Whereas many FPV drone producers are busy copying one another and releasing near-identical merchandise lately, HGLRC is without doubt one of the only a few corporations nonetheless making an attempt to innovate and do one thing genuinely totally different. I’m genuinely impressed by what HGLRC has achieved with the Rekon35 V2, a 3.5-inch micro FPV drone purpose-built for long-range cruising. It’s clear that numerous thought went into this design. After flying it and tearing it down, I’ve gathered loads of ideas—each good and dangerous. Right here’s my hands-on evaluation.
Serious about flying lengthy vary? Listed below are some sensible ideas: https://oscarliang.com/long-range-fpv-flying-mini-quad/
The place to Purchase
You should buy the Rekon35 V2 from these distributors:
What’s Included
- 2 units of propellers (8 in whole)
- USB cable for charging
- screws for mounting the props
- screwdriver
- stickers
- handbook
Specs
- Body: Rekon35 V2
- Flight Controller: HGLRC H743 20A ELRS 2.4G 2S V1 AIO
- FC Firmware: HGLRCH743
- Gyro: ICM42688P
- Motors: Specter 1404 5500KV
- Digital camera/VTX:
- HD: DJI O4 Lite Air Unit
- Analog: HGLRC Zeus Nano VTX 350mW
- Receiver: Onboard ELRS 2.4G (or 915MHz)
- GPS: HGLRC M100 Mini
- Propellers: Gemfan 3630 triblade
- Supported Battery: 2× 18650 Li-ion cells
- Marketed Weight (with out battery)
- HD Model: 180 ±5g
- Analog Model: 174 ±5g
- Energy Equipment Model: 169 ±5g
- Weight (My Measurements)
- DJI O4 model with out batteries: 187.5g
- With 2× Molicel P30B 18650 cells: 278.5g
Design and Construct
The HGLRC Rekon35 V2 is a 3.5-inch, 2S FPV drone.
Straight away, it stands out due to its distinctive building. The drone contains a totally enclosed injection-molded plastic physique that protects all inside electronics, giving it a clear, skilled, and sturdy look.
One frequent concern with the DJI O4 Air Unit is overheating when powered on with out airflow. Fortunately, HGLRC addressed this with a big heatsink mounted beneath the air unit. I used to be in a position to depart the drone powered on the bench for over 5 minutes with none overheating warnings, which must be even much less of a priority throughout precise flight with fixed airflow.
HGLRC additionally changed the inventory linear-polarized O4 antenna with an extended circularly polarized antenna, bettering each vary and penetration. Based mostly on my testing, its efficiency is superb.
The flight controller and motors are mounted on a carbon fiber plate, with 3mm-thick arms that really feel very stiff and strong.
There are two rows of vibrant RGB LEDs on either side of the drone. Fly this factor at night time and it genuinely appears like a tiny UFO gliding by the air. The LEDs are configurable in Betaflight and can be utilized to show helpful data similar to GPS standing, throttle degree, or battery voltage degree. Out of the field, they default to a rainbow impact.
Study configuring Betaflight LED on this information: https://oscarliang.com/setup-led-betaflight/
The drone is powered by two 18650 cells housed in a hinged battery compartment (battery shouldn’t be included). Merely insert the batteries and also you’re able to fly.
Even higher, you possibly can depart the batteries contained in the drone and cost them instantly by way of the USB-C port on the rear like a DJI Mini, which is extremely handy.
The “no uncovered wires” design is certainly one of my favourite features—every little thing appears clear, modern, and effectively protected.
You’ll be able to entry the DJI O4 Air Unit’s USB port and bind button from the edges of the drone.
To attach the drone to Betaflight, there’s one other USB-C port situated just under the charging port. You’ll must push the spring-loaded antenna mount downward to entry it.
Battery – It Solely Takes 18650!
Open the battery compartment by holding down the 2 locking tabs and lifting the duvet to disclose the battery tray—simply probably the most fascinating side of this drone.
The Rekon35 V2 does NOT help LiPo battery. As an alternative, it runs on two particular person 18650 Li-ion cells—sure, the identical cylindrical batteries you’d usually use in radios, flashlights, or vaping gadgets.
At first, this may sound limiting, however it’s truly the core id of the drone: long-range.
Li-ion batteries are extraordinarily in style for long-range FPV, however they’re normally assembled right into a battery pack and linked to the drone by way of an XT30 or XT60 connector like a normal LiPo. Straight inserting particular person 18650 cells into the drone itself is genuinely distinctive. Whereas we’ve seen comparable concepts earlier than, they had been restricted to 1S setups—that is the primary BNF FPV drone to do it on 2S.
Advisable 18650 Batteries
I’ve examined many various 18650 cells: https://oscarliang.com/best-18650-li-ion-battery/
Listed below are my suggestions:
Best choice
Good Alternate options
Vital: The battery holder solely helps flat-top cells. Button-top 18650s is not going to match.
Tear Down: What’s Contained in the Drone?
Disassembling the Rekon35 V2 is easy. There are solely 6 M2 hex screws securing the plastic physique to the body.
The very first thing that stunned me was the unconventional flight controller design. It seems HGLRC might have designed this board particularly for the Rekon35 V2—it’s lengthy and rectangular fairly than the standard sq. form. That is an all-in-one (AIO) board, integrating the ESC and ELRS receiver onto the identical PCB. The upside is a really compact format; the draw back is that if any main part fails, you’ll want to exchange all the board.
The GPS module is the HGLRC M100 Mini, which I examined final yr and located to be wonderful. Regardless of its tiny measurement, it makes use of a u-blox M10 chip, delivering sturdy efficiency. I sometimes get a GPS repair in about 1.5 minutes with 8 satellites, and after 10 minutes it usually locks onto 19 satellites.
The digital camera angle is adjustable, however you’ll must take away the entrance cover to entry the mounting screws. Out of the field, the angle is ready to round 20 levels, which is right for long-range cruising, so I didn’t really feel the necessity to change it. In the event you ceaselessly modify digital camera angle, you can most likely drill a small entry gap within the cover to keep away from eradicating it every time.
The drone additionally comes with a small bodily beeper hidden between the 2 USB port within the rear, which is fairly loud. In the event you crash in bushes or tall grass, this shall be extraordinarily useful for restoration.
Flight Efficiency
Easy, Quiet, and Surprisingly Refined
The very first thing I seen is simply how quiet the Rekon35 V2 is. It’s shockingly low-noise for a 3.5-inch drone—you possibly can barely hear it from 100 meters away, even when doing flips and rolls. It’s good for discreet cruising.
The second shock was how steady and easy it feels within the air. It comes with a reasonably aggressive PID and filter tune, which is strictly what I prefer to see in a BNF. This actually exhibits that HGLRC put real effort into tuning fairly than transport a generic setup.
However It’s Not Quick
It hovers at round 30% throttle at takeoff. At first, it feels fairly agile—you possibly can even do some freestyle strikes like flips, rolls, and split-S maneuvers. Nonetheless, a couple of minutes into the flight, you possibly can really feel the drone slowly shedding punch resulting from voltage sag, and it turns into more and more dangerous to try aggressive maneuvers as you’re continually warned about low voltage.
This isn’t a freestyle machine; it’s finest fitted to relaxed cruising.
High velocity is round 70–80 km/h, and cruising sometimes sits between 40–50 km/h at roughly 40–45% throttle.
Lengthy Flight Time
The marketed 15-minute flight time is pretty correct for sluggish cruising. Realistically, it’s best to count on 12–14 minutes if you happen to fly up and down ceaselessly and blend in some freestyle strikes right here and there, particularly with some wind.
In calm circumstances with regular cruising, masking 10km or extra is totally achievable.
Not the Greatest in Windy Situations
The Rekon 35 V2 doesn’t deal with wind significantly effectively. In 20mph wind, the quad struggled considerably and was barely shifting into headwind.
With LiPo batteries, you can usually simply punch by wind, however with Li-ion cells, there’s little throttle response resulting from voltage sag. In the event you fly too far out in windy circumstances, there’s an actual threat chances are you’ll not make it again, so keep away from pushing distance when wind is robust.
GPS Rescue Labored Nicely
GPS Rescue is configured out of the field, and failsafe is ready to Rescue mode.
In my testing surroundings, GPS Rescue labored effectively and introduced the drone again near the takeoff level.
That stated, it’s best to at all times double-check your Rescue mode settings to make sure they fit your flying surroundings.
Take a look at my information on Rescue Mode: https://oscarliang.com/setup-gps-rescue-mode-betaflight/
Present Sensor Wants Calibration
My Molicel P30B has an precise capability of round 2851 mAh, however the OSD reported 6036 mAh—greater than double the true worth. The present sensor scale clearly wants calibration.
Limitations and Potential Enhancements
With this quad, battery high quality issues lots. You will need to use first rate 18650 cells—low cost or counterfeit batteries will utterly destroy the expertise. Sadly, faux 18650s are frequent on eBay and Amazon, which might frustrate newbies who aren’t aware of sourcing high quality cells.
The drone can be barely heavy for a 3.5-inch quad, weighing 187g with out batteries. In case your aim is to remain underneath the 250g weight restrict, this might not be the most suitable choice out of the field. That stated, I have already got a couple of concepts to cut back weight and enhance effectivity, and I consider it must be doable to deliver it underneath 250g. I’ll attempt to cowl these modifications in a future publish or replace this evaluation after the New 12 months when I’ve extra free time.
Battery Charging
You’ll be able to cost the batteries contained in the drone by way of USB-C, with a charging energy of round 11–12W. This implies it takes roughly 2 to 2.5 hours to totally cost two 3000mAh 18650 cells.
Charging seems to cease at round 4.15V per cell, which is definitely an excellent signal—it doesn’t overcharge. Nonetheless, it doesn’t attain the total 4.20V, so that you’re probably shedding a tiny quantity of capability (roughly 50mAh, or about 10 seconds of flight time). In follow, that is negligible.
In the event you want, you possibly can take away the cells and cost them with a devoted 18650 charger, or perhaps a LiPo charger utilizing a DIY holder like this. These strategies are prone to be a lot sooner and ensures a full 4.2V cost. Nonetheless, charging instantly contained in the drone is extraordinarily handy, good for lazy individuals like me 🙂
The way to Setup
Handbook may be very useful.
Firmware
- FC Board: HGLRCH743, comes with BF 4.5.2
- ESC Firmware: Bluejay, 0.21.0 (F-H-40)
- ELRS Receiver: HGLRC Hermes 2.4GHz RX (3.5.3 firmware)
Binding ELRS receiver
Detailed directions may be discovered right here: https://oscarliang.com/bind-expresslrs-receivers/
Pairing DJI Goggles
Observe the directions right here: https://oscarliang.com/how-to-setup-dji-o4-lite/#Pairing-DJI-Goggles-3-with-O4-Lite. The O4 doesn’t require activation, so you possibly can fly as quickly because it’s paired.
Betaflight Setup
- Energy & Battery tab: The settings are left at Betaflight default, that are for LiPo batteries, so low-voltage warnings will set off means too early. For 18650, it’s best to set Minimal Cell Voltage to 3V (depends upon the cells you might be utilizing, some can safely go as little as 2.8V and even 2.7V). Most Cell Voltage to 4.2V. Warning Cell voltage to three.2V. Present sensor scale additionally wants altering – I’ll publish my worth on a later date.
- PID Tuning tab: Arrange your individual charges.
- Modes Tab: Configure your arm change, angle mode, and turtle mode. For steering, see this tutorial: https://oscarliang.com/betaflight-modes/#How-to-Setup-Arm-Swap
- Receiver tab: Allow Telemetry
- GPS tab: My common settings are to allow “Use Galileo” and “Set Dwelling Level As soon as”, set Floor help Kind to Auto
- OSD tab: Customise to your choice.
Putting in Propellers
Insert the translucent bushings into the prop hubs, mount them on the motors, and safe every prop with two screws.
Vital: The Rekon35 V2 makes use of reversed motor route.
That’s it—your Rekon35 V2 ought to now be prepared for its maiden flight.
Closing Ideas: Is the HGLRC Rekon35 V2 Value It?
The HGLRC Rekon35 V2 is a daring experiment—a drone constructed totally round 18650 Li-ion. One essential level is that you will need to use good-quality cells; poor batteries will end in irritating efficiency.
HGLRC clearly invested numerous effort into the design. That is probably the most well-thought-out Li-ion-only FPV drone I’ve examined thus far. GPS Rescue works effectively, the quad is environment friendly, quiet, easy, and cleverly engineered.
Get the Rekon35 V2 from:
That stated, I do want HGLRC had made the drone lighter, ideally maintaining it underneath the 250g weight restrict. Because it’s not designed for freestyle or high-speed flight, the cumbersome building feels pointless. I consider a big portion of the plastic may very well be eliminated to cut back weight.
Even in inventory type, a 5 km spherical journey is totally doable, which is spectacular. Making it lighter would solely improve its potential.
The Rekon35 V2 shouldn’t be good, however it’s genuinely fascinating. And in a pastime filled with look-alike drones, that alone is refreshing.