Android tablets without battery

Hi all

After this, I now had the second tablet with a swollen battery.
Now I really want to find a solution. :exploding_head:

I see many posts discussing alternatives. Some with specialized screens (i.e Raspberry Pi), most of which I think are too expensive or to thick. Or using a Switch to only charge the tablet once the battery is < 20% and switch off charging > 80%.

I think the easiest way for me would simply be to find an old Android tablet that works well without battery or at least has a proven method to get it working without a battery.
For the first tablet, I was able to add a resistor and it boots. But now it constantly moans about the battery being -20°C.
The second one I fixed with this method. Tablet starts, but somehow I managed to break the touch screen in the process.

So my question:
Does anyone know of an (old) Android tablet that can be easily be modified to work without a battery ?

Thanks!

A swollen battery can be avoided if it is allowed to discharge. There must be a charge-discharge cycle.

I have an old Nexus 9 plugged in a Wifi socket managed by openHAB.
The tablet runs Termux. A cron job checks if the battery is below 20 or above 80 and tells openHAB to start or stop the current.

https://wiki.termux.com/wiki/Termux-battery-status

Thanks! True, that’s one way to do it and I’ll consider it.
For one of the tablets it’s rather difficult to do that though. I have a multi-usb-charger and it powers the tablet in question + all mobile devices that need charging. I can’t switch off the whole charger.
And I only have one socket that is very exposed, so I can’t add a wifi socket there.

Since I never use the battery in these tablets, I thought maybe someone knows of a device that works equally well without one.

If you use HabPanelViewer, you can have HPV report the battery status to an OH item instead of using CRON to trigger the rule.

Did it happen with two different tablets, or the same tablet with a replacement battery? I’ve anecdotally found that random replacement batteries never last as long as the originals, no matter how much they claim to be OEM.

I’d also be curious to know the brands/models. I’ve had an Amazon Fire HD 10 from 2019 on my wall for about two years, and there’s no sign of the battery swelling.

Yes, two different tablets with the original battery still in place. One was a Samsung Galaxy Tab 4 and the other one a HTC Nexus 9. The batteries were already quite worn as they were in use for years. That’s why I got the tablets for free :grin:

Also still got a Amazon Fire HD up that is still fine. But got that one new about 3 years ago and I assume it’s just a question of time until that battery swells too.

Yeah, those were pretty old tablets so it’s not surprising.

If you do the 20/80 thing with your Fire HD, it should last you a few more years. I have mine mounted with 3M Command strips, so I can see a uniform gap between it and the wall. It’ll be obvious if/when it starts swelling, and it’s easy to remove.

At www.allnet-shop.de, a german online-shop, I ordered this wall mounted android tablet without battery.

Maybe this is what you are looking for?
In my opinion, this is the best way to avoid problems with battery.
There are sizes from 8" up to 32" and some of them can be powered by poe.

I’m just about building a openhab 4-dashboard and setting up the tablet.
So I can’t report experiences yet.

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Thanks a lot for the link. Yes, this looks like something I had in mind! :+1:
Of course the cost is much higher than a second hand Android tablet, at least for a recent Android version. Will check them out, thanks.

Curious about your experience of course. So if you have time, please report back once you’ve tried it :wink:

Since it’s Rockchip, chances of getting Android updates are at circa 0% though, I guess…which would annoy at least me a bit, given the price point.

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