DRL Racer 4s - HD Zero BNF + USED DRL 5s Battery

DRL Racer 4s - HDZero

An original DRL Racer4s, upgraded with an HDZero digital video system, an ExpressLRS receiver, and updated Betaflight firmware. This configuration pairs the Racer4s platform with equipment you can use with your own compatible radio and goggles.

Installed Hardware & Firmware

The original proprietary DRL receiver and video transmitter have been removed and replaced with:

• RadioMaster XR1 ELRS receiver, updated to ExpressLRS 4.x.
• HDZero Race V2 video transmitter.
• HDZero Nano 90 V2 camera.

The flight controller has been flashed with Betaflight 26.1 using our custom HOAR4s target. The HDZero/Betaflight on-screen display is fully functional. Smartaudio style commands are not currently working but stick commands and OSD for channel changes works fine.

Important: Updated Flight Configuration

This firmware upgrade replaces the original DRL flight-controller configuration. The original tune, rate profiles, and settings are no longer installed. Expect the drone’s flight characteristics and control feel to differ from its original DRL configuration.

The original DRL Betaflight 3.6 configuration dump will be available in our technical documentation for reference or for owners interested in returning to the original firmware and configuration. Restoring it requires the corresponding compatible firmware; the original dump should not be applied directly to Betaflight 26.1.

What’s Included

• DRL Racer4s with the installed HDZero video system and ELRS receiver.
• Updated firmware and configuration as described above.
• One set of 7-inch race propellers.
• Instructions for cycling through the available LED colors.

A battery is not included. You will also need a compatible ExpressLRS transmitter or transmitter module and an HDZero-compatible viewing setup.

LED Colors & Optional Button

The drone’s LED colors can be changed without adding an external button, but doing so requires access to the internal controls. Instructions are included.

For easier access, add the optional LED color-change button to your cart separately if you would like one installed.

Condition & Pre-Shipment Testing

This is a converted, previously used DRL drone. Cosmetic wear may be present.

Before shipment, each drone is:

• Powered on to confirm LED operation.
• Checked to confirm the receiver is configured.
• Test-hovered to verify basic flight operation.

The test hover is a basic operational check. You may still want to adjust rates and other flight settings to suit your preferences before race use.

Expected to ship: October 1st

Watch the launch video for a closer look at the drone, the conversion, and additional details:
https://www.youtube.com/watch?v=6tlr1lD9flw

USED DRL Racer 4 5s Battery Pack

This is the original battery pack used in the DRL Racer4s. The label lists it as a 2300mAh 5S pack, although based on its size, weight, and performance, I suspect that capacity rating is generous. Actual capacity has not been verified.

Let’s be clear: these batteries are VERY used, and you’re paying for rarity—not fresh cells or impressive performance. This is the only lot I was able to secure for the store. If the price doesn’t make sense to you, I completely understand. I’m happy to keep them for myself.

What you should know:

• Condition: Heavily used; what I would describe as fair condition.
• Testing: Packs are at storage voltage, but I have not cycled or capacity-tested them. Remaining life and performance are unknown.
• No performance guarantee: You could receive a weak or nonfunctional pack.
• Battery safety: These used packs may fail during charging or use, including catching fire. Inspect before use, use an appropriate balance charger, and never charge unattended. Do not charge a swollen or damaged pack.
• Purchase limit: One battery per Racer4s purchased in the same order, while supplies last. We have fewer batteries than drones.
• Shipping: Ground shipping only.
• Sold as is.

Please understand the condition and uncertainty before purchasing. These are original DRL packs with a racing history—not new batteries.

Firmware & Files:
https://drive.google.com/drive/folders/1eaGZFEpuia18d4xntFWQE_yKxnLlaL5y?usp=sharing