My 3-year-old Android phone still works well, but one hardware shift is forcing me to update

My 3-year-old Samsung Galaxy S23 Ultra still works remarkably well. Despite its age, the Galaxy can handle my everyday tasks with ease.

The display still looks great, and Samsung’s regular software updates ensure I have access to most of the latest and greatest features.

I really have no reason to upgrade. But there’s one major hardware shift that makes my phone feel outdated.

It’s a shift that a software update can’t fix: the move to silicone-carbon batteries. It’s the single biggest reason why I’m strongly considering an upgrade.

My Galaxy S23 Ultra started showing its age

I just never realized it

When I first started using the Galaxy S23 Ultra in 2023, the runtime of its 5,000mAh battery impressed me.

The phone could easily last a full day with moderate or heavy use, with power left to spare. I never had to worry about running out of juice late in the evening or night.

Fast-forward to today, and that same battery life no longer holds up. It just feels adequate — enough to get me through the day.

A heavy day of use, with some wireless Android Auto usage or Google Maps navigation thrown in, is enough to drain the battery by evening.

And that’s despite getting the battery replaced a few months ago, so the drop in runtime isn’t down to wear and tear.

While a dent in its armor, I was still happy using the Galaxy S23 Ultra as my daily driver. That is, until I spent a week with a phone, packing a massive 7,300mAh cell.

I wasn’t ready for this battery upgrade

A week with the OnePlus 15 changed everything

A friend lent me his OnePlus 15 to use for around a week. I did not pay much attention to the phone initially, since my Galaxy S23 Ultra worked fine.

But then, I decided to use it as a daily driver for a few days.

In practice, the OnePlus 15 has similar dimensions to the Galaxy S23 Ultra. But its battery life is on another level entirely.

While my aging Galaxy can just about make it through a day of heavy use, the OnePlus 15 delivers true two-day battery life on moderate use, or 1.5 days on really heavy use.

I did not think Android phones could deliver such good battery life.

If anything, using the OnePlus 15 put an end to my battery anxiety for good. I never once worried about putting the phone on charge before I went to bed or early in the morning.

Even sitting at 30%, I knew it had more than enough juice to make it through half a day.

It’s not like OnePlus is using some super-efficient, power-sipping display or SoC on the OnePlus 15.

It’s due to the difference in battery size, with the phone packing a massive 7,300mAh cell vs. the Galaxy S23 Ultra’s 5,000mAh battery.

So, how can OnePlus fit a battery almost twice as big as the Galaxy S23 Ultra’s 5,000mAh cell into a similarly sized phone? The answer is silicon-carbon battery technology.

I am not going to get into the technical details, but silicon-carbon batteries pack more energy density than traditional lithium-ion cells in the same physical space.

That means a higher capacity battery can fit in the same form factor.

You’d think a bigger battery would mean longer charging times. But that’s not the case with the OnePlus 15.

Thanks to its 80W wired charging, the phone refilled its massive 7,300mAh battery in roughly the same time my Galaxy S23 Ultra takes to top up its much smaller 5,000mAh cell.

In other words, the bigger battery on the OnePlus 15 does not come with a charging time penalty.

This was another reason the OnePlus 15 never gave any battery anxiety.

Irrespective of how much juice was left in the tank, I knew a few minutes on the charger would be enough to last the rest of the day.

A quick 15-minute top-up while I was getting ready in the morning was enough to make it through a full workday.

By comparison, my Galaxy S23 Ultra maxes out at 45W wired charging. Frankly, it never really felt slow in all these years.

After I became used to the OnePlus 15’s superfast charging speeds, it felt like a major downgrade.

This is the upgrade I can’t ignore

Even after three years of use, I had few complaints about the Galaxy S23 Ultra. I was perfectly happy using it as my daily driver — until I tried the OnePlus 15.

More than the faster performance or brighter display, it made me realize that battery technology has silently taken a big leap.

Silicon-carbon batteries can pack in way more capacity than what’s inside my Galaxy S23 Ultra, while also charging ridiculously fast, all without making the phone any bigger.

After using one, I realized there’s simply no way a battery replacement or software update can bridge that gap.

And as I spend more and more time on my phone, battery life has become one of the features I value most.

That’s exactly why this hardware shift is finally pushing me to upgrade. A multi-day battery life upgrade is a leap too good to ignore.

8.5/10

SoC

Qualcomm Snapdragon 8 Elite Gen 5

RAM

12GB / 16GB

Storage

256GB / 512GB

Battery

7,300mAh

The OnePlus 15 brings a massive 7,300mAh battery to the flagship phone table, which when paired with the Qualcomm Snapdragon 8 Elite Gen 5 processor gives it spectacular battery life. Despite the battery size, the phone has a modern design and modest weight, and also showcases OnePlus’s new DetailMax Engine for the camera.