this post was submitted on 19 Aug 2026
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Mildly Interesting

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This is for strictly mildly interesting material. If it's too interesting, it doesn't belong. If it's not interesting, it doesn't belong.

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Explanation:

This is a Samsung tablet from 2014, currently has LineageOS 18.1 (Android 11), the last it can get. Since it's unused I did a little experiment until I find someone who will use it. Today I have found so here is the post.

After charging it to 100%, I disabled Wi-Fi connection, put it on battery saving mode and it's been on for more than 2 months. Battery is still in good condition after all these years I guess. :)

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[–] MrSoup@lemmy.zip 52 points 1 week ago (4 children)

I don't understand the graph. Why does it have spikes up and down and why, despite being at 13%, it shows roughly 75%?

[–] arandomthought@sh.itjust.works 45 points 1 week ago

Hey, battery technician here. You see, what happened here is that the hungry little caterpillar has entered the digital age and I don't know what the hell is going on here.

[–] muhyb@programming.dev 18 points 1 week ago (2 children)

It probably cannot measure correctly because this is an unexpected usage. Correct place is the bottom of it obviously. The screenshot just coincided with the upper side of the spike.

[–] Valmond@lemmy.dbzer0.com 12 points 1 week ago (1 children)

So it started out at 50%?

This doesn't make any sense for me, except if it was plugged in and the battery is dying over time 😋

[–] muhyb@programming.dev 4 points 1 week ago (1 children)

I think it cannot show the whole graph, maybe the only one month part is here.

[–] Valmond@lemmy.dbzer0.com 11 points 1 week ago

That still doesn't make any sense IMO.

[–] RogueBanana@piefed.zip 9 points 1 week ago

I think its more of a sensor issue. Not too surprising given the age.

[–] abigscaryhobo@lemmy.world 5 points 1 week ago

My guess (I don't know if this is actually right) is that the battery is showing a lower charge while under load. So when it wakes up to do it's little periodic checks/activity (could be trying to fetch updates, could be scans, could be cleanup, idk) it draws additional power and the old battery can only support that load for so long.

Explanation based on theory as I understand it: Using an analogy, batteries aren't a cup full of electricity that just gets sipped or dumped, they're closer to a water balloon with a little valve. The system may only use a little water at a time, but the "battery full" percent is the measure of how much pressure is in the balloon to push the water out. So when the valve is mostly closed (phone is idling) the pressure is pretty normal, slowly dropping. But as batteries age when you open the valve further you start to realize the battery can't actually push out the pressure you need (the balloon has stretched out). The pressure drops, to the levels it would be at if the balloon was brand new, but almost drained. The valve closes more as the device demands less power, and it seems like the expected pressure returns to normal, because the balloon can handle that lower pressure demand.

In short "New battery almost dead under load = old battery mostly charged but under load" but "new battery charged with no load = old battery charged with no load" which is why you see the slingshotting on the battery graph.

[–] Onomatopoeia@lemmy.cafe 17 points 1 week ago* (last edited 1 week ago) (2 children)

Wow, 2 months? How big is the battery!?

Looks like the current version of Accubattery works on Android 7!

If you install it and then do a full charge cycle (15%-100%) it can determine battery health by how much power is required for that charge cycle.

It's not perfect, but I've found it pretty effective at predicting my run times over the last 10 years/half a dozen different phones.

I'd even upgrade this from mildly interesting to interesting!

[–] Axolotl_cpp@feddit.it 6 points 1 week ago* (last edited 1 week ago) (1 children)

It's not that surrpisingly, they doesn't use it at all and the rom is Lineage;

i once remove all google bullshit from a shitty 80€ phone and used it as server for a discord bot, it would last roughly a week per charge, it also had a version of android that was way too heavy for such a cheap phone, if i had installed Lineage and an older version (android 7?) It would've lasted way more probably

[–] muhyb@programming.dev 4 points 1 week ago

Yeah, not having anything Google related surely increase the battery health. Also mental health.

[–] muhyb@programming.dev 3 points 1 week ago (1 children)

Apparently 8220 mAh o.0

Don't know the size though.

Actually maybe can try this before handing the tablet over. Though it would take another 2 months so maybe not . :)

[–] Onomatopoeia@lemmy.cafe 2 points 1 week ago

Decently sized, impressive runtime for that capacity.

[–] Zomg@piefed.world 9 points 1 week ago

Yo I think your tablet is sick or something

[–] logan_hero@lemmy.dbzer0.com 3 points 1 week ago

Damn new tablets get good battery life. Older model ones the only can go to 1 month standby settings shows battery depletion graph

[–] thenoirwolfess@fedinsfw.app 3 points 1 week ago

I placed on charge my iPod Touch 2G and it awoke, had been surviving on its old ass battery for about 45 days

[–] pewpew@feddit.it 3 points 1 week ago

Schrödinger battery

[–] gon@lemmy.dbzer0.com 3 points 1 week ago

Impressive!!!!!!

[–] lyrial@anarchist.nexus 2 points 1 week ago (1 children)

Reminds me of how I recently found an old android tablet/e-reader combo I found the other day. It is from 2010 and runs a rooted Android 2.2. The battery doesn't seem to work at all, but it does turn on and fully work. The touch screen isn't even capacitive. I connected it to a public wifi and it works, but no site will load via the browser. I'm not sure what to do with it, but having a functional e-reader will be nice.

[–] muhyb@programming.dev 1 points 1 week ago

If it's functional as a reader that's fine I think. You can also turn it into a some kind of server though Android 2.2 is really old and you won't likely to find apps from F-Droid for it.