BetaFPV 1S F4 V2.x Review
• Chris
The BetaFPV 1S F4 V2.0 is an AIO flight-controller for all 1S aficionados. On paper it seems that I found my perfect flight controller for 1S builds: integrated RX, super light weight and comes with BT2.0 battery connector.
But does it live up to my expectations? Let’s find out!
DISCLAMER: This flight controller comes in at least three different versions - I ordered so early that I initially got version 2.0 - this version does not have a 5V BEC and you have to make sure that your VTX and cam can be powered directly from the battery. Version 2.1 comes with a 5V BEC, so no worries there. Also the earlier FrSky versions came with the slow MCU for the ESC’s - so no JESC and thus no RPM filtering on those. The versions currently being shipped by BetaFPV all come with 5V BEC and the BB21 MCU’s.
This AIO flight-controller super light weight - it weighs in at just 2.69g without the battery lead.
You can even get that weight down to 2.4g if you de-solder the motor plugs and solder your motor wires directly.
The flight controller includes a D16 capable SPI FrSky receiver, but there is also a DSMX, Futaba and no RX version. You also get an OSD and a spare UART for SmartAudio. The ESC’s are capable of pushing 5A continuous and 6A peak.
Thanks to the BB21 ESC MCU’s it is possible to install JESC and thus enable RPM filtering on this board.
In the package you will also receive a BT2.0 connector with pigtail (already soldered to the flight-controller), rubber grommets and screws for mounting the flight-controller.
Before shipping the flight-controller with BetaFPV’s own battery connector they shipped it with a solid pin PH2.0 connector. Unfortunately the PH2.0 connector is not a genuine one manufactured by JST. It is rather a thin PCB with pins soldered to it and a plastic cover on top. This plastic cover is pretty loose and it kept sticking to my batteries. After around 20 packs I got a loose connection, so I decided to swap to a genuine JST PH2.0 solid pin connector - no issue since then.
If you prefer the PH2.0 connector, I would recommend getting a genuine JST one with solid pins and just swapping it for the BT2.0 connector. I am sure there will soon be a better battery selection with BetaFPV’s new BT2.0 connector, but right now you can only get BetaFPV batteries with this connector pre-installed, which are - to be honest - not the best.
The pads for connecting your cam and VTX are pretty tiny, but they are placed on the outside of the PCB and are thus relatively easily accessible - still this might not be the right board if you don’t have a lot soldering experience.
Betaflight
I was pretty surprised to see the flight-controller shipped with Betaflight version 3.5.7. After dumping the settings just to be on the save side I installed a more up to date version: 4.1.1. Unfortunately I was not able to get a decent tune with 4.1.1 - During flight it seemed like the ESC’s were de-syncing for the fraction of a second. No matter what I did, I could not get rid of that behavior. With DSHOT600 and an 8k/8k loop I was not able to fly at all - 2 of the motors would stop spinning after a couple of seconds. I reverted back to 3.5.7 and had none of those issues. Maybe this is also just a problem of my 2.0 version - I am really curious if any one else experiences these issues.
All of this seems to be fixed with the latest revision of the board with the BB21 MCU’s - no issues running Betaflight 4.1.1 with RPM filters.
Conclusion
If you are going for a light-weight 65mm build, I can highly recommend this flight controller. If you are careful with picking your parts it is now easily (without any hardcore modifications) possible to build a 1S brushless whoop that weighs just under 20g without a battery.
The possibility of running RPM filters is a massive plus, especially in this size.
When buing the flight-controller from a different source than BetaFPV, make sure you are getting the version with BB21 MCU’s - especially when buying the FrSky version - all other version should come with the better MCU anyways.
The shape of the flight-controller is borrowed from the AlienWhoop brushed board and allows to save quite a significant amount of PCB and thus weight.
Seeing this board layout I wonder how much more space can be saved, keeping the same feature set - maybe BetaFPV managed to reach the limit here?
The price of $ 39.99 is in my opinion pretty fair for what you are getting and you can buy it directly from the BetaFPV website
Maybe next time?
What I would really like to see is a version without pre-soldered motor plugs and power cable, but they are pretty accessible so you can de-solder them easily yourself. Other than that, I have not really any complaints.
Chris is a Vienna based software developer. In his spare time he enjoys reviewing tech gear, ripping quads of all sizes and making stuff.
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