Best LTE Smartwatches That Make Calls without Phone 2022

Noor August 14, 2022

If you’re looking for a way to make calls without phone, consider picking up an LTE smartwatch. LTE stands for Long-Term Evolution, and it is a type of cellular network that offers high speed and low latency.

LTE smartwatches are similar to regular smartwatches, but they connect directly to cellular networks, so you can make calls without a phone. And because calls are made over a cellular connection, there’s no need to worry about spotty WiFi or dropped calls.

Moreover, with these LTE cellular watches, you can also send/receive messages, emails, browse the internet, and can make audio video calls independently over WhatsApp, Facebook and etc.

Whether you never own a phone or just want to leave your phone at your home, an LTE smartwatch is a perfect way to stay connected without being tethered to your phone.

There are a number of different LTE smartwatches on the market, so it can be tough to decide which one is right for you. If you’re looking for the best option out there, we recommend checking out the list below.

10 LTE Smartwatches To Make Calls Without Phone

Image	Product	Features	Price
	Apple Watch Series 5 (GPS + Cellular, 44MM)	4G/LTE Advanced Health monitors Apple Pay	Check Price
	Apple Watch Series 3 (GPS + Cellular, 38MM)	Swim-proof design 4G LTE connection Optical Heart sensor	Check Price
	TicWatch Pro 3	Dual-layered screen 4G LTE Connection Fitness/Health tracking	Check Price
	SAMSUNG Galaxy Watch 4	LTE connection Military durability Fitness tracking	Check Price
	SAMSUNG Galaxy Watch Active 2	LTE connectivity Bixby 2-day battery life	Check Price
	Garmin Vivoactive 3	Verizon subscription Songs storage/playback Texting/calling	Check Price
	Samsung - Gear S3 Frontier Smartwatch	Rotatable stylish bezel LTE connectivity Samsung Pay	Check Price
	Padgene DZ09	Standalone watch Bluetooth Texting/Calling Pedometer	Check Price
	TickTalk 4	4G LTE connection 2-way texting/calling Efficient positioning	Check Price

1. Apple Watch Series 5 – Cellular Smartwatch for iPhone Lovers

Apple plays the watch game like a pro. The very watch offers you a Cellular network option along with the option to pair with your cool iPhone.

Apple doesn’t disappoint here. It justifies the extra dimes you pay by providing a beautifully designed watch laced with a large AMOLED screen. Apple Watch 5 boasts the typical and renowned Apple Watch design (i.e., a square-shaped dial).

This watch sees a 30% increase in screen size as compared to the predecessor. The Retina display shall soothe your eyes, and Always-On display provides you with details at a glance.

The speaker and the microphone’s performance are above par. A noise app alerts you of extreme increases in sound that may affect your hearing, ensuring a balanced delivery of decibels. Making calls and receiving them will be a NO-PROBLEM with this feature beast.

Apple Watch Series 5 is built to endure the atrocities of the water. A waterproofing till 50m makes it an obvious choice for the swim-lover community.

Powered by the latest technology, this watch supports a 4G LTE connection. A blazing-fast 4G LTE connection ensures a smooth calling, texting, and browsing experience on your smartwatch Phone. Replying to texts is an out of the world experience with different methods to type in, with the Scribble feature being an uncanny one.

This bad boy from the Apple house empowers you with a myriad of beneficial features. It is laced with the latest and most precise optical heart-rate sensors. Female health tracking is added to keep women updated.

GPS incorporated with an intelligent fitness app encourages you to burn some muscle through outdoor activities. The activity data paired with your physique data is used to measure the number of calories you burnt. Swim-proofing promotes in-pool activities. Activity rings track your progress and act as your personal trainer.

You can enjoy your favorite melodies by streaming and downloading your favorite apps from AppStore. Apple Watch 5 is not just a replacement for your phone but also for the wallet, thanks to the mobile payment option via Apple Pay.

Key features:

• GPS and Cellular network
• Large Always-On Retina display
• AMOLED screen
• Waterproof
• Advanced Heart-rate Sensors

Pros:

• Large Always-On AMOLED display
• 4G LTE Cellular connection
• Waterproofing
• Advanced Health monitors
• Apple Pay

Cons:

• Very expensive
• Battery life is just 18 hours at max

Bottom line: This is for sure one of the best Apple watches with an LTE/4G cellular option. The blazing-fast 4G connection sitting atop the multitude of useful features is a green signal for Apple lovers.

2. Apple Watch Series 3 – iOS Compatible Watch To Make Calls

It’s a difficult task getting out of the magic of Apple products. This is why Apple Watch 3 is among the best smartwatches that work without a phone.

Apple follows its style statement, which is a good business strategy. Thus, you will find the typical squarish dial which attracts many. The option to change straps adds to the beauty of this watch, which can be bought separately. The Screen size is pretty decent to be used as a smartphone watch, thanks to the Retina Display.

As per the user’s reviews, the speaker is loud enough to allow frequent receiving of calls on the smartwatch. The microphone is famous for recording and delivering clear sounds.

Apple Watch 3, just like Watch 5, provides a waterproof design. The swim-proof design of the smartwatch is a relief for the swimmers. An accurate record of the swimming strokes is recorded, attributed to the great waterproofing of the device.

This particular device is a GSM and an LTE smartwatch depending on the type of data package and the sim network you chose. A basic GSM sim will work fine. However, you can enjoy the fast network speeds of a 4G connection too. This texting smartwatch allows you to reply to text messages in 4 different ways, i.e., in the form of voice notes (speech-to-text), emojis, brief replies, complete texts. Moreover, calling features is also available, thus, providing freedom of use as a standalone watch.

An accurate measure of heart rate shall help you to notice the changes of exercise on the body or note any anomaly. Complete workout data is imparted to users. The number of steps, calories burnt, and goals achieved are there. The workout data paired with the heart monitor can help you deduce the effects of the workout and note the progress.

Location and position tracking for outdoor workouts are as accurate as GPS watches. The ultimately beneficial feature of the Apple pay service is available here. You can talk to Apple’s famous Siri assistant and listen to music by streaming it.

Key features:

• Retina display
• Swim-proof design
• 4G LTE connection
• Optical Heart sensor
• Apple Pay

Pros:

• 4G LTE connection
• Call and message option
• Waterproofing
• Apple Pay

Cons:

• Battery life is a mere 18 hours at max
• Still an expensive watch

Bottom line: This particular watch is an affordable version of the Apple family. It comes with great design and functionality, which makes it worthy of being used solely without a phone.

3. TicWatch Pro 4G – Smartwatch That Doesn’t Need Phone For Call & Text

This beast is a standalone smartphone. The features can suffice your smart needs and efficiently replace your Smartphone.

The beautiful round dial and the rugged design are appealing to the eye. The straps are comfortable and easily adaptable, especially the lightweight Silicone strap. The dual-layered screen will raise many eyebrows. An LCD screen sitting atop the crispy AMOLED screen provides a great viewing experience and battery-saving features.

TicWatch Pro 4G is designed to work as an individual device independent of Bluetooth pairing with a smartphone. The speaker and microphone perform exceptionally well.  You won’t regret using this for making calls.

Mobvoi has crafted this device to bear the harsh realities of life. It is tested to military standards of dust, shock, and humidity and is Military Standard 810G proof. IP68 waterproofing allows you to dive into the pool.

TicWatch needs data subscriptions to work individually. However, attractive plans exist for Verizon users. You can make phone calls and send instant and detailed text messages from this smartwatch. A 4G LTE connection ensures smooth data usage and the freedom to stream music and download apps.

It can last for a couple of days with average usage. An increased juice for 2-5 days can be seen by activating the Essential mode.

Tic Motion app detects your workout activities that include running and swimming, etc. more than 6 sports modes are bundled into the device.

An accurate sleep tracker can help insomnia patients while the top-notch TicPulse app efficiently updates you on your heart rate. The heart-rate monitor works 24/7 and gives notifications on any sudden abrupt changes in the rate.

Google OS provides a wide variety of options. With Google Pay, you no longer need to carry your hefty wallet anymore. Just use the mobile payment option.

Key features:

• Stylish design with Corning Gorilla protection
• Dual-layered screen
• 4G LTE Connection
• IP68 waterproofing
• Fitness and Health tracking

Pros:

• Dual-layered screen
• LTE connection
• Military resistance and IP68 waterproofing
• Instant calls and messages
• Google Pay

Cons:

• Battery life could have been better
• A little expensive

Bottom line: This watch is a lone warrior that can survive on its own. It’s a fine example of an android watch that can call and text on its own.

4. Samsung Galaxy Watch LTE Variant – No Phone Needed To Make/Receive Calls

A classic product from the Samsung brand, this watch supports a fast 4G network and extreme functionalities.

The Samsung Galaxy Watch is a big round dial watch. The case promises to look and feel premium. The user can choose from a collection of interchangeable bands. The 46mm model gives a 1.3-inch screen that is an Always-On AMOLED display. Viewing and operating the device is pretty easy.

The speaker on this smartwatch is loud enough to allow clear calls, and the microphone allows a good quality of sound to be transmitted.

The device lives up to its reputation as a Macho Watch. The durability features and the stylish manly looks sweep away the hearts of the men. Military-grade durability of the devices is a great plus point. The waterproofing strengthens the smartwatch against spills and splashes. Moreover, it imparts a swim-proof design to 5 ATM of water pressure.

The Samsung Watch supports the 4G LTE connection. Fast network speeds with advanced connectivity will make you aware of a faster world. The standalone watch that works with a sim offers the freedom to call, text, and stream music from the comfort of your wrist. You can receive notifications too. So, forget your phone behind and embrace the marvels of technology.

The battery life of the very watch soars above its competitors. This Smartwatch phone can last for a few days post a single charge.

All the usual smartwatch features are present here with a tint of premium. This machine encourages you to lead a balanced life. The fitness tracker working in conjunction with GPS is an efficient one. It tracks your walking, running, cycling, etc., activities. Guided meditation and stress exercises are a part of the program too.

Heart-rate monitoring is up to date. This watch automatically detects a shift in heart rate when you switch between workout activities.

Modern smartwatches have taken over smartphones. With Samsung Pay, you can make payments very easily. A flick of a wrist and tada! The transaction is done. There is a feature of HOME IoT that lets you connect and control different household objects.

Key features:

• LTE connection
• Good battery
• Military durability and waterproof watch
• Fitness and health tracking
• Samsung Pay

Pros:

• LTE connection
• Calls and SMS
• Military standard and waterproofing
• Samsung Pay

Cons:

• A heavy watch

Bottom line: The Macho watch is a decent replacement for the Smartphone. Smartwatch is crafted for the strong hands who want to get rid of the phone.

5. Samsung Galaxy Watch Active 2 – Best LTE Phone Watch For Android

Watch Active 2 is a great piece of technology that is determined to perform the best.

The product is a sheer performance-based device that hides a lot many features under the hood. The screen is a splendid AMOLED panel with a 1.2″ or 1.35″ screen size. The style of the watch is classy as the screen covers the dial completely and nicely.

The decibels from this speaker shall let you enjoy your Spotify playlist and YouTube videos. The microphone and the speaker quality are above par for making and receiving calls on the device.

No leaks or downgrades are seen in this department. A military 810G rating with Corning Gorilla protection assures the might of this beast against the attacks of dust, shock, and drops. Waterproofing of the upper level (up to 5 ATM) is seen, i.e., Swim-ready protection against the tides will be imparted.

The Samsung Active Watch 2 needs a sim card and a working network connection to work as a smartphone substitute. The LTE unlocked watch can work with most of the carriers and provide you with light-speed connectivity. Receiving and sending texts is easy and smooth. Call quality, too, is brilliant.

The battery easily lasts for a day, or on average usage, you can see 2 days of juice.

A lot depends on the Operating System of the device. Samsung’s tamed Tizen OS is a specialist for smartwatches. With the Active 2 smartwatch, you can level up your game of workouts. Innumerous activity modes are present in the watch. Running, treadmill and swimming, etc. are recorded accurately.

A continuous heart-rate scanner is your personal diagnostician and informs you instantly of any abrupt change in the rate. A sleep monitor is also available. Bixby is your personal assistant that shall obey all your commands and execute them. Samsung Pay allows you to pay for movie tickets and more stuff from the comfort of your wrist. You can receive rewards and offers too.

Key features:

• LTE connectivity along with BT
• A crispy AMOLED screen
• Advanced fitness tracking
• 2-day battery life
• Voice Assistant Bixby
• Samsung Pay

Pros:

• AMOLED screen
• LTE connection
• Text and Call option
• Samsung Pay

Cons:

• LTE variant is expensive plus subscription charges

Bottom line: This Macho watch is a decent replacement for the Smartphone. Watch is crafted for the strong hands who want to get rid of the phone and can wear a heavier watch.

6. Garmin Vivoactive 3 – Best Smartwatch for Answering Calls

Watch Active 2 is a great piece of technology that is determined to perform the best. It is a power pack of very beneficial features for a variety of people.

This member of the Garmin family comes with a 1.2-inch round dial screen which sits nicely on the wrist. Well sighted people shall have no issues in usage.

The speaker is the salient feature and the main selling point of the Garmin Vivoactive 3. The exceptional quality of the speaker not only allows a good music experience but also enhances the call quality. Thus, it’s the best watch for answering calls. The microphone compliments the speaker to ensure an out of the world calling experience. Additionally, sending text messages to friends works like a breeze.

Corning Gorilla protection saves the smartwatch against scratches. Waterproofing protects against splashes and drops of rain.

The manufacturers allow Subscriptions with Verizon to unleash a world of opportunities and possibilities. With a Verizon subscription, you can take advantage of texting without a phone, and safety tracking features.

Garmin Vivoactive 3 (with Subscription) allows safety features. When in danger, you can press the button on the watch for 3 seconds, and your emergency list contacts are notified of your condition with your real-time location. LiveTrack lets your friends track your position at the new coffee house.

An upsized battery is seen that can last a whopping 5 days in the smartwatch mode.

An uncanny feature of this smartwatch is the option to pair it with headphones via Bluetooth. So, you can replace your phone with this great device. To spice things up, the watch allows around 500 songs to be downloaded and played on the wrist. Music can be played on the GO, thanks to the fast Verizon LTE connection.

Outdoor workouts are now fun. The heart-rate elevation is instantly recorded by the Heartrate monitor, like dedicated fitness trackers with heart rate monitoring. The device is laced with a wide variety of fitness features. More than 15 sports modes exist that can cover almost every sport that you will be interested in.

GPS works in conjunction with the fitness app too. Garmin Pay allows mobile payment and frees of the annoyance of carrying a wallet.

Key features:

• Verizon subscription
• Songs storage and playback
• Texting and calling option
• Bluetooth headphone support
• Garmin Pay

Pros:

• Verizon LTE subscription
• Texting and calling option
• Song download and playback
• 15+ sports modes
• Garmin Pay

Cons:

• Only Verizon subscription available

Bottom line: The Verizon version of Vivoactive 3, is a great watch for those who want to enjoy music 24/7 and like to answer calls on their wrist without the need of a phone.

7. Wzpiss – Economical Smart Watch Phone

The Wzpiss watch is a prodigious yet affordable device. The features are like most of the competitors and that too below $30.

The Wzpiss watch is a solid device that mimics an Apple watch series in design. The IPS LCD screen is bright and proves to be an amazing offer at the given price. A large 1.54″ screen is easy to use and promotes shifting from Smartphone to a smartwatch. The watch is sleek, and the band boasts an ergonomic design that is breathable for the wrist skin.

This smartwatch comes with an in-built microphone and speaker. The speaker is loud enough to be used for music playback and answering calls. The microphone may not be the best amongst the competitors but is decent hardware.

The silicone strap is capable of bearing tough conditions and makes this watch strong. Though it lacks any certification of endurance but is a sturdy device. I can say this as I have used the device personally. Like many others, it’s a waterproof smartwatch.

Wzpiss smart watch offers 2 options to work. Either a connection with the smartphone via Bluetooth. The watch can pair with Android and IOS. The number of features provided when paired with the iPhone is limited.

This phone watch can work solely. For this matter, you need to have a 2G sim and a working data connection. A 2G Sim will allow you to receive and make calls from the smartwatch. Moreover, You can receive texts and reply to your loved ones too. It can also receive social media notifications such as Facebook, Twitter, and WhatsApp with ease.

The battery life of Wzpiss smartwatch can last for 3 days at maximum.

It has some health and fitness tracking facilities. A pedometer on the watch is good for activity tracking. It counts steps and measures the distance and number of calories burnt. You can put on this wearable while sleeping to inform you of the sleep quality, thanks to the sleep monitor.

An in-built camera is also available and it also has a memory card slot too that supports up to 32GB memory cards. You can store music in mp3 format. You can also store pictures and view them in the image viewer.

Key features:

• Texting and call option
• 2G sim option
• Breathable and sweatproof strap design
• Built-in camera
• Music player

Pros:

• 2G Sim
• Memory card for music storage
• Pedometer
• Text and call option
• Very economical watch

Cons:

• Lacks mobile payment
• Lacks heart-rate sensor and advanced features

Bottom line: The Wzpiss smartwatch is an affordable allrounder, which shall suffice your needs for a smartwatch that make calls without the need of a phone.

8. Samsung Gear S3 Frontier – Best LTE Smartwatch To use Without Smartphone

The LTE variant of the Samsung S3 frontier watch is a good device with some unique tricks up its sleeves.

The Samsung Frontier S3 has the unique design of all the competitors. The device feels like a machine from the future. The reason for this is a rotatable bezel, which is a gimmick and a functional aspect too. The 1.3″ AMOLED screen provides an eye-soothing viewing experience. The screen sits in circumference surrounded by a bezel. You can rotate the bezel to execute different functions on the smartwatch.

The speaker and the microphone are designed by keeping the mind the call capabilities. Both the hardware perform up to the mark in making calls.

The strength of the materials is exemplary. A military standard toughness is assured to the users. This means dust, extreme temperatures, and drops won’t affect this smartwatch that easily. Waterproofing is also available. So, you can plunge into the pool carefree.

The LTE variant is an unlocked version and allows LTE subscriptions of most of the network operators. Blazing-fast internet is assured. Texting and messaging with a phone paired is possible. Sole performance of the watch is also seen, attributed to the LTE sim inside the smartwatch.

The 380 mAh battery provides juice for around 3 days on average usage. A strong selling point of this smartwatch is the battery. However, LTE usage can drastically decrease battery time.

Samsung’s Tizen OS offers a wide variety of features. A mere rotating of the bezel performs certain steps. Texting and calling from this smartphone watch is a great experience.

Samsung Health is a tamed app that records your activities. Be it running, jogging, or yoga activity, the watch records all with accuracy and precision. GPS works in synchrony with fitness tracking to note the outdoor activities.

The Samsung Pay app allows you to carry out mobile payments without the need to carry a wallet.

Key features:

• A distinct rotatable bezel
• 3″ AMOLED screen
• Military-grade durability and waterproofing
• Samsung Pay

Pros:

• Rotatable stylish bezel
• Individual texting and SMS on LTE
• Waterproofing and durable materials
• Samsung Pay

Cons:

• Lacks advanced heart-rate sensor
• Watch is expensive

Bottom line: The Samsung S3 Frontier LTE watch is a watch with a futuristic design and superb functionality. The LTE connection allows fast working even without a phone.

9. Padgene DZ09 – Cheapest GSM Smart Watch With Sim Card

Padgene DZ09 is one of the best cheap smartwatches and has had all our attention for a long time. It has the magic of attracting buyers alike and it deserves all the attention and love of the users.

It boasts a good 1.54′ screen that shall pose no problem in the viewing experience. The OLED screen performs exceptionally well. The ergonomic and comfortable band compliments the attractiveness of the screen.

Keeping in mind the petty price tag, one must think that this smartwatch can barely perform the basics. Yet, here it is laced with a decent speaker and microphone. Voice quality on calls and music is nice.

DZ09 Padgene doesn’t provide much of tests and proof in terms of strength, but basic waterproofing shall save the watch against splashes and brief dips in the water.

The subscription options allow a 2G or a 2.5G sim to be installed. A safe working quality and a wider area of the network are ensured with 2G and 2.5G networks. The option to slide in a sim allows individual texting and calls from the watch without a smartphone.

Receiving social media notifications is easy. Be it WhatsApp, Facebook, or Twitter; the notification updates are just a glance away. An SD card can be inserted, allowing you to store images and soundtracks within the smartwatch. Thus, this is a real standalone smartwatch in the true sense.

A whopping 7-day long battery accompanies the device. The battery is too good to be true.

DZ09 tracks sports day well. It can record your number of steps, distance, and calories burnt. Sleep quality is also measured, thanks to the sleep monitoring capability of the smartwatch. Sleep quality is measured to determine stress levels.

Key features:

• Large OLED display
• Ergonomic and comfortable band
• Water-resistant
• Fitness tracking
• Smartphone watch
• Option to reply to texts

Pros:

• 54″ OLED screen
• Waterproof
• Standalone watch
• Text replies and messages
• Pedometer
• Very economical watch

Cons:

• Lacks a heart-rate tracker
• Lacks mobile payment option

Bottom line: This is a multi-functional watch that works solely and stays light on the pocket. A must-have for those who want a complete package with a smaller price tag.

10. TicTalk 3 LTE – Smartwatch For Teenager Without Phone

This particular device belongs to the kids smartwatch section, but this is a great kid phone watch too.

The TicTalk 3 watch is an attractive device for kids. The device boasts a large screen with a vivid and colorful display. The icons are catchy to the toddler’s eyes. The strap is full of colors and comfortable for the lad’s wrist.

This particular device is powered by a reliable speaker and a clear microphone. The young girls and boys can enjoy sweet melodies and maintain strong contact with their parents.

This watch is designed for the day-to-day usage of the kids. The materials are robust and sturdy. An IP67 rating on the watch means a dip in the water or a jump into the puddle by the toddler will not harm this smartwatch at all.

The connectivity options offered by this phenomenal device open up a world of opportunities. WiFi connectivity is a blessing. The kids can communicate with their parents at any time, thanks to the 4G LTE connectivity. 2-way calls and messages are plus points. An added feature of this smartwatch is the 2-way Video calling. Voice messages can be exchanged too. GPS. WiFi, LBS, and LTE are combined to update the child’s location to the parents, that too in real-time.

The battery life is good and a reliable device for kids.

A Firewall feature is a useful one for the parents. This allows children to call only the preset contacts by the parents. A 2MP camera on the smartwatch allows the kids to take pictures easily. The children can capture the moments and share the happy ones with family members. Kids can share emojis and GIFs too.

A Do Not Disturb Mode is beneficial for the kids during class times. It ensures the uninterrupted imparting of knowledge to the kids. Homework and feeding the pet reminders to the kids are sweet and attractive features for your offspring.

Key features:

• 4G LTE connection
• IP67 waterproofing
• 2-way messaging and calling
• Efficient positioning
• Comfortable band

Pros:

• 4G LTE connection
• WIFI connectivity
• 2mp camera
• Video, audio calling, and messaging
• Advanced positioning with GPS, LBS, and LTE
• Waterproofing

Cons:

• Lacks games for kids

Bottom line: This smartphone watch is an ideal buy for kids as it supports an LTE connection with a multitude of calling, messaging, and safety features.

What to look for before buying an LTE Phone Watch?

When going out to watch hunting, you must know the requirements. You should have the know-how of what to look for when selecting a solo device that shall provide all the features.

Design and Screen quality:

The very first requirement is the design of the watch. A safe way is to follow the trend and to pick the newer items over the obsolete ones, but this can be compromised for greater functionality. It’s imperative that the smartwatch provides a decent quality screen because this may become your daily driver and a replacement for your Smartphone.

Speaker and microphone quality:

A smartwatch that makes calls without a phone can only survive in the harsh world if it’s capable of proving its wits to stand alone. For this matter, the smartwatch must have a loudspeaker and a clear microphone, so that no issues are faced during calls.

Strength of materials:

Everyday usage items are prone to wear and tear. Smartwatch is meant to stay on your wrist for a pretty good time, and in the ordeal, it has to endure different environments. A sturdy smartwatch is recommended, owing to the nature of the watch.

Subscription options:

The smartwatch should come with subscription options via the use of a sim card. Only this way, the smartwatch can act without phone. Nowadays, 4G LTE subscription options are even provided by some manufacturers. So, the decision should be made after some thinking and analysis.

Battery life:

Good battery life is essential for the success of the device as a phone watch connects to the Cellular network to work independently without a smartphone. The cellular network causes increased usage of battery, so the smartwatch should come with a larger battery.

Conclusion

The Apple Watch Series 5 and the Samsung Galaxy S3 Frontier give tough competition to each other. The Apple Watch is an economical option for the fanboys, while the S3 Frontier’s rotatable bezel is an attractive gimmick. After a deep analysis, we conclude that the Samsung S3 Frontier is the best smartwatch to make calls without a phone.

Frequently Asked Questions

Can standalone watches be paired with smartphones?

Yes, all the watches work primarily by pairing with a smartphone via Bluetooth but they can also be worked without a smartphone in proximity by connecting with the cellular network through SIM.

Can I use my sim card with my smartwatch?

The Apple watches require special data plans. For the rest of the models, you can check the size and carrier compatibility before buying.

Does the 4G have an impact on the battery of the watch?

The battery timings mentioned in the article are for paired usage. 4G LTE usage decreases the battery timing of the watch.