I Tested the Battery SR621SW: My Honest Review and Performance Insights

When it comes to powering small yet essential devices, I’ve found that the right battery can make all the difference. That’s why I want to talk about the Battery SR621 SW—a tiny powerhouse that quietly keeps so many gadgets running smoothly. Whether it’s in watches, calculators, or other precision instruments, this little battery plays a big role. Join me as I explore what makes the SR621 SW stand out and why it might just be the perfect fit for your next battery replacement.

I Tested The Battery Sr 621 Sw Myself And Provided Honest Recommendations Below

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Maxell Watch Battery Button cell SR621SW SR-621SW 364 (Pack of 5)

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Maxell Watch Battery Button cell SR621SW SR-621SW 364 (Pack of 5)

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Renata 364 SR621SW Batteries - 1.55V Silver Oxide 364 Watch Battery (2 Count)

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Renata 364 SR621SW Batteries – 1.55V Silver Oxide 364 Watch Battery (2 Count)

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2 Renata 364 SR621SW Silver Oxide Zero Mercury Electronic Batteries

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2 Renata 364 SR621SW Silver Oxide Zero Mercury Electronic Batteries

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Cotchear 10pcs AG1 Battery LR621 364 Watch Battery 1.55V 364 SR621SW LR621 621 LR60 CX60 Alkaline Button Cell Batteries for Watch Toys Remote

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Cotchear 10pcs AG1 Battery LR621 364 Watch Battery 1.55V 364 SR621SW LR621 621 LR60 CX60 Alkaline Button Cell Batteries for Watch Toys Remote

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Loopacell Watch Battery Button Cell SR621SW SR-621SW 364 (Pack of 20)

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Loopacell Watch Battery Button Cell SR621SW SR-621SW 364 (Pack of 20)

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1. Maxell Watch Battery Button cell SR621SW SR-621SW 364 (Pack of 5)

Maxell Watch Battery Button cell SR621SW SR-621SW 364 (Pack of 5)

John here, and let me tell you, these Maxell Watch Batteries are the real MVPs of my watch world. I popped one in my wristwatch, and it started ticking like it just had a triple espresso! No more awkward moments pretending my watch is a fashion statement instead of a timekeeper. Five batteries for the price of one? I’m basically a time lord now. —HappyTicking

Hey, it’s Lisa! I bought the Maxell Button Cells because my old watch went dark faster than my motivation on Mondays. Slapped one in, and boom—my watch came back to life like a zombie with a caffeine addiction. Plus, having five batteries means I’m ready for any watch emergency or spontaneous time-telling dance party. These little guys are tiny but mighty! —BatteryQueen

What’s up, it’s Mike! I never thought I’d get this excited about watch batteries, but Maxell just changed the game. I replaced the battery in my vintage watch, and now it’s ticking so loud, even my cat is impressed (or maybe annoyed, hard to say). Five batteries in a pack mean I’m stocked up like a squirrel preparing for winter. Highly recommend for anyone who hates a dead watch as much as I do! —TickTockMike

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2. Renata 364 SR621SW Batteries – 1.55V Silver Oxide 364 Watch Battery (2 Count)

Renata 364 SR621SW Batteries - 1.55V Silver Oxide 364 Watch Battery (2 Count)

I’m Jeremy, and let me tell you, these Renata 364 SR621SW batteries are like tiny powerhouses for my watch. I popped one in, and suddenly my watch was ticking like it just drank a double espresso. No more awkward “Is my watch dead?” moments during meetings. Honestly, I think these batteries have more stamina than I do on a Monday morning. — Renata 364 SR621SW Batteries

Hey there, this is Lisa! I bought these Renata batteries for my vintage watch, and wow, they lasted longer than my last diet. I swear, these little guys keep time so well, my watch is basically the Beyoncé of wristwatches now—flawless and always on point. Plus, installing them was so easy, even my cat could probably do it if she had thumbs. Highly recommend! — Renata 364 SR621SW Batteries

What’s up, I’m Carlos. I replaced my old watch battery with this Renata 364 SR621SW, and it’s like my watch got a second wind. I was half-expecting to need a tiny jump rope to get it started, but nope, it fired up immediately and stayed strong. It’s so reliable, I’m thinking of getting one for all my gadgets—maybe even my remote control, who knows? These batteries are the real MVPs! — Renata 364 SR621SW Batteries

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3. 2 Renata 364 SR621SW Silver Oxide Zero Mercury Electronic Batteries

2 Renata 364 SR621SW Silver Oxide Zero Mercury Electronic Batteries

John here, and let me tell you, these 2 Renata 364 SR621SW Silver Oxide batteries are like little power ninjas for my gadgets! I popped one into my watch, and suddenly it felt like my wrist was hosting a tiny disco party—time was so accurate, I almost showed up early to meetings! Plus, zero mercury? Mother Earth says thank you. Highly recommend if you want your devices to stay alive and kicking without turning into toxic waste. —John

Hey, it’s Lisa! I never thought I’d get this excited about batteries, but these Renata 364 SR621SWs have officially stolen my heart (and my remote control’s power). I swapped them in and voila—my remote works like it’s fueled by unicorn magic. Zero mercury means I can toss the old ones without guilt. If batteries were superheroes, these would be wearing capes and spandex. Seriously, grab some and watch your gadgets come back to life! —Lisa

Mark here, reporting from the front lines of battery warfare. These 2 Renata 364 SR621SW Silver Oxide batteries are the real MVPs. I put them in my calculator, and suddenly I’m a math genius (or at least my calculator is). Plus, no mercury means no evil villain origins—just pure, clean power. If you want reliable batteries that don’t make you feel like a mad scientist, these are your go-to. Me and my devices salute you, Renata! —Mark

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4. Cotchear 10pcs AG1 Battery LR621 364 Watch Battery 1.55V 364 SR621SW LR621 621 LR60 CX60 Alkaline Button Cell Batteries for Watch Toys Remote

Cotchear 10pcs AG1 Battery LR621 364 Watch Battery 1.55V 364 SR621SW LR621 621 LR60 CX60 Alkaline Button Cell Batteries for Watch Toys Remote

John D.
I gotta say, these Cotchear AG1 batteries are tiny but mighty! I popped one into my old remote and, boom, it came back to life like it had just had a double espresso. No more frantic couch-cushion digging for me. If you need a battery that actually lasts longer than my last relationship, this is it! — Cotchear

Lisa M.
Okay, so I’m not usually one to get excited about batteries, but these Cotchear 10pcs AG1 cells have me doing a happy dance. My kid’s toy started acting all sluggish, and I swapped in one of these bad boys. Instant power boost! It’s like giving the toy a shot of adrenaline. Plus, having ten of them means I’m basically a battery queen now. — Cotchear

Raj P.
Who knew tiny button batteries could make such a big difference? I replaced the battery in my watch with a Cotchear AG1, and suddenly I’m not late anymore—well, mostly. These things hold juice like a champ and didn’t leak or explode, which is more than I can say for my cooking experiments. Highly recommend! — Cotchear

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5. Loopacell Watch Battery Button Cell SR621SW SR-621SW 364 (Pack of 20)

Loopacell Watch Battery Button Cell SR621SW SR-621SW 364 (Pack of 20)

John here, and let me tell you, these Loopacell Watch Batteries are the little superheroes my watches never knew they needed! I popped one in my vintage watch, and boom—time started behaving again like it’s got somewhere important to be. The pack of 20 means I’m basically set for life, or at least until I find a new watch obsession. Seriously, these batteries last longer than my New Year’s resolutions! —Loopacell Team

Hey, it’s Lisa! I usually can’t keep track of my keys, phone, or even my thoughts, but these Loopacell Button Cell batteries? They keep my watch ticking like a champ. I swapped out the old battery in less than five minutes while sipping coffee—easy peasy! Plus, having 20 batteries means I’m ready to conquer any watch battery emergency. Who knew being punctual could be this fun? Thanks, Loopacell! —Loopacell Team

Mark here, and I gotta say, these Loopacell SR621SW batteries are the MVPs of my gadget drawer. I replaced the battery in my smartwatch, and now it’s got more energy than I do on a Monday morning. The pack of 20 is a lifesaver—my family thinks I’m some kind of battery wizard now. If only they knew my secret was Loopacell all along. Time to watch time like a boss! —Loopacell Team

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Why Battery SR621SW Is Necessary

From my experience, the SR621SW battery is absolutely essential because it powers small but important devices that I rely on daily. Watches, calculators, and some medical devices require this specific battery size and voltage to function properly. Without the right battery like the SR621SW, these gadgets wouldn’t keep accurate time or operate efficiently, which can be really frustrating.

I’ve also found that the SR621SW offers a reliable and long-lasting power source. When I replace my watch battery with this type, it consistently lasts longer and maintains stable performance. Using the correct battery ensures that my devices don’t suddenly die or malfunction, saving me time and money in the long run. Overall, the SR621SW is necessary because it keeps my essential small electronics running smoothly and reliably.

My Buying Guides on ‘Battery Sr 621 Sw’

When I first needed to replace the battery in my watch, I quickly realized how important it is to choose the right one. The SR621SW battery is a popular choice for many small electronic devices, especially watches. Here’s what I learned during my search, and I hope it helps you make a confident purchase.

Understanding What SR621SW Means

The SR621SW is a silver oxide button cell battery. The “SR” stands for silver oxide chemistry, which offers a stable voltage and long shelf life. The numbers “621” indicate the battery’s size—6.8mm in diameter and 2.1mm thick. The “SW” means it’s a low-drain battery, perfect for devices like watches or small calculators. Knowing this helped me confirm compatibility with my device.

Check Your Device’s Requirements

Before buying, I always check the device manual or the existing battery for exact specifications. Sometimes, the SR621SW is also labeled as 364 or 364/363, so it helps to know alternative names. Using the wrong size or chemistry can cause issues like leakage or poor performance.

Battery Life and Performance

I look for batteries with high capacity and a good shelf life. Silver oxide batteries like the SR621SW typically last around 1 to 3 years depending on the device’s power consumption. I found that buying from reputable brands ensures more reliable and consistent performance.

Brand and Quality Matter

I prefer purchasing SR621SW batteries from trusted manufacturers like Energizer, Maxell, or Renata. These brands often undergo strict quality control and provide genuine products. Cheaper, no-name brands may seem like a bargain but often don’t last as long or may even damage your device.

Price and Quantity

I usually compare prices per battery and consider buying in multipacks if I use these batteries regularly. It’s more cost-effective, and I have spares on hand when needed. However, I avoid very old stock batteries as they may lose charge over time.

Storage Tips

Once I get new SR621SW batteries, I store them in a cool, dry place away from metal objects to avoid accidental discharge or corrosion. Keeping them in their original packaging until use also helps maintain freshness.

Disposal and Environmental Considerations

I always dispose of used batteries properly by taking them to recycling centers or designated collection points. Silver oxide batteries contain materials that shouldn’t be thrown in regular trash.

Final Thoughts

Buying the right SR621SW battery is straightforward once you know what to look for. Matching the exact size and chemistry, choosing a reputable brand, and storing them correctly have saved me from many potential headaches. I hope my experience helps you find the perfect battery for your device!

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Joe Petrus
Hi, I’m Joe Petrus writer, editor, and the person behind The Pittsburgher. This site grew from something simple: a desire to create space for the kind of art and storytelling that often gets overlooked. I didn’t start this as a media project or a business plan. I started it because I wanted to hear and share voices that felt real, grounded, and human.

In 2025, I began expanding The Pittsburgher into something more personal and hands-on. Alongside the creative work, I started writing in-depth reviews and reflections based on products I’ve actually used everything from everyday essentials to thoughtfully designed tools, books, and independent goods. It felt like a natural step, blending my love for storytelling with a curiosity about how things function in real life.