RC India

Hello guys....I have a quad in which the avg amp draw during hover is 30 amps...The lipo that I am using right now Is 2.2ah 25c 3s. Now what I was wondering was if I connect this battery in parallel with another 1.5ah 3s 30c will it work ? As the capacity and discharge of both batteries is different can I still connect them in parallel? Why I am asking this is because I have seen people connect 2 batteries with same capacities in parallel...
Regards

Also what will be the final output that I will be getting ? Will it be 3700 mAh 25c ? I will also test if the flight time of my quad increases with the 2 batteries as wieght will also significantly increase.
Regards

First i have doubts if the quad pulls 40Amps on Hover !!

Usually putting 2 different batteries in parallel is not recommended.

Okay sir.. I am using the a2212 1400 kv motors but there are no charts available which show the amp draw neither I have a wattmeter so I'm just guessing the amp draw ...

short answer no you cannot connect them if they are different capacities. one of them will empty out sooner and the start to puff, while the other one will be still be ready to perform. 30 A * 12.1 = 363 W, just like saurabh says,  i doubt you need that kind of energy to hover a quad powered by 2212 motors.

Ok sir. Actually the main problem is that the lipo gets hot after hover of about 7 mins. The total volatage is around 11.6 volts.Is that something to worry about ?
Regards

All lipos get warm after continous use (all the more pronounced with copters as the motors are always running), so is it HOT or is it warm. Can you clutch it in your hands for 20 seconds after the flight without feeling uncomfortable (be safe when you do that) ? If you overuse a lipo, it might get really hot. No i dont see a problem with 11.6 volts as voltage sags under load. Is the lipo taking full charge while charging or has the capacity reduced? Also the differential in the cell voltages after when discharged tells a lot about the state of the lipo. Would be good to know what the cell values are after it gets discharged.  The golden rule with lipos is to discharge them to about 30% of capacity, not more (which is around 11.4 v on no load).

Sir when I try to charge fully the first 2 cells stop at 4.18 volts while the 3rd one gets charged to 4.20 volts. After landing the voltage is 1st cell 3.85 2nd cell 3.85 3rd cell 3.87 volts.
Regards

Why guess (30amps) when data is available for a reasonable estimate?

Let me repeat what I said on 17th on your other thread:
Kanav, here’s one way of approaching the problem:
The first rule is to start from observation instead of from opinion.
Known facts:
1. Hover time 5 min 30 sec
2. Battery is 3s 2200mah
3. Since you had earlier asked about how low a lipo can be run, you probably did not use more than 1500mah

So let us assume that 1500mah was used in say 5 minutes, or in 1/12 hour.
Or 18,000 mah in one hour.
Ie, drawing 18 amps.


BTW, curious why do you need more hover time...

A few months ago, Balakrishna Reddy had started a thread on connecting different batteries...
Let me bump his thread to life again!

Yes sir, I will read that thread , more flight time because Everytime I fly it and take it a bit up the lipo gives up 4 mins approx  that is too less...just because of. That wanted to elongate the flight time sir.
Regards

Kanav,
The real solution for higher duration from a given battery is more efficient props and motors.
Since the motors and props cannot be changed (at the moment), that leaves the battery.
Which has a trade off between weight and capacity.

I had suggested in your other thread to check the hover time by adding a payload equal to your present battery weight.

I believe your quad weighs about 1000 gms with about 200 gms lipo, and does 5 minutes hover.
If the weight was doubled to 2000 gms with payload, the hover time would probably be halved to 2.5m
Pl check this.

If correct, it means you can add 5 lipos of 3s 2200mah weighing about 200gms each.
Each of which will contribute 2.5 minutes.
Hence a total hover duration of 15 minutes.

Incidentally,
Saw that you sought help for you first plane, and having flown which successfully, you put up the electronics for sale.
Then sought help for your quad, and having got it flying successfully, put up the electronics for sale.
Hence not clear what your plans are...

BTW, someone else on the forum is currently selling the same motors for much less...

Sir nothing is up for sale. I am thinking to change the whole propulsion system with efficient motors of 1000 kv with 1045 props so I am selling these ones.But till they are not sold will work out with these ones.
Regards

In past, I told you to use 1000kv motor with 1045 propeller but that time, you don't want to go for 1000kv.
Using 1400kv motor with 1045 propeller is not good.
On Aliexpress, you will get cheaper A2212 1000kv motor as well as 1045 propeller.
$3~$4.5 is good price for motor as compared to wholesale market of Delhi

Taksh I am using 1400 kv with 8045 and not 1045 propellers.
Regards

I know about your post of propeller for 1400kv motor.
You purchased 8045.

If you have temperature sensor and if you going to fly your quad then check temperature of lipo then tell me as i never saw lipo with high temperature.