HI,

I have some doubtsI have a question, I'm about to switch from 4s to 6s, simply to experiment with the differences. I understand why the use of 6s has become the standard, but I already have very good power and agility with 4s using a 2207 motor of 2400kv in a drone with a standard weight of 700g, and I haven't felt the need to make the change. However, it seems that the time has come to try it out. If I calculate with the battery I currently use, it would be 16.8v, resulting in 40,320 rpm at maximum throttle, which I understand is the maximum speed at which the motor wants to spin without considering other factors.

It's known that for 6s, motors between 1700kv and 1900kv should be used, and listening to more knowledgeable people in the field like Chris Rosser, I understand that if I want to use my drone for freestyle to avoid turbulence and poor performance, I should use props with a low angle of attack like 5043, 5040, or 5031, and to compensate for the lack of power, use motors with higher kv, which I imagine would be 1900kv or even 2000kv. I'm not sure if this combination of kv and props will give me good results in smooth flight.

I know that my batteries can supply the maximum amperage required by most motors to consider. For example, the 2207 eco II generates a peak current of 38A * 4 with 505.5 props, which would be 152A for all 4 motors, and my 1.3Ah battery with 120c gives me a maximum current draw of 156A.

So, my question is, what benefits would lower kv motors like 1700kv offer compared to higher ones, or if it's worth staying in a middle point like 1800 or 1855kv. I've also heard that people recommend using 2400kv motors and limiting the throttle to compensate for the high RPMs of this combination, but I've also heard that this has a probability of burning my ESC.

In the end, with so much information, I don't know which combination would be best for me between props and kv. I must say that the flying style I like is a combination of aggressiveness and smoothness in flight, so I imagine that what would suit me would be a setup that has control and good response at medium and low throttle, and also at high throttle. What do you think?

There are a lot of videos on this.. and yes, I have done it.. just make sure your components (camera, vtx, rx, ect) can accept the voltage if they are not on a BEC.
Was there a performance difference.. yes, is it worth the “hype”.. that’s up to you..
I eventually killed that esc, mostly from the crashes.. it was fun being able to install either a 4 or 6s lipo and have the rig handle it accordingly..
Now I just built a dedicated 6s 5” basher.. the trick .. constantly look for 6s lipos ON SALE…
Don’t overthink it.. build it, fly it, change what u don’t like… crash it, fix it, don’t overthink it

Yeah 6S packs are super expensive. I will probably start buying them soon for a first build I'm doing.

(23-Apr-2024, 07:33 PM)Pathfinder075 Wrote: Yeah 6S packs are super expensive.  I will probably start buying them soon for a first build I'm doing.

I like the Ovonic brand. Long ago, there was a rumor that 'Tattos' manufactures these LiPos and they are just a rebrand. I don't know if that is true, but they seem to be good batteries. I got a bundle of 2 pieces, 1300mAh, 130C, weighing 195g for 52 bucks. If you calculate the specific energy density, I got 148 Wh/kg.

Where I'm facing a dilemma is in deciding which kv to use between 1700 and 2000kv because I'm unsure of the effect it would have on the flight if I opt for lower kv compared to higher kv. The motors are the only change I need to make since my FC and ESC support the voltage of 6s, and likewise does the VTX. Additionally, I'm considering taking advantage of the motor change to use them in another old build that requires new motors.

If you are very used to 4s settups, dont expevt to much from 6s.

The common 6s quads today are way more heavy and does carry more energy, they are very different in many ways.
If you like to explore the plus omph and not a slower less responsive quad with long flighttime - you need to go another way than chris rosser.!
1000mah 6s is the same energy like 1500mah 4s, if you see the true difference between 6s and 4s, you will need to choose the same amount of energy.

You wrote good thoughts about kv, any higher rpms than 40000 wont happen ....

The main thing is current, its the limit, lower current does allow other use.
As a performance loving pilot, i doesnt see too much reason for myself to use 1400mah 6s batteries.
My use is for a bit more precision on the edge of battery performance.
If used to 4s battery sag, they can be flown well, they have power its just a bit more variation.

My suggestion would be a small 6s battery, 1000mah - 1100mah.
The kv does also matter for acceleration, lower kv will be more friendly but less responsive.
Paired with high or low pitched rotors, it can be plastered.
You cant go wrong by choose between 1750kv and 1950kv, its high kv and there is insane speed on the right prop pitch.
Rotor choice will chance more than 100kv more or less.

More than 2000kv for 6s is plastering the weight of a heavy battery in my eyes, it does deatroy the benefits i like by use 6s.

So if it was me, I would look at what other people build and run. If you are going freestyle, most people run 2207 at around 1900kv. Same thing for props, look on YT, what is JB or Steele running. Buy a set of parts and build something. Fly it, tune it, test it, rinse repeat. Battery wise for me i'm looking no more than 850mAh and ideally 650mAh. I want to keep it light and 3-4 mins of flight time is enough for me, per pack. If you want to fly for 6-8 mins then you will need more, but you will end up with something that handles like a house brick. You need to work out the sweet spot. So for me I would grab 3-4 different size lipos and test them. Say 650, 850, 1000, 1200 and go fly each one and see what suits me best. Approach it scientifically.

Gradually over 3-4 builds you should get a handle on what you like and don't like.

As to Tattu Lipos, they are my favourite packs. I think Tattu is a rebrand of GensAce. IMO, you get more flight time from Tattu pack, but you pay more for them than GNB or CNHL. So i tend to run a mixture of CNHL and Tattu packs when i fly. CNHL are cheap and overall you get more flight time, but they don't deliver power as well as Tattu packs. But I can generally buy two CNHL Lipos for the same price as one Tattu of roughly the same size. So if you fly in a way that is very hard on the throttle, CNHL is not going to work well for you, it's more of a light acro and cruising/fun flying type of Lipo (at least the ones I have are). If you need superior power delivery and minimal sag then Tattu is where it's at. I tend to fly CNHL first when I fly, so maybe on an average session I might fly say ten CNHL packs back to back, then I fly the five or six Tattu packs I have (for that size).

Thank you all for responding.

Although I've been inactive for a little over a year, I'm used to flying 4S, and my flight time is 3-4 minutes with a 1550mAh battery flying aggressively with 4.5 pitch propellers, and it has very good power. Moving to 6S and with high KV, I'm going to do what I always do, which is to buy propellers ranging from 3.7 to 4.5 and see which one is better for me. I assume that with the extra power, a pitch of 4 will give me the power-to-flight time ratio I'm looking for. My drone with a GoPro Session weighs approximately 690g, and for me, it feels very good. Since tuning a 5-inch isn't so difficult, the PIDs are perfectly tuned, and since the build is quite solid, I could decrease the filters significantly. I was really surprised by how good it feels in the air it has almost no propwash and no bounceback. It feels very good overall, but this is with Betaflight 4.3.
When I change motors, I plan to switch to Betaflight 4.5 and retune the PIDs, filters, and  feedfoward which I don't mind at all. It's a process I enjoy.

 I'll probably put a 2207 motor on it. Maybe I'll opt for higher KV like 1900, since the Sessions are no longer in production, and I'm going to use a DJI Osmo 3, which will add a bit more weight. Combined with a 6S battery, I estimate the drone will weigh around 760g, but at 6S, I'm not worried about being at this weight for freestyle. I like the inertia and momentum that a heavy drone provides. What I don't like is having a camera as exposed as most action cameras. The Sessions were quite protected from impacts. The one that is most similar is the DJI Action 2, but I honestly don't like it at all, but this is already a personal preference in action cameras. Everyone chooses the one that has the most attributes that suit their needs. There's no perfect action camera for everyone, and in case I want to simulate a 1700kv motor, I imagine that limiting the throttle would work, allowing me to compare with different propellers and different KV.


Here's a flight pack I recorded right after finishing tuning the quad. Perhaps a more discerning eye might catch something, but if I achieve the same result when I switch to Betaflight 4.5 with a bit more thrust and without the corresponding battery sag that represents using 4S, I'll be more than happy.

Throttle limit wont limit the motors to reach 100% value.
You will ned to set a "motor output limit" to limit the max rpms, simulate 1700kv.

https://youtu.be/_VU1phPqoDk?si=dsa2NUMq4NzSO30a
More info if ur interested

(25-Apr-2024, 04:57 PM)hugnosed_bat Wrote: Throttle limit wont limit the motors to reach 100% value.
You will ned to set a "motor output limit" to limit the max rpms, simulate 1700kv.

 Ah, gotcha! So, using throttle limit won't cap the motors at 100%. Instead, I'll need to set a "motor output limit" to control the maximum RPMs right.