[nacholibre]

I need some help understanding making the right battery choice for my unit to maximize my flight times. My concern is that im only averaging about 4 minutes. I know that im heavy because i have alot of (lets call it armor) foam on my unit to try and protect it until I am a better pilot. i have a clone black out qav250 with T2204-2300kv motors 12a esc's and i weight in at a whooping 434.9g without the fpv gear on. What should i expect from this set up? I am using 3s 11.1v @ 2200mah batteries and they charge to 3.35v per cell. Thats as high as my skyrc imax b6 charger will charge them.no matter what setting i charge them at(charge/balance or fast charge) i almost never choose fast charge setting. your input is valuable and i thank you in advance.

[nacholibre]

ok so i found out i need to keep resetting it and it will charge them to 4.2 per cell. For some reason it wont charge them up to that in one setting. maybe i have my thresholds set to low on the charger which is new to me but i do like it

[jbarchuk]

ok so i found out i need to keep resetting it and it will charge them to 4.2 per cell. For some reason it wont charge them up to that in one setting. maybe i have my thresholds set to low on the charger which is new to me but i do like it

I plugged your numbers into ecalc and the results look pretty average. I highlighted a couple of items of interest. I had to guess at a few things such as the exact motor, and prop size, but these should be close.

The expected flight times are in the bottom left corner. Flight time is a function of throttle. If you fly as a pure leadfoot you won't get even 4 minutes.

That 3.35V you mentioned is very scary. If that's how far -up- they charge, how far -down- do you usually run them? Leaning on a battery that hard very many times will drastically lower performance (power and time.)

[nacholibre]

thanks that helps alot. an im sorry i miss typed. it was suppose to be 3.85 and i have a alarm on it so i bring it downwhen the alarm stays on or it will shut off.i want to say at 3.5 mayb. it think somewhere close to nominal voltage as a total of the 3 cells. that doesnt seem like alot of time. is this what most pilot are averaging. or am i just too heavy? 4 minutes doesnt even seem like enough to break out the fpv gear because im sure its less when that extra weight is there and the extra draw. my fpv works off the balance plug. and the batteries arent even really that hot when im done. plus my charger was set at defaults so it wouldnt bring it up to spec. i changed the settings and its bring each cell to 4.20 total 12.60 i am about to go time test and se what i come up with. lights shouldnt matter because i use a separate battery for that. thanks again for the reply and the very useful info. I appreciate it.

[jbarchuk]

that doesnt seem like alot of time.

It depends on flying style. I fly flat out leadfoot and I don't WANNA fly more than 4 minutes because it's EXHAUSTING.

If your charger hasn't been working properly then you may see times doubled which would be in line with the 'mixed flying' time which is cool.

4 minutes doesnt even seem like enough to break out the fpv gear because im sure its less when that extra weight is there and the extra draw.

I added 2oz to the weight. It took 1 min off the mixed time and 0 off the leadfoot time (which doesn't seem to make sense but I don't know.)

[nacholibre]

It depends on flying style.
 well i guess im still a littles shy due to inexperience. I take it easy for the most part and only really get on it occasionally. but i feel like i could fly all day sometimes. but im sure thats just because im new to it. what is draining to me is all the working and trial and error programming. my down fail im sure is impatience. and that i have been a senior master ford fse for little more than 12 yrs now. and i guess that makes me think im a little smarter and capable than i am. and when i fail it really eats at me lol. but its been very humbling i assure you that. i go back to the marcelous wallace pulp fiction speech. " thats pride f****ing with you" lol but i like it and i got over that real quick. when i see how much some of these guys know im humbled and beside myself.everybody on here has been great and very helpful. i think its a great communitty. and i was hesitant at first to come to a forum. but i am glad i did and surely wouldnt be flying still if i wouldnt have. i appreicate your input and value it. thank you. i got to excited earlier and forgot to set my stop watch before i started but it was around 7minutes this time i think. im gonna do one more and call it a night my friend. and btw i am stopping at 3.77v i checked this time lol. sorry that i dont write that well. im more like a willaim faulkner. i like run on sentences and just write how i would probably talk lol. take care

[Highspeed1964]

So just to talk about the charger for a moment, I'm not very familiar with the imax b6 but if it's like my charger there is a time limit to how long it will let you charge before it does a safety shut-off.  I like to charge my batteries at about 2 - 3 C.  Since my larger flight batteries are the same as yours (3S, 2200mAh) a 2C (4400mA) charge is about the best I can do with a 5A power supply.  At this rate, I can charge the battery before the safety timer times out.  If I go 1C (2200mA) it will sometimes time out before it is fully charged.  Since you said you do not use fast charge I imagine you are running into the safety time out on the charger which is why you have to restart to get a full 4.2v/cell charge out of it.  Most chargers do let you adjust this timer, though.  See if you can find that in the settings on the charger.  Hopefully, that'll get you charged in one cycle.

Highspeed

[nacholibre]

yes thats what it was. it was several default safety settings. But i got all that straightened out lastnight and went out had a little longer better flight. hey when all else fails read the directions, right? i really appreciate the reply and info. i really like this charger. its pretty high ranking for its class. and it just smokes the little crappy one the sent me with the first batteries i bought. that junker took near 30+ hrs to charge one. And it ruined one as well. i really like these fast speedy little suckers but i want something where i can go out and explore for 30+minutes. seems like a man could spend a lot of money on this hobby.

[Highspeed1964]

Awesome!  Glad to hear when these things get sorted out.

Enjoy your flying.

Highspeed

[jackyoung]

Hello , For FPV 250mm, Only have 4mins flight times it is a little too short. In general, it can reach over 5 mins flight times. How to choose the longest battery? I know a formula for quadcopter flight time calculator is that Quadcopter flight times =(Battery Capacity * Battery Discharge /Average Amp Draw)*60. You should know Average Amp Draw of your quadcopter. But before it , what's your battery C-rating? battery c-racing is greater than target c-rating (quadcopter). In my opinion, I suggest you choose 4s rather than 3s, and select high C battery such as 75c or 95c above, it can provide your quadcopter enough energy.

[TheOtherCliff]

Really, the weight of the battery (which is proportional to watt-hours) is your direct factor for flight time.  A 4s750 has as much energy as a 3s1000 (since 4 x 750 = 3 x 1000) and weighs about the same and hovers about the same length of time in a correctly configured quad.  "Correctly configured" could mean different KV and will mean different props.  Since you probably already have motor KV selected, you must decide prop size and number of cells.  If you change the number of cells you should change the prop size to match.

Larger props turning more slowly are generally more efficient.  Two blade props are more efficient than 3 blade props.  You can't just go from (examples) a 2 blade 5x3 to a 3 blade 5x3 unless the "size" of the 3 blade is better than the 2 blade and in that case, you shouldn't have been running a 2 blade 5x3 in the first place. 

One final thing is that if you have your PIDs too high (especially the D terms), you could have invisible oscillation which reduces flight time and causes motors to heat up more.  A simple test is to reduce your PIDs (especially the D terms) and see if you get longer hover times.  Export settings before you do this in case you forget your old PIDs.