Table of contents

Introduction

Often in reviews, we see comparisons between big brands or even models of the same brand, so it is easy to find articles that compare Apple smartwatches vs. Garmin, Coros, or Casio, and it would be easy to do one of those as well.

But in this article, we will do something different. I want to highlight the different ways you can use the same watch and explain why it may make sense to do so. We will use the Garmin Instinct 2 Solar for this.

In Olden Times

Back in the day when watches were first invented, they could do one thing. They could tell time, and often even that was done poorly. So things were simple, and there was only one way to use your watch. Gradually, as time went by, watches became more elaborate, and complications started appearing.

So a date function was added, then a chronograph complication was added, and eventually GMT watches appeared that allowed people to track a second timezone if they wanted or even track daylight saving time in their own timezone.

Things went completely crazy when digital watches were introduced because of the flexibility of the LCD display. So now we can buy a simple digital watch that supports a perpetual calendar, multiple time zones with separate DST support for each one, multiple alarms, countdown and stopwatch timers with intervals or lap support — and on top of all of this, it can be solar- and potentially radio- or Bluetooth-calibrated for less than $100.

The New Shiny

When smartwatches were introduced, they took all that digital watches could do and evolved them to a different scale. You can do all of the above and much, much more. So the complexity has increased exponentially, and each new feature only adds to this.

Where there used to be only one way to use your watch, you can now pick from the plethora of features your watch supports and use them as you see fit. I can argue that today it is impossible to use all the features.

Smartwatches with sports profiles have such a large collection of sports profiles that it is impossible to do them all. You will only choose a handful. But this does not apply to sports-related features but to the health-related features and the main watch features as well.

All of this complexity and power, of course, needs to be satisfied by using fast CPUs and large batteries. Where in the past a watch would keep ticking for decades with some maintenance, the modern landscape is filled with obsolete smartwatches that have reached the end of their life because their non-replaceable battery died or their manufacturer stopped supporting them — and without their support, some of their features are disabled.

So one might ask: is there a way to combine the longevity of the past with the flexibility of the present?

This is the topic of this article.

Modes of Operation

The first thing that fails with these sealed, non-repairable devices is the battery. It is a consumable with a limited lifespan; it is supposed to fail after a certain number of recharge cycles, and it does. The second part that fails is the charging port. This is a mechanical component that is continuously connected and disconnected, and eventually it wears out.

The third most common failure is when the manufacturer stops supporting the device. Some devices can operate standalone, and others cannot. With Garmin, we are in luck because all the basic information can be accessed on-device, even though in order to get the full benefit of the supported features, you really need to link it with the Garmin Connect app and friends.

So assuming the third most popular failure mode is not a problem, how can we mitigate the first two and ensure that our device lives as long as possible?

The answer is simple: you preserve battery life as much as possible, and this means running your watch with the absolute minimum you need. Garmin allows us to fine-tune our watches to such an extent that with the Garmin Instinct 2 Solar and full health monitoring on — plus 3-4 training sessions per week — I can get more than 20 days between charges.

If I switch the watch to power-save mode and enable it only for training, plus step tracking and the occasional contactless payment, I get more than 60 days. All of this without any serious exposure to the sun, which means that you can get the same results with the Garmin Instinct 2 without the solar panel.

The Garmin Instinct 3 has even better battery life, and more premium models are even better than the Instinct 3.

All this is great, but so far we have not done much to prolong battery life beyond enabling power-save. Is there anything else we can do?

The answer is yes: we can preserve the charging port by not using it.

Many people think that the solar panel used in models like the Garmin Instinct 2 Solar is a gimmick because you have to be outdoors more than 4 hours per day under strong sun in order for this to make a difference. Not many people are, and even if we were, the sun in Scotland is not strong at all.

But there is another way.

During my experiments with my watches, I discovered that instead of waiting for the sun to make an appearance behind the clouds, you can actually use a desk LED lamp. If it is close enough to the solar panel, then the light intensity is significantly stronger than outdoor sunshine on a bright Mediterranean day — and without the heat.

This means that you can leave your Garmin under the desk lamp overnight, and it will charge right up and be ready to be picked up again in the morning.

In addition to preserving the charging port, this also preserves battery health.

Let’s break down how this works.

Optimizing for Battery Longevity 1

Modern lithium rechargeable batteries start deteriorating after about 300-500 full charge cycles, at which point their capacity is reduced to 80% or even lower.

Let’s see how fast a battery will reach that point. For our comparison, we can use three watches: an Apple Watch that needs daily charging, an average smartwatch that needs to be charged every week, and a Garmin Instinct 2 Solar with its two modes of operation — normal and power-save — that provide battery life of 20 days and 60 days, respectively.

Apple Watch

With daily recharging, an Apple Watch battery will start deteriorating at the 300-day mark — that’s less than a year.

Generic Smartwatch

A generic smartwatch with weekly charging will start deteriorating in $\frac{300}{7} \approx 5$ years — not bad at all.

Garmin Instinct 2 Solar Regular Mode

A Garmin Instinct 2 Solar gives us 20+ days battery life in normal mode operation with heart rate tracking, 4-5 training sessions per week, but not much GPS usage. As such, we will get $\frac{300}{\frac{365}{20}} \approx 16.5$ years out of it. Now we are getting somewhere.

Garmin Instinct 2 Solar Power-Save Mode

With power-save mode, Instinct will give us $\frac{300}{\frac{365}{60}} \approx 49.3 years$. Not bad at all.

Optimizing for Battery Longevity 2

Is there anything else we can do?

Sure, this is where things get really interesting. You see, in the original phrase above about battery charge cycles, the operative word was full charge cycles. This means the battery goes from 100% to 0% and then back.

But most people don’t let their devices go down to 0%; they charge them earlier, so they do partial charges. So what happens if we assume we are charging our watches when the battery is at 75%? This means we are only doing a 0.25 charge. We just need to multiply our previous results by 4.

In this scenario, we have the following results:

Watch	Years for 100% Charge	Years for 25% Charge
Apple Watch	0.82	3.28
Generic smartwatch	5	20
Garmin Instinct 2 Solar regular mode	16.43	65.75
Garmin Instinct 2 Solar power-save mode	49.31	197.24

And that is how we take a device with a known fixed lifespan and optimize it to be usable for way longer than expected.

At this point, I would like to point out that the Garmin Instinct numbers can also be achieved without the solar panel, but in this case, the charging port will eventually wear out long before the battery does.

Conclusion

The tl;dr is: if you have a Garmin Instinct 2 Solar, charge it using the solar panel under a desk lamp every 15 days, and the battery will last several lifetimes and your charging port will be in pristine condition for several decades.