BetaFPV Beta95X: switch to 48 kHz to gain autonomy


You already know the method of flashing the ESCs of a nano racer at 48 kHz to gain autonomy (see here et leaves). It is intended for ESCs running under BLheli_S firmware. But BetaFPV's Beta4X 1-in-95 ESC (see the test here) is a BLheli32. The method for switching to a frequency of 48 khz is not the same as with BLheli_S, it is… even easier to perform! You must first download the BLheliSuite32 tool (here), it is offered for Windows PC, Mac OS X and Linux. Launch the app. The good reflex is to remove the propellers or to secure the device so that it does not escape in the event of malfunction of the ESCs – disconnecting the battery in an emergency can be very complicated if the motors are running at full speed! Connect the Beta95X to your computer with the microUSB-USB cable, and power with a sufficiently charged battery.

How to proceed ?

In the drop-down menu Port:, choose the one that corresponds to the Beta95X – it is the same port used by Betaflight Configurator-, then click on Connect. Click on Read Setup. In the summary window, check that the 4 ESCs respond well. The box we are interested in is PWM Frequency. The value is 24 kHz by default. Drag the slider to push up to 48 kHz. To validate the change, click on Write Setup. Writing is very fast. Unplug everything, attach the propellers, and take off!

Gain ?

With a 4S 450 mAh battery from Tattu, indoors with a calm flight, I get 3 minutes 40 seconds of battery life with the factory Beta95X. Once the 48 kHz modification has been made, this autonomy increases to… 5 minutes and 30 seconds, i.e. a gain of approximately 30%. Not bad for a hack that only takes a few seconds! I noticed a slightly more flexible behavior, without any parasitic vibration.

What happiness?

In general, all the improvements have a collateral effect… Switching to 48 kHz can introduce a reduction in power at full throttle and parasitic variations in engine speed. For my part, I did not experience either of these problems, the Beta95X retained its original power. If you notice a problem with the power, know that you can return to 24 kHz at any time. You can also try to find the right compromise by a method of trial and error. The goal in this case is to find the intermediate value between 24 and 48 kHz which does not introduce a loss of power but which nevertheless allows to gain autonomy.

Thanks to groove4life for motivating me to give it a try!


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  1. I did it on my 75X via JazzMaverick and I gained a good big minute of autonomy with my tattu 2S 450mah. It really is a thing to do! no need to update its betaflight, just the esc to flash.

    In the end, this 95X is just crazy.. a big tiny whoop that lasts 5 min with HD feedback.. What a dream!

  2. @Fred: thank you very much for your tests and your feedback on this 95x, which seems positive in terms of autonomy, without introducing any unwanted inconveniences (and so much the better if I was able to tickle your curiosity a little at test this PWM increase at 48KHz).
    The more feedback we can read, the better we will understand the potential of these improvements.
    I did this mod 2 weeks ago on a Diatone 349SX, also enjoying switching to BTFL 4.1.1 and active RPMs. Everything works but the weather (wind and or rain) did not allow me to really test if there was a gain in autonomy. (The theory predicts that the more the size of the motors increases, the less there will be an impact on autonomy! We'll see…).
    When I made my mod I went from BlHeli_32 Rev 32.6 to Rev 32.7.
    On your tutorial I see that you are in Rev 32.6. Did you stay on rev 32.6, or did you upgrade to 32.7?

  3. @fargeaudoux: Yes that should work….
    Like you, I have a Beta85 Pro 2, having these characteristics according to BetaFpv:
    F4 2S AIO FC, 1-2S ESC with 5A continuous and peak 6A current, Support BLHeliSuite programmable, 1103 11000Kv motors.
    ESCs are not compatible with BlHeli_32, we must turn to BlHeli_S, and additional devs made available by JESC or JazzMAverick for certain ESCs, BlHeli_S not offering as standard nor the possibility of mounting the PWM at 48 or 96 KHz , nor telemetry if you want to activate RPM filters.
    I made the same mod (JESC) that Fred describes on December 30, 2019.
    One could also choose the JazzMAverick version that Fred describes on January 6, 2020, but when I did, the JazzMAverick still needed a bug fix, since done.
    So I flashed with JESC 2.2 and PWM=48KHz, and haven't activated the RPM filters yet, because I didn't want to modify the parameters too much in order to have a small chance of knowing which mod brings which effects.
    Everything works well, except that I am not really able to certify an increase in autonomy, to my great despair!
    But this may simply be related to the fact that I only have 4 miserable Lipo 2S (2x BetaFpv 300mAh, 45/90C and 2x CNHL 450mAh 70C, much heavier) which are very tired and which do not have the reputation for being the best. Suddenly the sag is important and if I want to compare by stopping at 3.5V for example, I just have to disarm so that the voltage rises instantly to 3.8V, and I can fly again for a short time, and this several times in a row, which probably prohibits any valid comparison.
    Fargeaudoux, if you are fashionable I would be interested in knowing your conclusions, and incidentally which lipos do you recommend?

  4. @fargeaudoux: concerning the Beta85 Pro 2 (sorry I'm going a bit off topic, but for cheap it's worth it…).
    Personally I found the original camera of the 85 Pro 2 archi rotten, especially after seeing the RunCam Nano 3 of the Modula6, and I ordered the C01 Pro FPV Micro Camera $14.99 USD, postage included at that time and without taxes seen the low price. It arrives in a nice little box, with a white canopy, much more resistant than the original one of the 85 pro (not difficult…) and an ad hoc camera support, which makes it possible to do without the original foam camera support .
    In my eyes the difference is stunning and is more than worth it.
    Having also received the RunCam Nano3, (bigger than the C01, but a bit lighter and a little more expensive) I find them quite comparable, with perhaps an advantage over the RunCam nano3, (to be confirmed once installed in my 2nd Beta85 pro for which I would also replace the Vtx with the more powerful Nano Vtx Eachine), for which it will be necessary to tweak the BetaFpv support of the 85, because it is larger than the original one as well.
    And since I like having telemetry to find those whoops more easily in shrubs or grass, they are under CRSF Nano se.
    Well I had fun... because I find them much more fun to fly in the garden or in a park than my Mobula7 from last year which, for my taste, went into failsafe far too early and held up less well in the wind.

  5. Hi Hi! thank you for this tips! I have a 95x v3 with the new motors/propellers, and when I wanted to test, on behli32 I have two options, low pwm frequency and high, I hadn't seen udebut and therefore put it only on low without doing it on purpose … and the high on 24, more autonomy but still a bug sometimes I put it back as before, you have to put both in 48? or that high? or that low? Thank you in advance and Happy New Year!!!

  6. @ David DALBERA: Sorry my Beta95X died in excruciating pain, and I can't remember the settings 🙁 But I think you got answers on Facebook 😉
    Good flights! 🙂


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