Replace Your Tablet Battery Yourself – How to Save Your Old Device in 20 Minutes!

Sun, 16 Nov 2025 00:00:00 +0000

When Your Tablet Never Leaves the Charger

Sound familiar? Your tablet used to be great, but now the battery barely lasts a few hours. Maybe you use it for your Smart Home Dashboard in Home Assistant or for other purposes – but being permanently tethered to a cable is simply annoying.

Most people think: “Time for a new device.” But wait! These devices are far too good to throw away. In this article I’ll show you how to breathe new life into your tablet with a new battery – and without any special tools!

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Why Repair It Yourself?

Sustainability and Resource Conservation

Every repaired device is a win for the environment. Manufacturing a new tablet consumes enormous resources – raw materials, energy, water. A new battery for €20–30 and 20 minutes of your time can extend the device’s life by years.

Save Money

A new tablet can easily cost several hundred euros. A replacement battery? About €20–30. The math is simple!

It’s Fun!

Honestly: there’s a really great feeling when the device works again after the repair. In the video you can watch every step live alongside me!

My Example: Samsung Galaxy Tab S3

For my Smart Home Dashboard I use a Samsung Galaxy Tab S3. It’s a bit older, but still perfect for Home Assistant. The battery, however, was completely done – the tablet only lasted a few hours.

Spoiler: After the battery replacement it now runs for a whole week again! 🎉

What You Need

Tools (no special equipment!)

Hair dryer (yes, really – your regular hair dryer!)
Suction cup or suction cup clamp (available at any hardware store)
Plastic spatula or an old credit/loyalty card
Small screwdriver (Phillips head)
Optional: Plastic opening tools (available online for a few euros)

Materials

Replacement battery matching your tablet model
Optional: Replacement adhesive strips for the housing

Important note on buying the battery:

⚠️ Do NOT buy the cheapest battery you find online!

Make sure to look for:

✅ Reputable distributors
✅ Good ratings and reviews
✅ Brand manufacturers or certified replacements

Why? Low-quality lithium-ion batteries don’t just perform poorly – in the worst case they can catch fire. Safety first! I cover this in detail in the video.

Step-by-Step Guide

Step 1: Warm Up the Housing with the Hair Dryer

The first step is heating the adhesive between the housing and the display. Without this step you won’t be able to get into the device.

My recommendation:

Lowest airflow setting
Maximum heat
About 2 minutes warming the entire housing
One corner more intensively (that’s where you want to open it first)

Temperature check: If you can just barely touch the tablet without burning yourself, it’s perfect!

In the video you can see exactly how long I hold the hair dryer and how!

Step 2: Open the Housing with a Suction Cup

Now comes the exciting part. Using a suction cup or suction cup clamp you carefully pull the housing apart.

Two options:

Option A: Suction cup clamp (the one I use)

Place it on the warmed corner
Carefully tighten until a gap appears
No force – just warm it up again if needed!

Option B: Two simple suction cups

One on the front, one on the back
Carefully pull apart with your hands
Again: patience matters more than strength

You’ll see in the video: In my case the housing pops open after just a few turns!

Step 3: Fully Open the Housing

Once the first gap appears, grab a plastic spatula or an old credit card.

Important:

⚠️ Do NOT use metal tools!
✅ Plastic only – that way you won’t scratch anything
✅ Don’t go too deep into the device
✅ Work your way completely around the device

If it doesn’t slide smoothly somewhere? Just warm up that spot with the hair dryer again. In the video I show you the right technique!

Step 4: Watch Out for Cables!

On my Samsung tablet: The back panel has no cabling – just lift it off.

On other tablets: Carefully check whether ribbon cables connect the back panel to the circuit board! Otherwise you’ll tear something off when opening it.

Step 5: Remove the Battery

Now it gets technical – but don’t worry, it’s easier than it looks!

On my tablet:

Loosen a few screws securing the battery
Carefully disconnect the ribbon cable
Gently lift the contact clips with a small screwdriver
Pull out the cable

In the video you can see every single step in close-up – I show you exactly where each cable sits!

Step 6: Remove the Old Battery

The battery is usually still secured with some adhesive tape. Carefully lift it and remove it from the housing.

Note: Don’t just throw the old battery in the trash! Batteries belong at the recycling center or at the collection point in an electronics store.

Step 7: Install the New Battery

The new battery goes in exactly the same spot.

Connection order:

Place the battery in the housing
Reconnect the ribbon cable
Press the contacts firmly
Screw the screws back in

In the video I show you what to pay attention to when connecting the cables!

Step 8: Function Test BEFORE Closing!

Important: Test that everything works BEFORE you close the housing!

What I test:

✅ Tablet can be switched on
✅ Display works
✅ Buttons respond
✅ Speakers work
✅ Battery charges (plug in the charging cable!)

In the video you’ll see the exciting moment: Does it turn on? 😊

Step 9: Calibrate the Battery

Before closing the housing, it’s a good idea to:

Charge the battery fully (100%)
Let the tablet drain completely without charging in between

Why? This way the operating system learns the actual capacity and can display accurate remaining runtime again.

Step 10: Close the Housing

Now comes the final step!

Option A: Use the remaining adhesion (what I do)

The old adhesive often still holds well enough
Simply press the back panel on and you’re done
⚠️ The device is then no longer waterproof

Option B: New adhesive strip

Remove the old adhesive
Apply a new adhesive strip (order it together with the battery!)
Good sealing again

For my Smart Home Dashboard, Option A is perfectly sufficient!

The Result: Mission Accomplished! 🎉

In just 20 minutes: My Samsung Tab runs for a whole week again, just from a new battery!

The tablet is back to being:

✅ Usable permanently as a dashboard
✅ Usable without constant recharging
✅ Ready for years more of service

Common Problems and Solutions

“The housing won’t open”

Solution: Heat it up again! Better to use the hair dryer for 30 seconds longer than to use force.

“I’m afraid of breaking something”

Solution: In the video you can see every move. Take your time and work calmly. Most damage happens from rushing!

“Which battery is the right one?”

Solution:

The exact model number is printed on the old battery
Search for that number at reputable shops
Read the reviews!

“The cable won’t connect”

Solution: Some connectors are a bit fiddly. In the video I show you how I handled the tricky connector on mine – it took me a while too!

Safety Notes

During the Repair

⚠️ Never work while connected to power!
⚠️ Do not damage the battery (risk of short circuit/fire!)
⚠️ Choose a well-ventilated room
⚠️ Keep children and pets away

After the Repair

✅ Supervise the first charging cycle
✅ The tablet getting warm is normal
✅ If you see smoke, disconnect from power immediately!

Why This Fits Perfectly with “Using Tech Smartly”

This channel is called “Smart Home? But Secure!” for a reason – and smart means:

Conserving resources instead of throwing things away
Taking action yourself instead of buying everything new
Understanding and mastering technology

A repaired tablet for a Smart Home Dashboard is the perfect example: Old meets Smart!

Your Repair Project?

Write to me in the comments:

Have you ever replaced a tablet or smartphone battery yourself?
What was your experience?
Do you also use your tablet for Smart Home?
Which device are you considering repairing?

Make sure to watch the video – there you can see every step live and get all the important tips!

More Repair Guides

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Repair Sonoff S20 Smart Plug – the 26 Cent Repair – Permanently fix the unstable WiFi connection on the Sonoff S20 with a capacitor replacement

Upcycling on Smart Home? Sure — But Secure!

Replace Your Tablet Battery Yourself – How to Save Your Old Device in 20 Minutes!

When Your Tablet Never Leaves the Charger

Why Repair It Yourself?

Sustainability and Resource Conservation

Save Money

It’s Fun!

My Example: Samsung Galaxy Tab S3

What You Need

Tools (no special equipment!)

Materials

Step-by-Step Guide

Step 1: Warm Up the Housing with the Hair Dryer

Step 2: Open the Housing with a Suction Cup

Step 3: Fully Open the Housing

Step 4: Watch Out for Cables!

Step 5: Remove the Battery

Step 6: Remove the Old Battery

Step 7: Install the New Battery

Step 8: Function Test BEFORE Closing!

Step 9: Calibrate the Battery

Step 10: Close the Housing

The Result: Mission Accomplished! 🎉

Common Problems and Solutions

“The housing won’t open”

“I’m afraid of breaking something”

“Which battery is the right one?”

“The cable won’t connect”

Safety Notes

During the Repair

After the Repair

Why This Fits Perfectly with “Using Tech Smartly”

Your Repair Project?

More Repair Guides