Closed Test

Online Battery Closed Test Guide

Last updated: October 22, 2026

Welcome

Thank you for testing Online Battery. Please stay in the test for at least 14 days and open the app every few days: Google only releases the app publicly after 12 or more testers have stayed opted in for 14 days in a row.

Online Battery is for Android phones and tablets that stay on a charger 24/7, such as old phones used as IP cameras, home servers or smart-home bridges. It watches the battery level and temperature and switches a smart plug on your Wi-Fi to keep the battery between 40% and 70% (adjustable), and switches the plug off if the battery gets too warm (32 °C by default).

You don't need a smart plug to take part. A simulated plug lets you try everything without hardware. If you own a TP-Link Tapo, a Shelly or a Home Assistant switch, testing with it is especially valuable.

What we'd like from you:

Install the app and try the parts that apply to you (the checklist below helps).
Keep it installed and stay opted in for at least 14 days.
Tell us what breaks, confuses you or could be better.

Join and install

You need an Android phone or tablet with Android 7.0 or newer and the Google account you use in the Play Store.

1
Join the tester group with that Google account.
Join the tester group: link added when the test opens
2
Open the opt-in page and tap Become a tester.
Open the opt-in page: link added when the test opens
3
Install Online Battery from the Play Store link on that page. It can take a few minutes after joining before the Play Store shows it.
4
Stay opted in for at least 14 days. Leaving and rejoining restarts your 14 days.

If the Play Store says the app isn't available, check that the phone is signed in to the same Google account you used to join, then try again a little later.

First start

The first screen asks how you want to set up the app:

Internal Tester Mode

When: you have no smart plug, or want to explore first.

Uses the simulated plug. The Dashboard shows (Simulated Mode).

Standard Setup

When: you have a Tapo, Shelly or Home Assistant switch.

Walks you through connecting your plug. In the plug list you can still pick Simulated Plug.

You can switch later: on the Dashboard, open Setup & Tester Walkthrough and tap Launch.

Then:

Allow notifications when asked. Monitoring runs as a background service with a permanent notification; without the permission it does not start.
Set up background reliability. Many phone makers stop background apps. The setup and the Dashboard have an OEM Setup Guide (Xiaomi, Samsung, Huawei, etc.) with the exact settings for your brand. Please follow it, otherwise monitoring may stop after a while.
For a real plug: the phone and the plug must be on the same Wi-Fi (not a guest network). Reserve the plug's IP address in your router so it doesn't change. For Tapo, first enable Third-Party Compatibility in the Tapo app. Use Test connection before Save & Connect.

Things to try

Tick off what you tried; anything that didn't work as described is worth a report.

Your ticks on this page are saved only in this browser on this device, and only for as long as you keep its browsing data. Clearing the site's data, or using a private window, removes them, and they don't carry over to your phone or another browser. They never leave your device: we don't collect, see or store which items you tick.

0 items ticked

With the simulated plug

On the Dashboard, open Advanced Diagnostics and switch the plug with Turn On / Turn Off.
Use Thermal test mode to raise the battery temperature past the limit. The plug should switch off and a warning should appear; after cooling below the limit minus 2 °C, normal charging rules apply again.
Pull down the notification shade: the monitoring notification shows temperature and plug state.

With a real plug (Tapo, Shelly or Home Assistant)

Turn the plug on and off from the Dashboard and check it really switches.
Change Start charging / Stop charging so the current level is outside the range, and watch the plug follow (within about a minute).
Leave the phone alone for a few hours with the screen off. Does the plug still switch at the limits?

For everyone

Restart the phone. Monitoring should come back by itself if it was running.
Tap Stop monitoring, close and reopen the app: it should stay stopped until you tap Start continuous monitoring.
After a day or two, look at Insights (charge history and temperature).

Fleet Monitoring (free for testers)

Please don't subscribe through Google Play: test purchases are charged for real. Use the promo code instead.

Fleet Monitoring is the optional paid feature: it emails you when a device stops reporting, overheats, loses its smart plug, or comes back online.

On the Dashboard, tap the Fleet Monitoring & Dead-Man's Switch card.
Enter an email address you read as the alert email.
Under Have a Promo Code?, enter CLOSEDBETA and tap Redeem. This activates Fleet Monitoring for about a month on this device, with no payment.

Then try (these ticks are saved the same way as above):

You receive an activation email.
Switch the phone off (or turn off its Wi-Fi) for 45 minutes: an offline alert should arrive after about 40 minutes, and a "back online" email once it reconnects.
With the simulated plug, a Thermal test mode overheat also triggers an overheat alert email.

The code works once per device. Emails can land in spam; please tell us if they do.

Sending feedback

Email support@onlinebattery.app, use the support form, or use private feedback on the app's Play Store page (testers see this option instead of public reviews). Short notes are fine; praise and "this was confusing" are useful too.

For a problem, please include:

Phone model and Android version
Plug type (Tapo model, Shelly generation, Home Assistant, or simulated plug)
What you did, what you expected, and what happened instead
A screenshot or screen recording, if you can

Never send your plug passwords, Tapo account password or Home Assistant token.

Your data and leaving the test

There is no account, no ads and no analytics. Without Fleet Monitoring, your battery data stays on the phone; the only outside contact is an anonymous subscription check with RevenueCat. Plug addresses and passwords never leave your phone.

With Fleet Monitoring, the server stores your alert email (encrypted), your device ID (the phone's Android ID), the optional device name, and the latest battery level and plug state. Battery temperature is used for alerts but not stored. Details: privacy policy.

To delete it:

In the app: Fleet Monitoring → Delete My Data from Cloud (while online).
Without the device: the data deletion form, with your alert email and device ID.
Automatically: 30 days after the device stops reporting, and at the latest 48 hours after your promo period ends.

To leave the test after the 14 days, uninstall the app and tap Leave the program on the opt-in page. Thank you for helping!