# How to choose battery capacity for longer flight time

Larger battery allows for longer flight time. Unfortunately the increase of flight time isn’t proportional to the increase of battery size, which means you are looking at something like this.

Before we begin, make sure to read the basics of LiPo battery for drones.

As the battery gets larger, the increase in flight time becomes ineffective. Eventually it will reach a point where it just doesn’t gain any more flight time with bigger battery (even lose flight time). This is mainly caused by the weight of the battery. Also note that the heavier your copter gets, the less agile it will be. But some people prefer the stability it brings with heavier weight, some would call it “flies like a tank” :). Apart from capacity, there is also C-rating you need to consider, which I shall explain later.

The trade off between flight time and battery capacity, makes it more difficult to choose which battery should be used, rather than just “pick the largest battery available”. There are techniques you can use to help with this selection task – creating graphs and mathematical model in Excel, which I found really useful when comparing various products of the same kind. I recently bought some 4S batteries for my FPV tricopter, I will use this as an example. This technique should be useable for any multicopters, including the 250 mini quad.

Talking about Batteries, here is a tutorial on how to do LiPo parallel charging.

# List All Batteries and Create Graphs

First, list all the batteries with different capacities, brands of the same cell number. You can include their weight, price, etc in your table. For example I was looking for 4S lipo battery for my tricopter and here is the table I created.

### Max Current Draw and Battery C-Rating

It’s important to note, that the batteries you listed can supply enough current for the motors. Max current supplied by the battery can be calculated by this formula:

`max current = capacity * C-rating`

First, work out what would be the possible max current draw from your motors. I usually just look at the motor datasheet, which should tell you what the current draw is at 100% throttle, times number of motors, and add some margin for other electrical parts, and you have the possible max current draw from your quadcopter.

My tricopter has a max current draw of around 30A – 35A, and all of the batteries below meet the requirement.

### Listing batteries and data

From these data, you can create some very interesting and useful graphs, for example I usually do

• Density, which is capacity per gram (= capacity / weight), and
• Value, which is capacity per dollar (= capacity / price)

From the above graphs, if I am only going for best performance and not worry about the price, I would definitely go for 2650mah, 3000mah, or 3300mah. Also 4000mah might be a good choice too due to its outstanding value.

These graphs tell you some insights into which battery has the highest price/performance ratio, but it doesn’t tell you whether this is the best battery for your RC aircraft, quadcopter or tricopter. To do that, we need to create a mathematical model.

# Build Mathematical Model to Estimate Flight Time

This is actually pretty fun to do. By using this model, you will be able to calculate the flight time of any battery. All you need to do is to put in the data of that battery in the excel spreadsheet. Of course, this is only an estimation, but it does give you an rough idea what battery to go for, and save you from spending too much money and time to try each type.

First of all, you need to get one battery first, and collect data using it. Basically the data we need is flight times under different loads. You can of course collect some other data as well to help you identify what is the max load your multicopter can take, for example, the throttle value, current etc.

In my example, I used a 2200mah 4S Lipo Battery as a reference, and tested the flight times under different load weight (0g, 110g, 220g, 340g, 405g, 515g – all these weights are physical items I can find in the house that’s why the uneven numbers). This is the data I collected from 6 test flights.

I always land the tricopter when the voltage alarm beeps, which is when the voltage reaches 3.5V per cell. The column “Actual Capacity Used” is not really needed, but I collect it just to make sure my data is valid. I got that from my charger, when I charge it fully at 4.2V per cell, I know what capacity was used in the previous flight. I then work out “mah / second”, which is the speed of power consumption, and we can draw a graph from this.

The good thing about Excel is, it provides an equation from a few dots on the graph. This is probably should not be a linear relationship, but the battery weight falls within this range so it’s close enough for me.

So here is the model. “Cap at 3.5V (86%)” is the effective capacity that can be used during a flight. I am making an assumption that the voltage drops down to 3.5V when 86% of battery capacity is used. “mah/s” is calculated from the above equation, we can work out the mah/s for each battery, depends on their weight.

And now the estimated flight time is roughly equals to effective capacity divide by mah/s. For example for the 6000mah battery, the effective capacity is 5160mah, and the speed of power consumption is 5.75mah/s, so the flight time would be 898.16 second which is nearly 15 mins.

When I worked out all the flight times, I found this interesting relationship between size of the battery and flight time. That’s exactly what we predicted at the very beginning.

That’s the analysis I always do when buying batteries. I made a lot of assumptions above, so also do your research on the flight time, ask people for their experience, to verify your theory.

Let me know if there is any mistakes in the method, or any better ideas.

20th September 2022 - 12:05 pm

How long a battery of 4500mah will help a drone to fly using 4 motors in it also I am using a flight controller APM 2.8,40A ESC.

24th August 2022 - 8:08 am

Hey hi.I want to use a battery for an octocopter i have been thinking to design.The problem is I need some reference to back up the battery calculations.Can u suggest me any reference which u have found out while researching about calculation of battery and flight time.Thank you.

17th March 2022 - 4:17 am

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18th July 2020 - 3:15 am

I am using four 1400kv brushless motors
Four 30A esc
Cc3d flight controller
I want 30 min flight time
Can you suggest me a battery

2nd January 2020 - 6:26 pm

hoi
ik heb een kit gekocht 360mm glasvezel
het gewicht is zonder battery en voeten 650gr
motors 920kv en 30A esc
ik kreeg er een 3s 3300mah 25c batterij bij
krijg het niet de lucht in , zou ik voor een 300mah 4s gaan 45C ? ook om onder de 1 kg te blijven
en wat is de vliegtijd aub ?
dank u.

21st February 2022 - 7:26 pm

Need help trying to figure out what I can use my 3.7v 5000 mah Lipo rechargeable batteries….I bought for my AKASO-UFO a31, it uses a 3.7v 750mah and last maybe 11 or 12 mins. Ifigured if I bought bigger battery it’d go faster and last longer. Needless to say it wouldn’t hardly leave ground but had noticeable more power. Didn’t figure the weight would matter a lot but it does. The propellers are doubles not triples…would it help to change propellers or motors? Could I buy bigger motors to change out and if so what size?

1st September 2019 - 4:41 am

Hi Oscar;
I kind of new to 500mm Multi-rotors, building my first one. In this article about “how to choose battery for quad-copter, under “Tricopter Hover time against Weight” Table, you mention about always landing the Tricopter when the “voltage alarm beeps”…? I have one, it’s a “RioRand RC Model Hop-ups…Checker +Warning Buzzer”(Lipo Battery Voltage Tester, Low Voltage Buzzer Alarm” it’s got 10 Pins, 3 Digital LED’s & 2 Beepers, 1-tiny push button to select the Mode. Handles 1S to 8S, Set Alarm Value range: OFF, 2.7-3.8V, when voltage drops below set value, Buzzer/Beeper goes off w/Red LED Light.
Was wondering if mine was like yours, that I assume you have mounted to your Tricopter..? If so, is it possible to mount mine on my Quad-copter where its visible…? And how would I wire it & to what….? Thanks in advance,
James…..

10th September 2019 - 6:11 pm

Sorry i am not familiar with the alarm system you have. Maybe try posting it on our forum (intofpv.com) with a picture see if anyone knows how to configure it there?

21st May 2019 - 4:54 pm

Oscar, your killing me…. I’ve read this post about four times.. I like to geek out usually just as much as the next guy but I can’t wrap my head around this.

I too I’m trying to find the optimal battery for long flight times with a balanced performance on a 7in 4-6s quadcopter.

I built a spreadsheet defining 4, 5 and 6s and their Associated weight and watt hours. But because I cant figure out how to calculate how many amps my quad draws, I cant make an absolute choice. Any help would be appreciated.

Xing 2207 1700kv 32.2A at 100% thottle.
Total weight of quad with GoPro and no batt = 625g w/batt = 996g (batt=2200mAh 6s)

Even if I don’t get a reply from you I just want to say thank you so much for all the valuable information you have provided to the community it has helped me in so many different ways!!

Hazz

19th April 2019 - 9:12 pm

Hi,

I was wondering whether for the graph shown in the “Listing batteries and data” section (the first graph that shows the relationship between battery and weight) you have the battery types associated with the capacities as well (e.g. AAA, …)? And also, do you have more comprehensive list of battery weights, sizes and their capacity by any chance?

1st January 2019 - 12:08 pm

Hello!
I ordered my first micro racing Kingkong 110GT and it has a lot of noise at full throttle apparently because of the battery. Stock battery is 2S 350mAh 35C.
Lumenier 400mAh 2s 50c and
Lumenier 450mAh 3s 35c Lipo.
How would the 3s perform against 2s 50C? Any other mah you would buy for this micro?
Thank you!

1st January 2019 - 12:32 pm

Going up in cell count basically increases the voltage, and motors will spin faster with higher voltage, making it more powerful.
You need to check if your quad can support 3S, such as your motors, ESC and other components if they are also connected to the LiPo directly.
If your quad is already very noisy with 2S, it will only get noisier on 3S because the motors spin even faster.

26th December 2018 - 12:18 am

You have great content here! Most of the blogs lack of technical information and calcs! Gratz!

9th August 2018 - 5:34 am

I have a 210 quad with 2205 2300kv motors, as per specs motors draw 20A per motor.
My lipo is tattu 3300mah 35c 3s.
I already flown it for few times, I get around 10 minutes of flight time. I am happy about the way it flies and flight time.
lipo get lightly warm(95F) after 10 minute continuous flight time. At rest Lipo was at 84F.
My question is, is it ok to continue flying with above lipo?

11th August 2018 - 4:29 pm

95F is about 35C… this is not even considered warm :D
Don’t worry it should be fine, it’s normal for LiPo batteries to get even warmer after discharging.
According to sources on the internet, LiPo has a safety temperature range of 0C to 50C (122F).

21st May 2018 - 3:18 pm

Some drones have there one rechargeable battery so how do I change that to last longer.

24th April 2018 - 4:42 pm

Hey what battery would you suggest with this setup. Iv been running 5s and 4s and the drone cruses at around 109mph and at punchout does 124mph. My flight times have been very short even cruising around no punchouts. On average i get 2mins flight time with 5s when im on the throttle real hard i get arpund 1 min 30second and the batteries come very hot keep melting cells im serious this thing kills atleast 2 battery cells per week. The 4s batteries are 1550mah 95c and 4s 1500mah at 100c the 5s are 1300mah at 95c and 5s 1300mah 80c just messed up the 5s 80c yesterday has a dead cell now brand new battery flew it maybe 3 times i always come down when the cells are at 3.5v no lower i have 2 different battery power in my osd and a physical voltage alarm attached to the battery all set for 3.5v but i keep frying them. My setup is 4 motors type is f40 pro II 2600kv dalrc 40a esc with 50a burst. Total weight of quad without a battery is 298grams its a 5in mach1 RDQ frame. But what battery size should i be running i do have a few tattu 1800mah 75c 4s batteries the same thing on those blew one side of a cell out last week on one of those. Would like to get this thing in the air lo get than 2 mins max so i can complete a race. Because this thing is a beast i know on 5s this thing is way faster than 4s at 124mph i have not had it clocked on 5s yet but its way faster than the 124mph im sure its hitting in 150mph area because it get so fast the stability is not right and it handels real wierd at those speeds so im going to be racing the 4s and only run the 5s for fun or if im just showing off lol. But what size should i use on a drone pushing 160a to 200a max draw that is all 4 motors combined or 40a a motor to 50a a motor. I cant seem to find one that discharges enough that it doesnt kill the battery.

30th April 2018 - 4:07 pm

For the kind of speed you are after, it’s pretty hard to get any more flight time without using bigger packs. 100MPH for cruising is pretty hard on the battery.
What props are you using? and What sort of current do you draw when cruising, and punching out?
I think you should be looking at changing your setup for the type of flying you do, not the battery.

23rd February 2018 - 4:37 pm

hi…i am planning to buy batteries for my fixed wing plane mission ..the requirements of mission states that the flight time should be 45 mins .
the specifications of the electronics are :
SunnySky X2814 KV900 Outrunner Brushless Motor x2
40a escs x2
Model: X2814-900KV
KV (rpm/v): 900
Weight: 106g
Diameter: 35mm
Length : 52.1mm/ 34mm (with shaft/ without motor shaft)
Motor Shaft Diameter(mm): 4
Prop adaptor output shaft diameter: 6mm

well what mah battery will be suitable for carrying my mission out if my max payload capacity is 3-4 kgs

11th January 2018 - 12:25 pm

Hi
I want to buy a battery for my UAV with fixed wings with a brushless motor:
6s 22.2 V
kv = 420
Imax = 70A
efficiency = 0.9

MY ESC is
I = 80 A
U = 22.2 V (6s)

What battery should I choose?
I need a 30C and I need to fly 100km.

13th July 2018 - 10:41 am

Use 10,000mah 3.7v 3s lipo betrry and feel better experience

3rd June 2017 - 5:36 pm

Hi Oscar,
I read your infos about LiPo batteries and I would like to share with you my difficulties.

I am building a quadcopter with these specs:
X conf, 500mm aluminium frame;
4x Flycolor ESC 20Amp;
4x MultiStar motor 935KV (15Amp Max);
Propeller 10×4.5;
Weight 1250g.

I had bought a 3S LiPO 5200mAh 10C (Discharge max 20C). I am just doing some stabilization-test but the battery already last short and it seems that one cell is ruined (the voltage level is always lower than the other two). Moreover, I can not charge it above 11.3V.
Did I choose a wrong battery?

I am looking for a new one, founding the list below. Which one would you suggest?
Turnigy nano-tech 4000mah 3S 25~50C Lipo Pack
Turnigy nano-tech 4000mah 3S 35~70C Lipo Pack
Turnigy 5000mAh 3S 20C Lipo Pack
Turnigy 5000mAh 3S 25C Lipo Pack

Is it correct that the 5000mAh should last more than the 4000mAh even with higher C-rate?

Thank you very much for you help!

9th June 2017 - 8:35 am

Hi Simone,
Of course your battery will short !!! your battery can discharge maximum 52A only while your motor draws 60A.

The c-rate WILL NOT affect the flight time. So both 5000mah have same flight time and of course the battery will last longer than the 4000mah.

23rd November 2016 - 12:29 am

Hello,

i want to build quadcopter with this parts:

Motor specs-
A2212 / 13T 1000KV Brushless Motor Outrunner

80% max efficiency
4-10A max efficiency current
No Load Current: 10 V : 0.5 A
12A / 60s current capacity
2-3 Li-Poly cells
Model: A2212
KV: 1000
MAX Efficiency: 80%
MAX Efficiency Current: 4-10A (>75%)
Current Capacity: 12A / 60s
No Load Current: 10 V : 0.5 A
No. of Cells: 2-3 Li-Poly
Motor Dimension: 27.5 x 27mm
Shaft Diameter: 3.17mm
Weight: 48g
Package Weight: 59g

ESC-
Wolfpack 30 Amp ESC

Output: Continuous 30A, Burst 40A up to 10 seconds
• Input Voltage: 2-4S Lipo, 6-18 cells NiMH
• BEC Output: 3A / 5V (Switch Mode BEC)
• Refresh rate of the throttle signal: 50Hz – 400Hz
• Max Speed: 210000rpm for 2 Poles BLM, 70000rpm for 6 poles BLM, 35000rpm for 12 poles BLM
• Size: 73*26*8(L*W*H)
• Weight: 38g

Flight controller – Naza M lite

AUW-1500gms (FPV included)

Battery ?
C rating-
mAh-

Should i go for –

Orange 2200mAh 3S 30C/60C Lithium polymer battery Pack (LiPo)

Or

Orange 3000mAh 3S 30C/60C Lithium polymer battery Pack (LiPo)

Or

Orange 5200mAh 3S 40C/80C Lithium polymer battery Pack (LiPo)

Battery Charger ?

SKYRC IMAX B6 CHARGER

Operating voltage range: DC 11-18 Volts
Circuit power: Max. charge power 50W
Max. discharge power 5W
Charge current range: 0.1-5.0A
Discharge current range: 0.1-1.0A
Current drain for balancing Li-po: 300mA/cell
NiCd/NiMH battery cell count: 1-15cells
Li-ion/Fe/Polymer cell count: 1-6cells
Pb battery voltage: 2-20V
Net weight: 277g
Dimension: 133x87x33mm

Battery ??????????

29th December 2016 - 12:33 pm

I would suggest starting with a ‘good old standby’ cheap battery like a Zippy 5000mAh 3S 30C. Your max current draw with 4 of those motors is only 12×4 = 48amp, and that is full throttle max load. At 1500g all up including battery you should see around 9 minutes of flight drawing down to 10.6 or 10.7 volts. I built a 450 quad (cheap ebay RHD 2212-920kv motors, 1045 carbon fiber props, ZMR450 frame, SimonK 30a Mystery ESC, M8N GPS, pixhawk controller, SiK telem, FPV) that is 1375g including a 3S Zippy 5000mAh 30C, and I get 10-12 minutes of smooth, easy “camera platform” flying on a loiter or position hold mode. 7-8 minutes if I fly it hard in acro mode.

Your motors are 1000kv, I would suggest a 9″ prop instead of the 10″ that I run. Be sure to check/balance all your props. If you’re new, get plastic/nylon props. After you get the hang of it, switch to carbon fiber props. You’ll notice a difference in sound and response…and a little in efficiency.

I use imax b6 chargers too.

Good luck, happy flying.

The FlyNfool

26th August 2016 - 7:53 pm

HI
i am making quadcopter using kk2.1.5
motor A2122 1400kv max current 16A

THEN
3s 3000mah 20c battey is best

27th October 2016 - 6:30 am

How did you compute the flight time? what formula did you used? thankyou in advance

3rd July 2016 - 5:13 am

HI. I have the robocat racing drone. (Got it as a kit)
I have a 20amp esc x4 (80amp total)
The only thing I have to understand is what battery should I use.
I tried 1200mah 11.1v 25c
Won’t work good…
Now I ordered 2200mah 11.1v 35c
Will it work?

8th September 2016 - 10:23 am

Battery capacity * C-rating rate MUST be ,more than motor current draw otherwise your battery would deteriorate very quickly. Try using larger props. If you have a heavy drone then use low KV motors as they provide more torque. My Flying 3d x8 is about 800g and uses 935 KV motors.

4th October 2016 - 6:16 pm

Use 3000 mAH bettery with 10X45 props.

7th March 2016 - 4:45 am

Hi Oscar.
This is one of the best explanations that i have come across so far. Really useful and informative for beginners.
I’m trying to build a micro quad around 100-150g. Can you suggest the optimal battery, motor’s and prop that I can use.
If you can give me the details i would be really glad for your help.
Thanks.

29th February 2016 - 8:12 pm

Hi Oscar,

27th February 2016 - 10:11 am

Hi Oscar,
i have a2212 brushlees 1000kv motor with the following specification:-
Specifications:
– A2212 1000KV
– RPM/V :1000
– Stator Diameter(mm) :22
– Stator length(mm) : 13
– Stator Arms(mm) : 12
– Magnet Poles : 14
– Motor Winding : 22
– RPM(KV) : 1000
– Idle Current(A) : 0.55/8
– Max Current (A) : 17
– Max Power(W) : 190/3
– Rotor Dia(mm) : 28
– Shaft Dia(mm) : 3.17
– Motor Length(mm) : 28
– Overall Length(mm) : 42
– Biggest Thrust g/S : 1200/4

i want to know that how much mah & discharge rate battery would be required for this motor where i have 30a ESC

17th January 2016 - 6:41 am

i am using 1200 mah for my tricopter,

motor: 1200 kv. max current 16 A and for 3 motors 48 A

But battery can give only 30 A,

is this is the problem or i can use it,

my copter is just rotating on the ground and not fllying. all the setting i have done correctly. i am using kk 2.1.5 board

24th January 2016 - 4:22 pm

Hi, Puvan, im not sure about this. try 20A/30A esc or change bigger props. Might be esc was very low and your drone very heavy. My setup drone X525 quite big drone around 600gram to 1.5kg/2.5kg can lift very fine with 3S 1500mah but respond quite slow also to lift slow too, and drain fast. My ESC 30A. Duration test no camera 3s 2200mah 30c old battry around 5minutes / New 3s 2200mah 30c 11minute / Parallel New 3s 18/22 minute. “Guest what near 30Minutes”

22nd February 2016 - 5:22 am

Hi puvan,
Uh… thats a negative, ghost rider… your batt is taxed. If you are running 3 motors for a total of 48 amps and your batt only delivers 30 amps, major problems WILL happen. Lets add it all up… 48 amps for motors, a few amps for the FC, a few amps for the radio Rx, some “head-room” usually 5 to 10 percent… So far, we have roughly 52 amps for basic gear, 5 amps for head-room, for a total of 57 amps. I would round that up to 60 amps. Your battery should be rated to put out at least 60 amps continuously… NOT peak rating. For example: 1300mah 45C to 90C. Move the decimal over to the left 3 spaces to convert mah to amps like this: 1300(.0)–> 1.3 amps. Now multiply 1.3 x 45C. The first number in C rating is constant rating, second number is peak and the battery CAN NOT run that much current for very long. So we get 58.5 (amps) and 117 (amps). So now we know that the example batt will deliver up to 58.5 amps continuous and 117 amps peak, for extreme manovers and punch-outs.

ALWAYS make sure your battery can deliver more amps than you can use. I like to look at my flying and figure where I spend the most time at what throttle position and either bench test motors and props I am using or look for a data table online and figure out what my motors are pulling at said throtttle position, then do the math as we did above and match a battery with the first, low C rating equal to or larger than the amps I calculated.

Blue skies, Brother and good luck

11th January 2016 - 5:35 am

Hi Oscar,
We are use 8, 1300 kv bldc motor for multi copter and its maximum current rating is 50~60 amp and produce thrust is 1860~2400 grams, so how many mah battry is suitable for long flight time?
Pleas riply as soon.
Thank you.

4th January 2016 - 9:19 am

Hi Oscar I am building my first quadcopter.
I want suggesion in using components like propelers,frame,esc,motor,battery.
mainly I want to build flight controllers,transmitter and reciever so please help me by sending details needed for that.
I am unaware of most of the things so please tell me details.

9th November 2015 - 6:29 am

Hi Oscar,
I think there is a mistake on your choice of batteries, you mentioned that you prefer performance rather than the price, but the batteries you chose (2650mah, 3000mah, or 3300mah) have more density and are cheaper than other batteries in the list. it seems like those with higher capacity and less weight are more expensive.

26th October 2015 - 2:42 pm

Hi Oscar,
thank you very much for this detailed and usefull article and more generally for your awesome blog. I love it ! One of the best I know so far about quadcopters and FPV… even though I am really new to hit as I finished mounting my first quad last week :). Nethertheless I spent several month diggingintensively on many forums, blogs and websites before buying my forst quad.
I built an Emax Nightawk 280 with 12A BLHeli ESC, Emax 1806-2280kv, Naze32, FrSky Taranis X8R (coming with the Taranis, but will most probably change for D4R or X4R), Gemfan 5030 props, 1350mAh 3S 45C lipo, Skyzone 3D camera, Skyzone SK201 dual video transmitter, for a total of 550 g (battery and HD AEE cam included). My problem is that I got a really really short flying time of only a couple of minutes (and when I say a couple… I really mean a couple : 2 ) and that is when removing the AEE camera. I guess it could come from the FPV setup but I was wandering if you had an idea of what could be the problem and if you could cue me on how to solve it. I guess using a 1800 mAh lipo would help, but do I need to choose one with higher C ? I might switch to a more classical FPV setup to try if it is the problem. Regarding the specs of the FPV, it should not draw that much power (5v/0.5A, 1.6W for the camera, 12V/1.5A 7.5 W for the Tx)…
Any idea ?

28th October 2015 - 5:25 pm

What’s your total weight of the quad? I think you might want to try 6030 props with might give you a bit more efficiency.

30th October 2015 - 9:02 pm

It is 550g including a 1350mah Lipo. 442g without the Lipo.

30th September 2015 - 7:01 am

Hi, i am actually a noob at this so i am asking myself how to build a quadcopter, i just got the motor antigravity 4006 T-motor, prop eller 15*5″, ESC T-motor AIR 20A, and a PDB with max 100A, but i am lost about what battery should i get? somebody could help me this is a project for a class so, i am kind of lost and almost out of time, i have like a month or 2 to do this. i would be really greatful if someone can help me out!

30th September 2015 - 7:03 am

i think that my Quadcopter weigth is going to be 2.3 – 2.5Kg

15th December 2018 - 11:38 am

my current one weighs 3,2kg and i have flown heavier just remember to make sure you have enough thrust to lift it plus extra ;) im currently making a model dji inspire 3dprinted parts and will be switching my hardware to it and will end up weighing 1.9kg roughly give or take frame and body only weighs 700g so far so i hope its lighter than my curent one after the dji my next one im looking at is custom built i have plans but is almost a 1.2m diagonal so that should be a fun one to fly

29th September 2015 - 8:45 pm

“Hi Oscar” I wanted to make a hexacopter which will have around 3-5 kg of payload and flight time around 30 min,so for these purpose which batteries i can use ?

5th September 2015 - 7:16 am

Hi Oscar

I am building my first multirotor. I 3D printed all the parts except the aluminum booms. It it a T shaped tri motor. Without the battery it weighs 506 grams. The motors are Multistar Turnigy MT2213-935KV with 10×4.5 props. The ESC are Afro racing 20A Linear speed controllers, It has a KK Mini flight controller and an Orange 615X reciever, I ordered a Multistar High Capacity 3S 4000mAh Multi-Rotor Lipo Pack. The battery weighs 244 grams and is 10 C. Is this OK? I plan to get other batteries too but I want to know if I Have selected the right size. Here is a picture http://i287.photobucket.com/albums/ll144/Peterthinks/130_0492.jpg The motors are 545 millimeters apart. If you ever want anything 3D printed send me an email I will do it for you, I appreciate the time and effort you have put into making this information available.

Peter

7th September 2015 - 12:31 pm

Very very nice Peter :)
But your choice of battery is a bit too low in C rating.
Not sure exactly how much current your motor/prop will draw without testing, i guess around 15A on 3S at 100% throttle? so max current is 15*4=60A.
For 4000mah you are looking at 60/4=15C

30th August 2015 - 7:27 pm

Hi Oscar

Im about to build a quadcopter but Im not really sure about what parts to use… The man question Is If The PCB on the tarot 650 sport is enough or do i need one mor externa? Also how i get it to works with The motors ive choosen and The flight controller.. since the motors need 22.2V and the flight controller, gps, receiver and so on is about 5V
It would men alt to me If you would like to help me with this!

Heres the parts:

Motors: banggood.com/Tarot-6S-380KV-4008-Brushless-Motor-For-RC-Foursix-roter-Multicopters-p-936812.html

Flight controller: banggood.com/Tarot-ZYX-M-Flight-Controller-GPS-Module-PMU-Module-USB-Module-ZYX25-p-980863.html

Esc: banggood.com/Hobbywing-XRotor-Pro-40A-Brushless-ESC-DEO-2-6S-For-RC-Multicopters-p-992316.html

Battery: banggood.com/ZOP-Power-22_2V-8000MAH-30C-Lipo-Battery-XT60-Plug-p-990752.html

Cheers!

26th December 2015 - 6:43 am

Andreas,
The PCB on the 650 sport will be just fine. My 650 sport pulls almost 80A @ 15V at full throttle, never had a problem with the built in PDB. Trust me full throttle is rarely needed. Since your using higher voltage its even better, less amp draw.
Everything you list looks fine. The X rotor ESC’s are great, one of the best on the market. Very fast switching speeds and strong dynamic braking. Big plus that its 6s capable.
You failed to mention your prop size. Thats the critical component. Id imagine a 15×5 prop would get close to being right.

20th July 2015 - 5:40 am

i am expecting build quad copter with below mention items.what is the suitable batter for this.pls help me.

NEW 4Set 1806 2300KV Motor &Simonk 12A ESC For 250mm QAV250 FPV QuadCopter Mulit
CC3D Openpilot w/case Flight Controller 32 Bits Processor FPV QAV 250 400
T Plug Power Distribution Board/ESC for RC Quadcopter APM PX4 New
Hot Flysky FS-T6 2.4GHz 6CH Mode 2 Transmitter W/Receiver R6-B for RC Multirotor
2 Pairs 1045 Propeller 1045R 10×4.5 CW/CCW for Quadcopter Multirotor

what else do i need???

Thank you

21st July 2015 - 10:34 am

use 5 or 6 inch propellers for that motor.
3S 1300mah lipo should be good for beginners.

19th August 2015 - 3:10 pm

Hi Oscar, I have a UDI U818a quad that came with a stock battery which capacity is 500 mAh, but that didn’t provide much flight time. So I watched a video on YouTube where guy used a 1200 mAh battery instead of 500 mAh and managed to fly it almost double the time. I bought a 2000 mAh battery with the same voltage as a stock battery (3.7 V), and it’s a bit bigger in width and weighs two times (30g approx.) but that doesn’t quite matter. Recharged it with the stock charger that came in the box until the red LED turned green which means it’s fully charged. Then made sure the transmitter batteries were fully charged which are still brand new and not very used. When I turned it on and after gradually rising the throttle up to about 65% to lift it off the ground it did’t even lifted and it just shut itself down. I soldered a little power switch via one wire leading to the battery connector so I don’t have to unplug and remove the battery in order to turn it off. I turned it on again and did the same thing several times it did’t lift off the ground. I don’t know for sure should’t I left it charging a bit longer regardless of the green light or does it have to do with a tipe of charger itself. Any suggestion? Regards!

13th July 2015 - 6:44 pm

You mention in your article that you stop when the alarm says 3.5v … I always heard that discharging past 3.8v was bad… ? Any input? Thanks!

14th July 2015 - 11:11 am

3.5V is fine.

26th June 2015 - 11:55 pm

hi Oscar I’m making a quadcopter that weights about 1300g without the battery. I’m using HobbyFans 30A ESC, 2212 920kv motors with 9443 props, and a kk2.15 flight controller. what battery would you recommend I start with?

1st July 2015 - 1:28 am

i would probably look into 4S 3000mah to 5000mah for that size :)

13th July 2015 - 5:08 pm

Hi Oscar

I’ve exactly the setup you ask about, and 3S 5500 is to heavy (fly only 3 minutes and probably the ESCs get hot). I’ve found that the 3300 mah is very good. Flight time is about 10 minutes, and then low-batt warning initiate return to home. I’ve set the redundant battery capacity for 2 more minutes, so you will have about 12 minutes with a 3300. Probably 4000 – 4500 will be a good choice to, but the 5500 (470 grams) is to heavy.

23rd June 2015 - 2:44 pm

Hi,

I have Sunnysky 2212 980KV mortors, but nothing else with 25A ESC’s. My motor spec says Max continues current is 15A/30S. Recommendation is like 2200mAh 4s battery. I would prefer bit running time. How do i find the best possible battery?

When I calculating the max current, what C rating value we get in to consideration? Burst current or constant? Please help me.

cheers

23rd June 2015 - 4:36 pm

From the information you have at the moment, you can only decide on the C rating, and roughly the capacity range you should go for.
C rating depends on your total max current draw, and that can be determined from your motor / props combination you are going to use. you have not specify what props you want to use in your question.

1st May 2015 - 6:17 pm

Interesting read. You didn’t state what battery you would choose and why at the end. I’m curious to see what you picked based on the data. Also, I’m not sure I follow your statement on mah/s VS Load as the weight of the 6000mah battery isn’t in that range. Also, you lost me on the Flight Time VS Load graph and how that correclates to the 6000mah batter you were basing some of your numbers on. I see on the Flight Time VS Bat Capacity that the flight time starts to level off based on the battery size. I assume this is because of the weight of the battery and thus anything larger than the 6000 mah would be useless as you would see no increase in flight times.

6th May 2015 - 10:00 am

i went for 2200mah in the end :) cheaper, and more efficient. I wasn’t looking for super long flight time anyway :)

28th April 2015 - 3:43 pm

Thank you so much for all of the help that you have been providing. Here is my rig so far:
Lynxmotion Quadrino Nano Flight Controller- .64kg
Motor/ESC/Prop Combo- EMAX Quadcopter 550mm combo- 810kv/ 950g thrust per/1045prop/20A continuous 25A burst ECS/ 440g or .44kg weight for all 4 Rated for either 2S or 3S battery. I believe I want to get a battery that can push 100A or 25Ax4.

I am looking as 3s batteries in the range of 5000-5500mAh for longer flight time. What is the recommended battery for this rig? Will the flight controller limit the battery discharge so I do not burn out my ESCs? For example a 5000mAh 20C will give me my 100A. Should I still look for a higher C rating? I have created some Excel charts as above and the results are very interesting indeed.
I am trying to make this rig a stable platform with which to shoot video with a GoPro/gimbal which I believe is another 370g or .37kg.
I believe that my weight is at just below 2kg before the battery. Feel free to tear apart any of my calculations.
Battery
Battery Charger/balancer
Transmitter
Thank you

2nd April 2015 - 8:34 am

Hi Oscar

I hope you don’t mind this long post, but I think you might enjoy helping me :)

I am prototyping an Octocopter and I have a great flying beast weighing in at 40lb with a 10lb payload. It is designed and has the thrust to lift 90lbs.

Normal payloads are between 8lb – 15lb for this unit and it is designed to take a real punishment.

The problem, as you may guess, is keeping it in the air.

I am using a variety of test Lipos ranging from 6S 6000mAh 50C to 6S 15000mAh 30C. These batteries came from China and I don’t trust that they were rated accurately, but the weight and size match the basic specs for Lipos in their perspective categories.

My lipo combinations are: 4X6000mAh – 6X6000mAh – 2X15000mAh – 2X15000mAh Plus 4X6000mAh.

At full throttle each motor can consume approximately 52 amps at 1150 watts at 8 motors that’s 416 amps at a whopping 9200 watts. That’s a lot for an RC aircraft spanning 1400mm.

The motors I’m using are very efficient compared to the market leaders, but give me the power I can’t get from T-Motors or Avroto motors.

The actual problem is that I can’t get all of the mAh out of the Lipos. Hovering with a n 11.5lb payload is at 60% throttle and consumes 19amps per motor. No heat at all and everything functions fine. Without the payload the Octo weights in at 28lb and it hovers at between 40% and 55% throttle consuming about 14 amps.

I can’t tell you the exact amperage because I am only getting the peak amps at the end of the flight, I have to design a better solution so that I can get real-time data, but I’m also using my motor bench test data here to give a good approximation.

During the flight, with or without the payload, I start out at 25V and over the course of the flight the voltage drops off in a nice gentle curve, no erratic behavior. I land when my transmitter telemetry shows 21.3V. As soon as I power off the motors the voltage goes back up to 22.5 volts and within a minute the voltage is at more than 23V.

I am getting very short flight times. I should be getting at least 16 minutes but I’m getting 9 min. to 11 min. without the payload and only 4 minutes with the payload.

When charging the mA put back into the 15000mAh rated Lipos is only 7000. The 6000mAh lipos only take about 4000.

I believe that I could fly longer if I landed after the Lipos reached 21.3 (or even push that a bit) and waited 3 min. – 6 min. Although I haven’t run that test yet, I feel I could get more flight time and maybe drain some more useful current from the Lipos.

Somehow the Octo seems to be draining the Lipos faster than they can keep up, but once the demand is reduced, the lipos spring back fairly quickly.

I am no expert, but I know there has to be an explanation for what I’m experiencing… I just don’t know what it is…

Can anyone shed some light on this for me?

I much appreciate any constructive feedback you can offer!!

12th April 2015 - 11:51 am

Hi Anthony,

I’m no expert, but I think that those symptoms MAY be cause by the batteries being overdrawn. Maybe their discharge rating was falsely advertised and is not high enough to keep up with how much power you’re drawing. That would explain the voltage sag which recovers when landed, and would also explain the suddenly much shorter flight times when adding a little more weight (which increases current draw from the batteries). Just an idea anyway.

16th March 2015 - 4:50 pm

hi oscar
i am newbie to quadrotors i have already purchased kk 2.1 board. And i am looking to buy a 450 mm frame to make my first quad, but i want to make a 550 mm quad too and i want to add a cam on it too, my flight time requirements are of 10- 15 minutes, can you help me to select the proper combinations of motors, props ,esc and battery so that i can achieve desired results.And i can use them in both 450 mm and 550 mm quad.
thank you

20th March 2015 - 2:34 pm

5th March 2015 - 9:19 pm

26th February 2015 - 12:34 am

Hi Oscar,
Currently I am working on my school project and I need to make similar research. I have built quadcopter with total weight 2200g (including battery 500g, gimbal and FPV). Battery: 5000mAh 25C Zippy Flightmax 4s, motors: AX-2810Q-750KV, props: 11×4.7. I also use an eCalc for initial calculation of my setup, but I would like to understand all the mathematical relations on the background in this field.
Could you share with me an excel file or if you have some useful documentation ?
Thank you.

25th February 2015 - 6:14 pm

Hi Oscar, Thank you for the information. I’m brand new to building quad copters and really want to build one that will get off the ground. :) Anyway here is the materials I have so far: 500mm X-Mode Alien Frame (355g) , Board kk2.1 (33g) , Motor x4 2212 1400KV (188g) , ESC 30A x4 (100g) , Receiver (13g) , Prop’s x4 1045 (11g) Total Weight is 700g without the Battery. The motors call for ether a 2s 3s 2200mah battery. I’m not sure if this is per motor or if it is no matter how many motors I use? It just seems like a 2s 3s is far to small to fly this quad for very long. I don’t want to waist any time or money on buying the wrong batteries. Can you give me any ideas on what I should buy or if you think I have put together the right configurations of parts so far? I also plan on adding other stuff later on in the build. I want to add a FPV set up and GPS but right now I figured I would start off here. Thank you for any help you can give me. Mike Rodgers

26th February 2015 - 12:24 pm

Hi Mike
Battery cell count can be determine by the motor you use.
are you using Sunnysky 2212 1400kv? in that case you will be better off with 3S lipo.
Capacity wise, 2200mah to 3600mah should be a good range for your build.
You might also want to use smaller props for this motor. 8040 has the best efficiency, but 9 inch props gives you more thrust. 10 inch is probably too big and inefficient.

10th March 2015 - 11:46 pm

I’m not sure if you received my last reply, I wanted to thank you for your input. I finished my build and now i will be ordering the battery and 8 inch props. I’m glad you gave my the information about the props. I will let you know as soon as I get it off the ground. I hope the fact that I was off on the weight about 100g won’t make to much of a difference? I didn’t know that the scale that I used was off by a good bit and the total weight is just over 800g. I will try the larger mah and try other size props as well just to see what works best. Thank you again

15th March 2015 - 6:29 pm

That’s great Mike! :D
Love to hear your experience :D

19th February 2015 - 6:46 am

Hi, Oscar, I was getting an average of 18 minutes flying time on my tarot t960 hexa with 2 5400mah tiger lipos In parallel. So thats 10800mah. Is that long enough or should I be getting more? My motors are tarot 5008, 340kv with 1755 props. One more thing, a while ago I flew my hexacopter but the naza low voltage warning appeared after only 6mins on fully charged batteries. When I checked, the other battery wasn’t discharged. There is nothing wrong with my parallel connectors so can you think of anything that might be the cause of only one battery discharging despite the fact that they’re both brand-new and fully charged before the flight?

19th February 2015 - 10:16 am

what’s your AUW ? What is the C rating of that battery you are using?
Have you not got a voltage OSD? so you can check the actual voltage when the buzzer goes off and verify.

17th February 2015 - 1:14 am

Hello,

i want to build quadcopter with this parts:

motors – rctigermotor.com/html/2015/Navigator_0206/286.html
esc – rctigermotor.com/html/2013/esc_0916/85.html
fc – xaircraft.com/products/superx/

that quad must have Gopro and video sistem. That is about 3 kg all together.
what battery should i use for that? What voltage, what capacity…?
All the best!

17th February 2015 - 9:25 am

looking at the thrust data provided by the seller. 3KG of weight, that’s about 750g of weight need to be handle by each motor. Taking into account the efficiency lost, I would make it 900g. Assume you are using 17inch prop, you should be able to hover at less than 40% of throttle, current draw should be less than 5A for hovering. assume half of the time you are using 75% thottle to fly around, and the rest of the time hovering, average current draw would be about 12A. (This is purely estimation).

The data is rated at 24V, which is a 6S LiPo battery voltage. For 20 mins of flight time, you will need about 6000mah, but of course the bigger battery you get, the heavier it gets as well, so you need to adjust your quadcopter’s weight in the calculation above.

So a 6S 6000mah would be a good starting point? if you can reduce the weight, you should be able to get 20mins of flight time with 5000mah according to this estimation.

15th February 2015 - 3:36 pm

Hi I’m a beginner in making this quadcopter. So need some help… I m using EMAX CF2822 1200KV
And total weight would be around 1.7kg. So what ESC and what battery should I use? I need to perform acrobatics. And how many such batteries should I use

16th February 2015 - 5:08 pm

Well, i can’t find any data regarding this motor, and I have not personally used it, so I can’t recommend a setup for you.
maybe check with the seller where you buy it from.

4th March 2014 - 3:12 am

assumptions are good but at some point battery weight will be too much and your multicopter will not liftoff even if your calculations will predict 20 minutes of flight time with huge battery, so you should accommodate for maximum battery weight.
As rule or thumb we always set maximum payload of multicopter so it can lift itself at 45% – 50% of throttle.

another problem is with battery performance you set that 25c – 50c batteries are ok . From experience I can tell that cells in each batteries are not equal and some discharge quicker and some discharge slower, for light multicopters you can get away with small C battery rating but for heavier hexa or octo copters you need 65C – 135C or pair of batteries connected in parallel to minimize discharge impact on each cell.

4th March 2014 - 9:11 am

Thanks for the input! :-D
About batteries that are too heavy to lift, that’s why I conducted a series of load tests first, to find out what the max weight it can lift (well, I would consider 80-85% throttle Max, so still have room when voltage drops), then select batteries that weights below that.