Viofo HK6 vs HK4 — Which is Best for the A329S Dashcam Parking Mode?

Introduction

I'm Ben from Safe Drive Solutions and in this hands-on comparison I walk you through the real differences between the Viofo HK4 and the new HK6 hardwire kits, and why you might choose one for your Viofo A329S. If you want reliable parking mode, low-battery protection and easy installation, this guide will help you decide.

HK4 hardwire kit unboxed showing selector and USB-C cable

Quick summary — the key differences

  • HK4: Simple, single-module hardwire kit with built-in low-battery protection selector and a USB-C output for the dashcam.
  • HK6: Two-piece module with detachable cables and an always-on Bluetooth broadcaster. Adds voltage readout and direct integration with supported Viofo models.
  • Both kits provide low-battery protection, ACC (ignition) wiring and support continuous parking mode recording — but the HK6 offers extra real-time voltage info and voltage cutoff feature for hybrid parking mode.

Outline

  • Unboxing and physical differences
  • How HK4 behaves with the A329S
  • How HK6 behaves with the A329S (Bluetooth/voltage features)
  • Real-world test: parking mode switching and low-battery shutdown
  • Which one should you get?
  • Where to buy, install and support

Unboxing & physical differences

I unpacked both kits side-by-side so you can see what's different at a glance.

  • HK4 arrives as a single cable assembly: a compact box containing the voltage cutoff selector, a USB-C plug for the dashcam and the three vehicle wires (red=12V, yellow=ACC/ignition, black=ground).
  • HK6 comes as a slightly more modular setup. It has a main Bluetooth-enabled module and two detachable cables that plug into it (a four-pin and a three-pin connector). The vehicle side still has red/yellow/black wires.

HK6 hardwire kit showing two detachable cables and Bluetooth module

How the HK4 works with the Viofo A329S

With the HK4 plugged into the A329S, the dashcam powers up normally and you can configure parking settings through the camera's on-screen menu. One source of confusion I clear up: the A329S does not lose low-battery protection if you use HK4. The HK4 has low-battery protection built in (selector for 11.8 / 12.0 / 12.2 / 12.4 V).

On the camera you can still set:

  • Parking mode type (Hybrid, Time-lapse, Low bitrate/event or Low current impact detection)
  • Cut-off timer (how long to stay in time-lapse / low bitrate before switching)

A329S showing 'no Bluetooth hardwire kits' when HK4 is connected

Note: if you try to access the 'cut off voltage' option on the A329S while using HK4, the camera will show a notice stating "no Bluetooth hardwire kits" — that menu prompt refers specifically to the Bluetooth-enabled HK6. That doesn't mean the HK4 lacks battery protection — it simply doesn't broadcast voltage via Bluetooth to the camera.

How the HK6 works with the Viofo A329S — Bluetooth and voltage readout

Plugging in the HK6, the A329S detects it and displays "discovered the hardwire kit." This is the main functional difference: the HK6 broadcasts the vehicle battery voltage via Bluetooth to the dashcam and can embed a live voltage readout onto recorded video. If seeing the real-time voltage on recordings matters to you, this is an added benefit.

A329S displaying 'discovered the hardwire kit' message with HK6 connected

Because the HK6 communicates with the camera, the camera's menu exposes the 'cut off voltage' options (12.4, 12.2, 12.0 V) directly. Now you can choose a precise voltage threshold inside the dashcam settings. When the vehicle voltage drops under the selected threshold, the unit will automatically switch to low-current parking mode.

Real-world tests: parking mode switching and shutdown timing

I tested both kits under the same conditions so you can see exactly how each behaves.

HK4 test

  • I set the HK4 to a low-battery cutoff (~below 12V) and placed the A329S into parking mode (hybrid mode, 2 hours of low bitrate/time-lapse before switching to low-current impact detection).
  • After dropping the test voltage below the threshold, the dashcam took roughly 90 seconds to shut down — the low-battery protection triggered and the camera powered off.

HK6 test

  • With the HK6 connected the A329S immediately detected the hardwire kit and allowed me to set cut-off voltages from the camera menu (12.4/12.2/12.0 V).
  • I set 12.4 V and used hybrid parking mode. When I dropped the voltage to 12.0 V, the dashcam automatically moved from low-bitrate parking recording to low-power impact detection (the LEDs turned off and the camera went into low current draw).
  • Dropping voltage further (to ~11.4 V) confirmed the HK6's two-stage protection: after about 90 seconds the camera fully shut off to protect the vehicle battery.

A329S in low-bitrate parking mode with LEDs on indicating parking recording

Timing note: in most of my tests switching between parking stages or full shutdown takes about a minute to a minute-and-a-half. That aligns with how the A329S handles parking routines and the hardwire kit thresholds. Our video does a better job explaining this.

So which should you choose: HK4 or HK6?

Short answer: both work and both protect your battery — choose based on the extra features you want.

  • Get the HK4 if you want a simple, reliable hardwire solution with low-battery protection and you don't need voltage telemetry embedded in recordings.
  • Get the HK6 if you want on-camera voltage readout, Bluetooth detection and tighter menu integration (cut-off voltage set from the camera). The HK6 is slightly more flexible thanks to detachable cables and the ability to extend/replace connectors.

Installation, support and where to buy

If you want to buy either kit or get professional installation, we have both available:

  • HK4 product: https://safedrivesolutions.com/products/viofo-hk4-hardwire-kit
  • Viofo A329S & accessories: https://safedrivesolutions.com/products/viofo-a329-2ch-first-4k-60fps-front-and-2k-rear3
  • Support for Viofo models: https://safedrivesolutions.com/pages/support-viofo
  • Parking mode explanation and why it's useful: https://safedrivesolutions.com/blogs/resources/dash-cam-parking-mode
  • Professional dash cam install (Vancouver & Toronto): https://safedrivesolutions.com/pages/dash-cam-installation
  • Home page and contact: https://safedrivesolutions.com/

If you prefer to have the kit professionally installed, Safe Drive Solutions offers mobile installation across Greater Vancouver and Greater Toronto. We also bundle cameras and installs to save money — sometimes $100 or more on camera + install + accessories.

Final thoughts

Both the HK4 and HK6 protect your car battery and enable parking mode for the A329S. The HK6's Bluetooth voltage broadcast and camera integration are nice conveniences — handy if you want voltage telemetry in your footage or easier in-menu configuration. The HK4 remains a solid, no-nonsense choice if you want a simpler, dependable hardwire kit.

"The main difference is you're actually going to get voltage — the HK6 broadcasts the car battery voltage to the dashcam and can embed it in your recorded video."

If you have questions about which kit fits your vehicle or want a free quote for installation, check our dash cam install page or contact us through the site.

Related reading and resources:

  • How to hardwire a dash cam: https://safedrivesolutions.com/blogs/resources/how-to-hardwire-a-dash-cam
  • Dash cams and battery safety: https://safedrivesolutions.com/blogs/resources/car-battery-die-from-dashcam-dash-cam-low-battery-protection
  • Viofo product collection: https://safedrivesolutions.com/collections/viofo-dash-cam
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