Android 16.2.1 for Teracube 2e 1st Batch Zirconia (SN: 2020)

[Terabot]

NOTE 1 : These builds ONLY WORK for the Teracube 2e 1st batch (SN: 2020) Zirconia, and not 2nd batch (SN:2021). Please read the differences here carefully and install accordingly.
If you are looking for SN:2021 T2e (Emerald), you can find it here.

NOTE 2: All firmwares released for Teracube 2e (2020) & Teracube 2e (2021) don’t pass Play Integrity this includes Android 10/11/12/13/14/15. We’ve explored all options, but implementing Remote Key Provisioning (RKP) a strict requirement for Strong Integrity is simply not feasible for us right now.

NOTE 3: It is expected for the device to stay longer on Teracube logo for the first time after installing the upgrade & The device may respond slow for some time after upgrade, apps are optimising in background. We recommend waiting 15min on idle post upgrade before using it for an optimal experience.

We are thrilled to share our (16.2.1+be19b31) Android 16 QPR2 for Teracube 2e 2020 as it shipped out with Android 10 all the way to Android 16

What’s New?

• March 2026 security patches
• Disable blur effects
• Improvements to battery & perfomance
• Material 3 expressive design updates
• New app pinner to counter A16 aggressive app killing → Settings → Apps → App pinning

Steps to Upgrade:

If you are on 16.0.1+73951f6.zirconia

• First install Updater.apk
• Then download and install the incremental update 16.0.2+ebb5373.zirconia.user
• After successfully updating to 16.0.2, proceed with the steps below to install 16.2.0
  (Otherwise the update will not install)

For everyone else:

1. Download the upgrade zip
   file directly on the phone (or transfer the zip to the phone).
2. Goto Settings > System > Updater (or Teracube Updater)
3. Click top-right 3 dots > Local update or Click on the top-right File icon
4. Tap “Internal storage” and browse to Downloads or wherever you transferred/downloaded the update zip file.
   Note 1 : If Internal storage does not show anything, then reboot the phone.
   Note 2 : Do not download the update to SD card.
   Note 3 : Before you update, make sure you have at least 6GB of free storage and your battery is at least 50% charged. This will help ensure a smooth update process.
5. Select the file and continue the update process.
   Note: If the Updater closes or crashes, then try again.
6. Upgrade process will take a while.
7. Reboot the phone after the updater says “Update installed”.
8. First boot after upgrade can take several minutes.

Do note, after the update, you’ll need to re-enroll your fingerprint and some users have reported that they lose their launcher - icon and widget arrangement. We’d suggest you take a screenshot of your homescreen before performing the update!

Let us know how it went and post your questions/feedback here. Please keep the comments related to this update itself.

If you experience any errors/issues, you can install the original factory software using the automated installer or SP Flash.

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SPFlash Image for 16.2.0 (Zirconia):

16.2.0 Zirconia (2020x)

[trader2019]

This is great! I am actually still using my teracube 2e 2020 as a second phone and I am thrilled it still gets updates! Thanks a lot!

[Maymne]

Flashed this on my Teracube which had been on 15.0.2 last week and everything seemed to go fine - no sdcard wipe, no app loss or other issues. Did lose fingerprints but they added back without major issues.

[Terabot]

There’s a new update available! However, if you are currently on 16.0.1+73951f6.zirconia , you’ll need to take an extra step before updating.

Why the extra step? A patch in Android 16 recovery blocked installation of A-only updates. To ensure you can continue receiving future updates, we’ve created a workaround.

What you need to do:

1. Install the updated Updater.apk
2. You’ll receive an incremental update to 16.0.2+ebb5373.zirconia.user
3. Once on 16.0.2, you can then proceed with the 16.2.0 update

This hotfix ensures your Teracube 2e (2020) - zirconia device will continue to receive future updates seamlessly.

Thanks for your patience and understanding!

[Maymne]

Did run through the upgrade process on my 16.0.1 Zirconia - installed the updater APK, launched the update check, it found 16.0.2, downloaded and started installing it, waited about 30 minutes for the update to finish (took SO much longer than expected), immediately launched the update check, found 16.2.0, waited 10-15 minutes for that one to finish (significantly faster than the 16.0.2 had been) and everything has seemed to be working properly since then. No major new issues seen since updating yet, but it’s not my daily driver so I catch less of the issues quickly than before.

[kaffalo]

Went from 15 to 16.2.0 with manual update. No issues, everything seems to work as it did before. I use Lawnchair so nothing changed with my launcher setup.

[rjf_T2e]

Is it necessary to manually install the new Updater.apk if you are coming from 15.0.2+c235e82.zirconia or can you just go straight to 16.2.0 with the standard installed updater?
(“16.2.0+fd91a35.zirconia.user” is being offered OTA to me in the UK).

[Terabot]

No need to install the new Updater.apk on 15.0.2 but having it wont change anything either

[Pat_2284]

Thank you for going 1st, or at least posting same. I was in the same situation and concur e that this worked without the upgrade package.

[trader2019]

So cool, thanks a lot for this update!!

[Dmitry_Stepanov]

Thank you for keeping up with the updates! So good that you guys are hustling on it!

[Terabot]

New update available!

[Abdiel]

Awesome!

[redearthman74]

I updated my Teracube with the most recent update (showing on my phone as 16.2.1+be19b31) and it has not recharged to 100% capacity since. In fact, it has shut itself down three times while showing 50-55% battery. This battery is relatively fresh and I don’t think it is the problem.

Any ideas?

[Saijin_Naib]

I am checking with the team if any changes were made to charge management/reporting, or anything else that might impact this behavior.

[Maymne]

Mine does that, but it’s because with one of the recent updates the battery settings gave the options for how aggressive did I want the battery health saver to be and I went with (or left it as) fully aggressive and not charging above 60% ever, if memory serves. Phone isn’t within reach right now and not expected to be for a few hours, so…
Anyways, my update to 16.2.1 went fine with no major concerns, just the standard “external sdcard apps don’t appear on a reboot if I don’t wake up the phone quickly enough and the initialization period passes so then I need to reboot the phone again and pay more attention next time” issue that’s been standard since forever. We’ll see if I get motivated enough to try rooting it and seeing if that reboot loop bug got fixed or if it’s still hanging around. At least it’s easy enough to reflash the unmodified bootloader if there’s a non-OTA zip available and so the process of extract/copy to TC2/patch bootloader/copy back/reboot to download mode/flash/reboot to system (or bootloop)/keep or flash back to download mode and flash and reboot back can be completed in about 15 minutes including the still slow (due to unlocked bootloader making reboots to system take an extra 2 minutes, which is weird because my other same-era phone with an unlocked bootloader doesn’t hang there as long) rebooting process.

[Saijin_Naib]

Good point!

The team confirmed that nothing in the recent updates would affect charging behavior, so checking the Charge Limit and the cell health are most likely causes at this point.

[redearthman74]

Charge limiting was not switched on, so unless there is an undocumented limit to the charging, I don’t see why it wouldn’t go to 100% the way it used to. I installed the new battery two years ago now (April 2024) and my initial battery lasted from January 2021 at purchase until then.

I am from a time when you let the battery run all the way out the charge it all the way up - I was assured those days are past and I now charge it when I go to bed.

What is best practice now for how I should be charging my phone and is this likely to vary from one handset to another? (I also have a Nokia 6.2.)

Thank you!

[Maymne]

According to Accubattery, using charge limiter will keep the battery significantly healthier over time and it will tell you how many charge cycles you’re using to charge to each level. I tend to leave that on for most of my Android devices but the specific target varies based on the specific phone’s usage and current battery health, going into a death spiral of burning more capacity as the discharge worsens.