Whether you are pushing through a high-intensity interval session on the trainer, pacing a marathon, or climbing the virtual mountains of Zwift, accurate data is the foundation of every great training block. The 4iiii Viiiiva Heart Rate Monitor is a precision instrument designed to capture the most accurate picture of your internal physiological effort, providing the real-time data you need to optimize your performance and manage your recovery with professional-grade accuracy.

This complete guide will walk you through everything you need to know about your Viiiiva Heart Rate Monitor-from its core features to pairing, maintenance, and troubleshooting.

What Makes the 4iiii Viiiiva Heart Rate Monitor Different?

The Viiiiva is more than just a heart rate monitor. It connects over both ANT+ and Bluetooth, works with a large range of head units, sport watches, and training apps, and pairs seamlessly with the 4iiii app. Accurate, reliable, and built to last through your toughest workouts - the Viiiiva gives you the heart rate data you need to train smarter.

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FEATURES

What Features Does the 4iiii Viiiiva Heart Rate Monitor Have?

• 540+ Hour Battery Life — With over 540 hours of life from a single CR2032 coin cell, you won’t have to worry about frequent battery changes.
• ANT+ & Bluetooth Connectivity — Get the exact same numbers training inside and outside. The Viiiiva broadcasts simultaneously over both ANT+ and Bluetooth (BLE), making it universally compatible with your preferred cycling head unit, GPS smartwatch, and favorite indoor training apps.
• IPX7 Water Resistance — Engineered for durability, the IPX7 water-resistance rating ensures your heart rate monitor keeps pace with you, handling your most sweat-soaked and grueling training days.
• Professional-Grade Precision — The Viiiiva utilizes a high-sensitivity chest strap to capture your heart’s electrical activity (from 30 to 240 BPM), giving you a real-time window into your internal physiological stress.
• The Ultimate Power Couple — The Viiiiva is the perfect partner for your 4iiii PRECISION 3+ Power Meter. While power measures your external output (watts), heart rate tracks your internal physiological response (bpm). Together, they allow you to optimize your training zones and track fitness gains with total precision. Learn more here.

4iiii Viiiiva Heart Rate Monitor Technical Specifications

Parameter	Specification
Battery Type	CR2032 Coin Cell
Battery Life	540+ hours
Waterproof	IPX7
Operating Temperature	-20°C to 70°C
Heart Rate Unit	BPM
ANT+	Yes
Bluetooth	Yes (BLE)

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SET UP

Where to Find Your 4iiii Viiiiva Heart Rate Monitor Manual

Here’s everything you need to get your Viiiiva Heart Rate Monitor set up and ready to train.

• Viiiiva Setup Page — An intuitive, easy-to-navigate guide to help you get started.
• Viiiiva Quick Start Guide — A short summary of how to get started. Great for getting up and running fast.
• Viiiiva User Manual — The complete set of instructions, covering everything from installation to settings and troubleshooting.

How to Wear Your 4iiii Viiiiva Heart Rate Monitor

Getting accurate heart rate data starts with wearing the Viiiiva correctly.

1. Wet the conductive pads on the strap with a few drops of water to ensure good contact with the skin.
2. Wrap the strap around your chest and attach the pod by sliding it down onto the connectors. Make sure the arrows on the back of the pod are pointed up.
3. Adjust the strap to fit snugly just below your pectoral muscles with the pod centred.

Note: Inaccurate heart rate data will be detected if the pod is worn upside down.

How to Pair the 4iiii Viiiiva Heart Rate Monitor with the 4iiii App

Download the free 4iiii app on the Apple App Store or on Google Play.

1. Open the 4iiii app and log in. If this is your first time, create an account.
2. Moisten the conductive pads and put on your heart rate monitor to wake it. 3. Select Add a Device.
3. Select your Viiiiva from the list of available devices. A check mark indicates it is selected.
4. Press Connect.

How to Pair the 4iiii Viiiiva Heart Rate Monitor with a Display Unit

The Viiiiva pairs with ANT+ and Bluetooth head units and smartwatches. Pairing steps vary between devices - consult your head unit or watch manufacturer for specific instructions.

Generic ANT+ pairing steps:

1. Turn on your display unit.
2. Moisten the conductive pads and put on your Viiiiva to wake it.
3. Go to the Settings menu, then Sensors.
4. Select Add Sensor, then Heart Rate.
5. Select your Viiiiva from the list of ANT+ IDs.

Generic Bluetooth pairing steps:

1. Turn on your display unit.
2. Moisten the conductive pads and put on your Viiiiva to wake it.
3. Navigate to the Sensors menu on your display unit.
4. Add a new sensor and select your Viiiiva from the list.

Once paired, most display units will remember your Viiiiva and automatically connect when both devices are on.

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MAINTENANCE

How to Replace the Battery in Your 4iiii Viiiiva Heart Rate Monitor

The Viiiiva uses a standard CR2032 coin cell battery. Replacement batteries can be purchased wherever batteries are sold.

Tip: We recommend avoiding CR2032 batteries with a bitter coating as it has been shown in tests to be non-conductive. This can lead to connection problems or dropouts with your 4iiii heart rate monitor.

1. Remove the battery cover by prying it with a flathead screwdriver or similar tool.
2. Use the same tool to gently pry the battery from the cap.
3. Place the new battery into the cap with the ‘+’ symbol facing the battery cap.
4. Return the cap to the pod and snap it into place.

Note: Batteries must be disposed of properly, including keeping them away from children. Even used batteries may cause injury if ingested.

How to Clean Your 4iiii Viiiiva Heart Rate Monitor — Two Minutes, No Excuses

Keeping your heart rate monitor clean is simple - just use the right materials.

• Separate the pod from the strap before cleaning.
• Prepare a mixture of warm water and mild soap, then hand wash the strap.
• Using a soft rag dipped in the mixture, wipe down the pod.

Do not wash the strap in a washing machine - it can damage the sensors.
Do not have liquids near the pod when the cap is off for maintenance.

Store your Viiiiva in temperatures no colder than -20°C (-4°F) and no warmer than 70°C (158°F).

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TROUBLESHOOTING

My 4iiii Viiiiva Heart Rate Monitor Won’t Connect or Pair - What Do I Do?

If your Viiiiva Heart Rate Monitor isn’t showing up in the scan list, try the following:

1. Make sure your Viiiiva is awake - moisten the strap contacts and put it on.
2. Replace the battery with a fresh CR2032. Avoid bitter-coated batteries as these can cause connection issues.
3. Make sure Bluetooth is enabled on your smartphone.
4. Close the 4iiii app and relaunch it.
5. For Bluetooth: ensure the Viiiiva is not already connected to another device or app. The Viiiiva can only be connected to one Bluetooth device at a time delete it from all other apps before reconnecting.
6. If none of the above works, delete and reinstall the 4iiii app.

My 4iiii Viiiiva Heart Rate Monitor Is Reading Zero or Incorrectly What’s Wrong?

Inaccurate or zero heart rate readings are almost always caused by a fit or contact issue. Check the following:

• Ensure the Viiiiva is worn right-side up the arrows on the back of the pod must point up. Inaccurate data will result if the pod is worn upside down.
• Ensure the strap is snug and positioned just below your pectoral muscles.
• Ensure the conductive pads or patches are wet they need good contact with the skin.
• Replace the battery with a fresh one.
• Wash the strap - a buildup of sweat and salt can affect conductivity. See the Maintenance section above.

My 4iiii Viiiiva Heart Rate Monitor Is Dropping Out or Losing Connection

1. Replace the battery with a new CR2032 - avoid bitter-coated batteries.
2. Ensure the strap contacts are clean and the pod is making good contact with the strap.
3. For Bluetooth: ensure no other device or app is connected to your Viiiiva simultaneously.

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GENERAL FAQS

What Features are Different Between the Original Viiiiva and Viiiiva 2.0?

The Viiiiva 2.0 is our streamlined, ultra-efficient current model focused purely on flawless real-time data broadcasting, a long-lasting battery, and a more comfortable, user-friendly strap. While the Viiiiva 2.0 prioritizes everyday comfort and simplicity, the Original Viiiiva included a few specialized onboard features like ANT+ bridging and activity logging.

For more details on the Original Viiiiva, visit the 4iiii Help Center.

Which Apps Work with the 4iiii Viiiiva Heart Rate Monitor?

Because the 4iiii Viiiiva broadcasts your data simultaneously over both ANT+ and Bluetooth (BLE), it is universally compatible with almost any modern training app, cycling head unit, or GPS smartwatch.

Whether you are logging indoor miles or tracking an outdoor ride on your phone, the Viiiiva seamlessly pairs with the most popular platforms in the cycling world.

• Indoor Training & Virtual Cycling Apps: Fully compatible with Zwift, Trainer Road, Wahoo SYSTM (formerly The Sufferfest), Rouvy, and FulGaz.
• Fitness Tracking Apps: Easily pairs via Bluetooth to smartphone apps like 4iiii Ride, Strava, MapMyRide, and Apple Health.
• Head Units & Watches: Connects flawlessly via ANT+ or Bluetooth to Garmin Edge computers, Wahoo ELEMNT units, Hammerhead Karoo, Apple Watch, and Garmin Forerunner/Fenix watches.

Does the 4iiii Viiiiva Heart Rate Monitor 2.0 Support HRV?

No, the 4iiii Viiiiva 2.0 does not support Heart Rate Variability (HRV). These were legacy capabilities exclusive to the original model.

Instead of resting HRV metrics, the 2.0 Viiiiva is completely optimized for active training. It focuses its firmware and battery power entirely on delivering highly stable, medical-grade real-time heart rate data (BPM) simultaneously over ANT+ and Bluetooth for upwards of 540 hours of riding and running.

Does the 4iiii Viiiiva Heart Rate Monitor 2.0 Support ANT+ to Bluetooth Bridging?

No, the 2.0 Viiiiva does not support ANT+ to Bluetooth bridging. The bridging capability, along with onboard activity logging, were legacy features exclusive to the original models.

The 2.0 Viiiiva is engineered to be as streamlined, stable, and battery-efficient as possible. While it does not act as a bridge for other third-party sensors, it flawlessly broadcasts its own highly accurate heart rate data simultaneously over both ANT+ and Bluetooth, ensuring it connects perfectly to any head unit, smartwatch, or indoor training app.

Is the 4iiii Viiiiva Heart Rate Monitor Waterproof?

The 4iiii Viiiiva Heart Rate Monitor is highly water-resistant with an official IPX7 rating. While it is not designed for underwater swimming, it is completely sweatproof and built to withstand the heaviest rainstorms on your ride.

The IPX7 rating means the pod can safely survive being submerged in up to 1 meter of water for 30 minutes. To maintain this water resistance, always ensure the red O-ring inside the battery compartment is seated perfectly in place whenever you change the battery.

What Battery Does the 4iiii Viiiiva Heart Rate Monitor Use?

The 4iiii Viiiiva Heart Rate Monitor uses a standard CR2032 coin-cell battery. This easily replaceable battery provides upwards of 540 hours of continuous use before needing to be swapped.

When replacing the battery, just make sure the red O-ring inside the battery compartment remains perfectly seated to maintain the pod’s waterproof rating.

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Ready to Train Smarter?

Whether you are tracking recovery, pacing a threshold effort, or logging base miles, the 4iiii Viiiiva Heart Rate Monitor is the ultimate tool to keep your training dialed in. Armed with over 540 hours of battery life and universal connectivity, it is ready to work exactly when you are.

If you ever run into setup issues or have technical questions, our support team is always ready to help you get connected. Grab your strap, moisten the contacts, and go crush your next workout!

Have more questions? Visit the 4iiii Help Centre

Ready to take your training to heart? Shop the 4iiii Viiiiva Heart Rate Monitor