty? But I still wouldn't take the risk.

 

[cliofreak]

Yeah I think you're right. Thanks! Its been dodgy for the start. I'm gonna chuck it...expensive too!
So if I get something else, while I have your expert opinion, what might I purchase to get a longer flight time. If I could get 15-20 mins with the setup I have (mentioned in first post) then Id be happy! Maybe a pair of 5000 in parallel?

 

[Benjamin Kenobi]

Alas it doesn't quite work like that, double the mah, double the weight! A 5000mah should get you about 9 minutes. The best thing you can do to increase flight time is increase the cell count of your lipo. 4S got me a bunch more flight time compared to 3S. All depends what your system can handle though.

For the next lipo, balance charge it every time. See how much mah you put back in after a flight and work your flight time out from that. Remember the 20% rule (and learn it if you haven't already).

Have a look at the lipo brands and feel free to ask us to help you make a decision. I only use GensAce lipos since they are reliable and last forever, but they do have a high price.

 

[cliofreak]

Thanks Benjamin. So, how do I know if I can handle a 4s or more? How on earth do guys get 25+mins !? That would be amazing!

 

[Benjamin Kenobi]

No idea. 10 minutes is fine for me!

You'd have to research your aircraft and it's components to find out about 4S. Stick with 3S for now and get the hang of it. Had much flying practise with it so far?

 

[cliofreak]

Yeah, I can fly it no problem. Ive had a few frames etc (built my own once) but Ive only recently been looking at FPV. Ive gradually added to the build over the last 2 years and only recently had to move to a lipo more than 2200mah hence the problems with the 5000mah one. I have a full setup now with GoPro, gimbal, FPV and I just need to get it flying for longer. I thought 5000 mah3s would make a difference compared to the 2200 but it must have been a bad lipo or the lack of balance on first few flights has wrecked it. I'm very ready to move away from the beginner 2200mah 3S setup as its way too limited. Fun if you have a very light frame with no gear on it. My ESCs are 30A and I can't imagine they'd have a problem with 4s. Tarot gimbal might have an issue. It shares my main lipo.

 

[cliofreak]

Well the gimbal seems to be ok -

FAQ:

Q: How can I power my gimbal.
A: 3s is recommended, but 4s will also work. Use either a stand alone pack (600-900 mAh) or tap into your distribution board or main pack.

 

[Benjamin Kenobi]

Well I'd just make a little parallel harness and use two 3s 2200 ones then. I did this at first and it worked great! Cheap and easy solution.

 

[cliofreak]

Think i'll try that! Thanks. Ill post the flight time.

 

[Rotorfreek]

Where abouts are you based cliofreak?

Sent by my thumb, a trusty slave to my crazy mind. The above is the ramblings of a lunatic, and should be treated as such. Terms and conditions apply.

 

[cliofreak]

Derry in N.I.

 

[Rotorfreek]

I'm that case, in case your charger is due, this is cheap and very reliable:

http://www.hobbyking.co.uk/hobbykin...Cells_GENUINE_with_UK_plug_UK_Warehouse_.html

And id never not have a cell checker on hand. That way you can check what your batteries are really doing, and have a voltage alarm that's separate from the KK board that only does overall voltage. Cell checkers watch every cell, and if only one goes low you will know. Something like this:

http://www.hobbyking.co.uk/hobbykin...ker_with_Low_Voltage_Alarm_UK_Warehouse_.html

And finally, with an AUW of 1450g, my F450 With 920 kV motors and 10" props gets 20 min flight time until my alarm goes off at 3.6 volts per cell. That's on 5800 mah 3s Zippy. This one:

http://www.hobbyking.co.uk/hobbykin...0C_UK_Warehouse_.html?strSearch=zippy 5800 3s

So at 1600g you should get 15 mins. But to really gain time, you need to shed some weight, and get more efficient props.

Sent by my thumb, a trusty slave to my crazy mind. The above is the ramblings of a lunatic, and should be treated as such. Terms and conditions apply.

 

[cliofreak]

Amazing Rotorfreek!! Thats brilliant info. Ive just ordered that 5800mah lipo you recommended. Ill get the charger and the cell checker next week. So 1450 getting 20 mins. I can't really see how I an loose weight with the gear I have on it as the frame is light plastic however ill try. I wonder if 920v verses my 1100Kv will make a difference. I don't really want to have to change all the motors. Thats being said *confession* -

Ive been flying with three 1100kv motors and one 800Kv for about 8 months without it falling out of the sky. Should probably sort that out

 

[Rotorfreek]

What frame are you using? One of the main places I see people load weight on is their landing gear. Some of the gear sets I see on 450 size quads are ridiculous - very cool, but at the cost of overloading such a small frame, costing flight time. BTW, if you are FPVing, are you also using the go pro footage, or could you swap the go pro for a smaller FPV cam?

One of the best flight time improvements I ever found on a 450-500 size quad was trying the DJI 9443 NST props. I tried a number of 8 to 10" props inc all the big players, and the only ones that came close were T-motor ones. (But they are mega money...)

I wouldn't Imagen that using 1100 kV motors is any factor at all - although I wouldn't any more than 3S with 10" props. If you do try 4S, drop to 8" props. I would however change that 800 kV motor ASAP. Your FC will handle it, but that one motor will be reacting to FC inputs much slower than the rest. If you change it I bet you gain a good deal of stability in the wind.

 

[cliofreak]

What frame are you using? One of the main places I see people load weight on is their landing gear. Some of the gear sets I see on 450 size quads are ridiculous - very cool, but at the cost of overloading such a small frame, costing flight time. BTW, if you are FPVing, are you also using the go pro footage, or could you swap the go pro for a smaller FPV cam?

One of the best flight time improvements I ever found on a 450-500 size quad was trying the DJI 9443 NST props. I tried a number of 8 to 10" props inc all the big players, and the only ones that came close were T-motor ones. (But they are mega money...)

I wouldn't Imagen that using 1100 kV motors is any factor at all - although I wouldn't any more than 3S with 10" props. If you do try 4S, drop to 8" props. I would however change that 800 kV motor ASAP. Your FC will handle it, but that one motor will be reacting to FC inputs much slower than the rest. If you change it I bet you gain a good deal of stability in the wind.

Im using this http://www.hobbyking.co.uk/hobbykin...er_Quadcopter_Frame_w_Camera_Mount_585mm.html

Its 680g all in I think. I can't see one on Hobbyking thats better, apart from one thats 40g less. All the lighter ones are 250/200 size quads. Yes, I'm using the footage frome the gopro 3+ so I need to keep that. In fact, Im going to have to add a cmos cam to the weight because the go pro is on a gimbal and I presume fpv via a level gimbal would be disorientating. I will change that motor and you're right, in the the wind its unstable and tricky to catch back on track. I can't se anything I can take off the frame except maybe the rods on the feet. They could be cut but probs only worth 20g.

 

[cliofreak]

I found this very interesting - http://www.********.com/forums/showthread.php?t=2083128

The Phantom is only 590g with everything including FC, motors, props, power board etc. Is there quad frame available (with legs) that can take a tarot gimbal that weighs less than 660g with everything except the battery...just like the Phantom? It seems I'm trying to get phantom flight times but with way heavier frames. This Phantom is under a Kg with a big 5300mah battery. Thats impressive! I want that...but in a self build. Is it achievable?

 

[Rotorfreek]

I don't see how it can be done for less...

Sent by my thumb, a trusty slave to my crazy mind. The above is the ramblings of a lunatic, and should be treated as such. Terms and conditions apply.

 

[Rotorfreek]

No legs I know, but the original F450 ones only weigh 48g, and can be less of you cut carbon plate to extend the legs built into the arms.

And lighter than the P2 [emoji12]

Sent by my thumb, a trusty slave to my crazy mind. The above is the ramblings of a lunatic, and should be treated as such. Terms and conditions apply.

 

[cliofreak]

Wow, thats class. Im considering drilling a series of holes in the arms of my frame and cutting off all the surfaces that I don't need...also taking off the feet and chopping the legs till the gopro just rests on the ground. I had a f450 style frame before and I was getting 9mins with a single 2200mah. I had no gimbal on it and no camera. I wonder if I should go back to that setup and but feet on it and try to mount the gimbal under it. Since Ive had this new frame and gimbal, its been pretty unusable.