Anyone got battery recomendations?

[AxeGrinder]

Hi...

I have tried a LiFE 30-40c 3400mAH 3 cell 9.9v unit, which powers up and runs my quad ok, but it's not good... lasts about a 3 mins at 30%-50% power, before 1st ESC trips out on low power @ about 8.4 volts. 30 amp Red Brick ESC... so I'd never trust this battery for flying...

So, I'm thinking about a dual battery option... Will be LiPo this time, 11.1v, min 30c.

So, my questions are, can I run higher discharge without damaging anything, say 50c? Can I run 5000mAH ? Can I use 2 x 3400mAH/30c, linked in parallel? Can I use 2 x 5k?

Are there any good makes, or in particular, any I should avoid? Cost is obviously an issue, however, if lighter weight units are available, I'm all for that... here's my chopper, runs, but not set up right yet, keeps flapping or flipping altho I can stop flipping now!

Very much a prototype now, eventually, it will have proper mounts for the motors and the CF "rails". The alum section, which is perfection for mounting batteries and suspending a camera system (found in a skip) will have the guts drilled out of it to reduce weight and a nice finish put on it, and the wiring is run thru the slots inside the channel., hopefully, I can run the motor wires through the CF rails, hoever this will mean cutting or drilling them. Rails will be painted dayglo green and red, as shown by heatshink, thus indicating forwards direction.

 

[holtneil]

hi mate i use 3 cell 2200 mah nano tech battery on my quad and are very good dont even get warm and are 45c /90c burst , some times one big battery is better then two just look at weight of a single compared to the two , you can run higher c rating your esc / motor will only pull max when it needs to and its normally for 15 seconds thats the burst rate li fe battery is normally used in trans lipo are a much better battery i use the nano tech as good price for what they are just charge at 1c , What fc board are you using and prop size can make or brake a quad , i first had 9x4 blades god no lift now i run 10x4.7 lift is great its a heavy quad but i still get 5 mins very hard flying or 6 mins gentle , my boy has light weight quad runs on a 3cell 2200mah 30c/40c and he get 10 mins flight time , i will put a link on here so you can play with prop sizes and battery size will give you a hover time or flight time so you can see also props make the times change
Also have you checked it is balanced in it middle a H quad like all quads have to balance if you fit a camera you need to move battery to balance it again , when you set up fc board you have to do a calibration so it need to be level so the board knows what is level, i use the kk2 board so easy to set up and can run camera gimbal too ,
one word of warning the plastic blade can get stress fractures in them and snap in flight, before you fly look at under side of blades next to the hub for white marks this is a stress fracture starting , some blade like plastic ones will make the quad wallow if you stop movement fast, carbon reinforced blades are better , but the best is carbon fibre blades very light and no flex and they come as big as 15x5 ( first number is size second is pitch sorry if you know this already) let me know how you get on the H quad looks good
just a thought is the board the right way round should has a direction arrow on it for forward ( some boards are at an angle when in the right position) any way the link good luck happy flying
http://www.ecalc.ch/xcoptercalc.htm?ecalc&lang=en

 

[AxeGrinder]

Good reply, thanks! Looks like I can go as high as a pair of 4500's if I needed long flight time... and perhaps my life battery is not doing so bad.
calculator
My props have chunks out of them... no point even balancing them... but they give an idea of what the chopper is doing for set up purposes... will not try to fly with these props... waiting for a new set of 11 inch props to arrive, ordered a few days ago... your web page link agrees with my earlier calcs that this is most efficient size with 81.4% efficiency @ max power

the machine is set up fairly well balanced, altho battery could be 1mm off center... Battery wires prob compensate for the weight of the receiver. With two batteries, I can mount my camera centrally, and balance it with a battery either side... or locate cam at one side and balance with batteries on opposite... should work quite well

Yup... machine has correct direction set up... waiting till tomorrow to test again, as the dog does one when I start her up!

 

[holtneil]

HI mate my dogs run for the hills when the quad or heli comes out , so what blades did you go for , the carbon reinforced blades are prone to chipping , thats why i only fly on carbon fibre i use gemfan blades they are very well balanced , i know in the USA they do up to 15 inch blades
10x4.7 are the biggest i can get on my quad , i love the sound of the blades as you pull hard turns they growl really nice lol
Please keep us posted on how you get on , it helps new flyers having seen what you have done and some may copy your set up kind regards neil

 

[AxeGrinder]

Have been messing about with the calculator... 4 blade props can give 84% and good flight time... interesting... not really much gain with 3 blades...

I've ordered a set of plastic red/green props 1047 for learning to fly... and have a set of 11 inch CF coming from China... be lucky to get them before NY... But that will give me plenty of time to get a safe hover going... Think I need to reverse my pitch giro, as it's started oscilting fore to aft... may try whenbattery is recharged... ha, thats next on the order list... and decided to go with Nano's, as I read a great article about batteries and it gave them a terrific write up, prob a 5000mAH 50-80c.

Everything you wanted to know about LiPo's, here: http://www.rchelicopterfun.com/rc-lipo-batteries.html

I checked 15" blades, which will fit my chassis, on the calculator... I have pretty good strong motors, yet the bigger props reduce all power outputs and efficiency. My model would require significantly larger motors for 15" to work well, however, the payload is 2.5-3kg and 90% efficient altho flight times suffer... 15" 4 blades next...HA BIG motors

 

[holtneil]

HI mate yes big props need a low kv motor that has lots of torque, i will put a link on for bruce he does very good videos on every thing rc all the basic stuff too, The nanotech battery are good i love them use them for ages now some can take a fast charge at 1.5 c but check first on the back of battery it will tell you , they do say if you go 3 bladed prop to go down an inch on size, now for bruce add him to your watch list he has 100s of videos scan through and watch the interesting ones

 

[AxeGrinder]

Yeah... 3 bladed props don't amy real benefit anywhere... something I looked into a while ago, but the numbers on the 4 blades are sweet! may start looking at fans

 

[holtneil]

The ecalc site is very useful saves time and money , keep us posted on your finding mate ,

 

[QuadrocopterCanada]

Please let me know, if anybody would like to try LiPo batteries from AgaPower. I do have several for Quads and for FatShark FPV.

 

[holtneil]

Love too but shipping would be a night mare