(19-Feb-2024, 10:42 AM)hugnosed_bat Wrote: more voltage range for the same capacity is a downside about handling and tuning.
i would like a cell which provides capacitiy between lower voltage range, that would give us benefits. better quality cells is what i aim.
hv is just 0.15v tuning on 1s for maybe 5second of the whole flight, elswhere is no benefit when it comes to hv cells in my eyes. i am waiting for better and smaller batteries on 1s, hopfully hv trend on 1 does stop when better quality will come.

betaflight will be in trouble reading 3different voltage and translate in to cellvoltage xD it would result in wrong voltage readout per cell, lots of possible trouble.

Hi Bat,

Back when I was flying mostly 1S "tiny" quads (some whooped and some not),
I didn't really notice the difference between a 4.2 charge and a 4.35 charge.
That said, I just charged the battery for the type; standard or HV. I also agree
that it just doesn't seem to make much difference on a 1S craft.

As you know, I am an endurance pilot and don't fly stunts; so far I haven't 
felt the need to adjust the tune on 99 percent of my fleet; they all fly good
just the way they are. I guess an easy cruiser flight isn't that particular about
the tune. 

In Betaflight, I generally set my battery Maximum Cell Voltage at 4.35 or 4.4
and the Minimum at 2.5 to 2.8. I sort of put the values to the limit on both
sides. Yeah, I don't change it for different batteries. While it may not always
be "spot on accurate", it is close enough for me. I never seemed to have any
problem with it. In fact, I sort of like how it all works out. The only place that
I can see any inaccuracy is at the end. At the end of the fight, if the OSD is
showing 3.0 volts per cell, the actual measurement is 3.4 or 3.5, so I am not
sure that this is a bad thing. Is it? 

I suppose that I would look at it differently if I was a stunt pilot and always 
pressing the quad and the battery. So, tell me, how does a stunt pilot look
at it?

Later, iFly  

Interesting times. Thank You for pointing out the new 4.4V chemistry on the horizon.
My newest quad is a Happymodel Moblite7 V3 Walksnail edition which I have been flying on 1s HV LiPo's, it came with an A30 plug. I was seeing a flashing red "skull" image in the OSD for the entire flight. After a few flights I connected to Betaflight and changed the default maximum battery voltage to 4.4V and the warning went away. Was that skull Happymodel's way to warn me that the voltage was too high? Or just a Betaflight setting that was not correctly set from the factory? After reading your post I looked at the Happymodel spec sheet:
For the quad: "Compatible with 1S Lipo battery or LiHv battery"
For the FC: "...1-2S Lipo LiHv battery input (DC 2.8V-8.7V), only support 1s input for this drone."
For the ESC: 1-2S LiPo/LiPo HV
For the motors: "No. of Cells (LiPo) 1S only" no mention of HV...
So Happymodel does a pretty good job of letting us know the limitations of this ready to fly quad but it is all a bit cut and paste. Someone who sorts through the component specs (motor limit) or heeds the default BF setup skull warning will conclude that we can only run a standard 4.2V Lipo with this quad. But we all know it is safe with a 4.35 LiHv battery. Having to go into BF to remove the skull warning certainly puts the ball in the users court
But not everyone is "intoFPV" savvy so there will no doubt be some fires, maybe even inside homes, when these drop. A different plug type is a nice idea but probably would not stop this, there is too much precedent for using plugs without regard to battery type. I agree that it's a potential safety concern!

@iFly4rotors may I suggest you watch a YT video, something like Nick Burns flying a Mobula6 in his home would be good. He's entertaining and a great pilot who will definitely show you the voltage swings aggressive racers and stunt pilots inflict on their batteries.
It was mentioned above but the Walksnail system is now my limiting low voltage factor when flying my 1S quads and whoops (that have that system).

Hi Husafreak,

Quote:Thank You for pointing out the new 4.4V chemistry on the horizon.

Perhaps, I miscommunicated. I don't know of any chemistry changes
that would push the voltage for a single cell to 4.4 Volts. Sorry that
I did not word that clearly. 

Instead, I was referring to the Battery Maximum setting in Betaflight.
Since I use a lot of HV batteries that I charge to 4.35 volts, I will
adjust this setting to 4.35 or sometimes 4.4 which is still close. If this 
setting is set too low, Betaflight seems to think that you have one
more cell than you actually have. I really can't tell the difference 
between them in actually flying.

I initially set the Battery Minimum below 3.0 volts to prevent the
"Low Level" warning from coming on sooner than I want. After running
a lot of batteries through and determining the "drop dead" threshold,
then I adjust it up a little at a time until the warning comes on when I
have about 30 seconds left before the quad drops from the sky.  So,
when I see the warning, I know that I have less than 30 seconds to 
land which is normally plenty for me since landings are more of a
controlled crash. 

Although I still have many 1S tiny whoops that I fly indoors, I have 
moved to a 2S minimum for my builds due to the limitations of a 
4.20-4.35 volt power source which include a very short fly time and
this with analog. The more load one puts on that little battery, the
faster it draws down.  
 
Later, iFly  

(19-Feb-2024, 05:59 PM)husafreak Wrote: @iFly4rotors may I suggest you watch a YT video, something like Nick Burns flying a Mobula6 in his home would be good. He's entertaining and a great pilot who will definitely show you the voltage swings aggressive racers and stunt pilots inflict on their batteries.
It was mentioned above but the Walksnail system is now my limiting low voltage factor when flying my 1S quads and whoops (that have that system).

Hi Husafreak,

Yeah, I do watch Nick Burns videos, but I don't focus on them too much so I 
might miss something. The flight videos sometimes make me dizzy, so I sort of
gloss over the flying parts. Yes, I am aware of those voltage swings and sags. 
Those abrupt velocity changes also allow the motors to "back feed" the 
system. The hard ACRO stunt pilot has a lot more to contemplate than I do.

Later, iFly  

the most good 1s batteries are hv, even as i would like normal ones im forced to hv by the choices.

for bigger quads from performance perspective, more voltage range does decrease the ability to go on the edge of performance. more cells does match better than hv.
as example if we like to do speed, we need to adjust/choose the kv for a fully loaded hv battery, we like as much kv as possible (as much as the motors turn energy into thrust, befor the point where there is heat without additional thrust).
hv cell does need lowered kv but doesnt give higher voltage in truth for more than a few seconds.
a common lipo does give benefits about consisdency, it allows to choose higher kv, more optimized for more part of the lipo capacity.
another thing is reliability, hv packs are way worse in longterm use.
so for gaining one time a topspeed and trash the liponin one speedrun. a hv battery can give a higher topspeed than a common lipo, but as example for racing the inconsisdency over the whole capacity isnt usable. for consisdent performance a common lipo is ahead.

the dream for performance would be a pack which is full on 4.2 as example and empty on 4.1(doesnt give any energy than) on the same capacity. that would flat out the performance a lot and would allow new sort of precision.
battery performance is still the bottleneck.

much energy on a stable voltage.
when we compare the capacity size and weight, hv cells arent less heavy or has higher discharge rates; i dont see any other difference than voltage.
is there anything else changing than the voltage on a hv cell?

Hi Bat,

Thanks for the explanation. I do realize that I don't always know or understand 
things about Racing or ACRO stunt criteria; especially when it comes to batteries 
and such. I appreciate you taking the time to explain it to me.

Thanks.

Later, iFly   

i mistakenly wrote voltage readout but was thinking about cell count readout.

as example if we plugin an empty 6s lipo, betaflight does read it as 5s battery and shows wrong voltage per cell. the voltage readout is always right just the cell count not.

i does use volt per cell and did try ti fly an empty 6s pack by mistake.
i believe a thirt different voltage per cell would give wrong results between much more different cell counts.

3cells on 4.45v would give 13.35v fully charged, it might be displayed as empty 4s? it might give much more mistakes for displaying single cell voltage

Hi Bat,

Since most of my batteries are HV, I did start with 4.35 volts and then experimented
from there. I believe that I came to the conclusion that the 4.5 volts was too high,
but 4.4 volts worked about the same as 4.35 volts. The 4.4 volts allows for a battery
that has charged to an actual voltage of 4.37 (yeah, sometimes a battery will charge
slightly higher than 4.35 volts). You know, I would prefer that the OSD per cell 
voltage be on or slightly above the actual battery voltage so as not to prematurely
trigger the "Low Battery" warning. 

I use the minimum voltage to set the "Low Battery" warning. I like to have about
30 seconds to land (or get close to the ground) before the battery "dies". That
said, I also have a general idea how long I have just by the per cell voltage which
is currently the only voltage that I display on the OSD. Since I use batteries of
different cell counts (different total voltage), I just get confused by the total battery
voltage and trying to figure out how much that I have left. Since the low voltage
cutoff seems to be related to the per cell value, that is the value that I want to see.

Also, I am not concerned about how low the battery actually discharges, but rather
at what point that it will no longer power the quad. If I could drain them down to
an actual 3.0 or even 2.8 volts, then I would likely do that if it gave me more fly
time. When my goal is maximum fly time, that supersedes battery management. 

Yeah, I might be a bit eccentric, still, we each have our own path. 

Later, iFly  

to figure out how much spare energy is left and could be used for more flighttime: charge the battery (not in balance charge mode) and check the true charged capacity.

the best would be to know exactly how much capacity is in a pack by specs of the manufacturer, some arent very accurate.

i would focus the recharged mah more than the voltage to get all possible flighttime out of it.
voltage drop doesnt allow to use full capacity if the average current/discharge rate is to high. if battery performance matches well, it offers the use of mostly the true capacity.

my 1s packs does so high voltage drop, i can only use flighttime and drawn current, feel of performance as indicator for the used capacity. voltage doesnt give much info for me on 1s whoops, flown with much throttle.

For 1S, either LiPo or LiHV, I set my warning voltage to 3.2 and the minimum voltage to 3.1. At "low voltage" at 3.2 volts I have about 20 seconds to get 'er home before I have to land. Once it gets to the LAND NOW message at 3.1 volts, I have about 10 seconds before it falls out of the sky.

Then after landing and disarming, the voltage always climbs back up to 3.4 or 3.5 volts unloaded. I don't believe this harms the battery.

All of this sagging is much less with 2S and higher.