Flight time/Lift up issue with 1S Battery under 4V (Mobula6 HD)

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ejlover

Member
Greetings,

I own a Mobula6 HD for about 2+ months. I have a set of (4 pieces) Happymodel 250mAh OEM 1S batteries and 6 pieces of Tattu 450mAh 1S batteries. Problem is:

- I begin my flight at full charge and battery voltage drops so quickly under 4Vs (about 30 seconds on 250mAh batteries and about 1 minutes in 450mAh batteries) during the flight.

- I have a very small apartment building so I'm not even flying so hard or fast.

- When this voltage drop happens my drone can hardly lift off from the ground even at full throttle.

- When I land, battery level increases over 4Vs. And I can lift of for a few more seconds but drone drops on ground level immediately.

- When I plug the batteries on the charger I'm seeing that they have 3.8-3.95Vs of charge (after about 1minute flight time on 250mAhs, and 1,5-2 min flight with 450mAhs-about half of this time is with full open throttle and hardly lifting drone)(that should be more than enough for flight, but drone hardly lifts off at full throttle).


Batteries had 30-40 charge cycles. I use happymodel (generic) 6-in-1 charger. And I charge 250mAh batteries at 0.2amps.

All settings on the drone are stock settings, stock body, and stock propellers; and I didn't make the 48kHZ mod. I fly in Horizon mode (air mode and antigravity turned off).

What may be the cause of the problem? Did batteries die?
:s
Or is it something related with drone hardware? o_O
Thanks for your time, I really appreciate your support
:thumbsup:
 
wafflejock

wafflejock

Well-Known Member
It's public now the forum just has some gates to stop from getting flooded with spam. Regarding the issue, a battery "dipping" below 4V when under "load" or when supplying current for motors go turn. The amount of dip you're saying isn't bad but the quad should be able to fly down to about 3.6V per cell before the thrust to weight is an issue. You may want to see if the quad is compatible with 2S batteries and use those since will have a lot higher top end then and won't be pulling as much current for the same watts of power pushing the props so less voltage dip too. It could be the case there's a relatively high resistance connector or connection from the battery to the quad so maybe worth redoing that with and xt30 or something but either higher voltage or using higher pitch props will give you more punch and increase the power to weight ratio.
 
E

ejlover

Member
wafflejock said:
It's public now the forum just has some gates to stop from getting flooded with spam. Regarding the issue, a battery "dipping" below 4V when under "load" or when supplying current for motors go turn. The amount of dip you're saying isn't bad but the quad should be able to fly down to about 3.6V per cell before the thrust to weight is an issue. You may want to see if the quad is compatible with 2S batteries and use those since will have a lot higher top end then and won't be pulling as much current for the same watts of power pushing the props so less voltage dip too. It could be the case there's a relatively high resistance connector or connection from the battery to the quad so maybe worth redoing that with and xt30 or something but either higher voltage or using higher pitch props will give you more punch and increase the power to weight ratio.
Click to expand...
Hey, thanks for the detailed explanations, much appreciated. Unfortunately, Mobula6 HD only supports 1S batteries :( From most videos I've watched people are flying without any issues even under 3.5V, but I'm having issues beginning at 3.8-3.9 range most of the times.
You are probably right, because PH2 connector is hot after every flight (motors are not even warm). That must be the issue :(

I have also bought a bigger (75mm) frame and larger props (40mm). Maybe it's time to switch to those.
Will I loose agility after switching to bigger frame/props? Since I flight tight indoor quick moves is a must for me.
Also modding JESC 48khz would increase flight time, but it causes loss of power which I worry to loose my ability for quick maneuvers in tight spaces.
 
wafflejock

wafflejock

Well-Known Member
I don't think you lose much agility at these sizes but the power can be too much for inside so you end up sort of losing throttle resolution because you'll never use the top end inside on say a 2S but I don't really know how much just increasing the frame and prop size will effect things by themselves as any of my ones bigger than tiny whoop are 2S and I typically fly them at small parks where a 5" is too big for the place but prefer just finding a big park and flying the 5" myself.
 
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Ianmcmill

New Member
I have the same "issues" with the Mobula6 HD. I think it's just too heavy because of the HD camera pcb.
Flight time with the stock 250mAh is really short. After 2-3 flips and loops the voltage is almost at around 3.0v.
My first drone was a Eachine Novice 2 with 2S. I think I was used to the longer flight times and now I'm a bit disappointed about the short flight time the Mobula6 HD has. But I guess HD video comes at a price on 65mm tinywhoops.

I ordered a 75mm frame and 40mm props. Nick burns made a video explaining how to upgrade the Mobula6 HD.
I also ordered some different batteries. 300mAh and 380mAh 1S GNBs with the connectors directly attached to the batteries.
Havn't received them yet. I also ordered a URAV 75mm carbon wheelbase. Sellers says it's only 1g. Let's see how that turns out. I think about cutting the guards from some spare 75mm frames and use them with the carbon wheelbase when flying indoors.

I'll post more once the parts are delivered.
 
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