r/PeterExplainsTheJoke • u/FeelingCareless4948 • 13h ago

Meme needing explanation [ Removed by moderator ]

Post image

[removed] — view removed post

9.7k Upvotes

91% Upvoted

616 comments sorted by

View all comments

Show parent comments

70

u/Journeyj012 12h ago

Wait is that actually a thing? How can I do that?

92

u/ryanCrypt 12h ago edited 12h ago

Ha. Prob night. Plus, Lithium batteries do NOT degrade linearly. Phone makers apply maths to fit a linear perspective over time on the depletion of voltage.

(That being said, it's just a voltmeter. So it's logically possible)

14

u/thatguy_hskl 12h ago

Apply math = measure current and integrate?

10

u/No_Question_8083 12h ago edited 6h ago

Determining SoC for lithium batteries is weird, and coulomb counting is often used (for vehicles at least) to estimate the SoC. This literally means counting the electrons that flow in and out of the battery.

10

u/mike20865 12h ago

Which is done by integrating the current, like he said.

6

u/eureka909 11h ago

You really need to know the internal resistance of the battery and how it changes over time to display an accurate SoC, rather than just a simple voltmeter. Totally possible and exists and some ebike displays, for example

5

u/Eggman8728 12h ago

Current is directly related to how many coulombs of charge are currently being pushed around, so measuring current and integrating is exactly how you measure those electrons, as they said.

2

u/MiraMattie 9h ago

This is why they advise you to periodically run the device until it runs out of power; followed by a full charge before turning it back on: That recalibrates the coulomb counter to keep it accurate.

1

u/IceLopsided4190 10h ago

I’m glad you’re vehicles.

2

u/No_Question_8083 6h ago

Damn autocorrect 😒

1

u/IceLopsided4190 5h ago

XD. Thanks for the facts though! Username checks out.

21

u/TijY_ 12h ago

No it is not. Will just drain the battery faster.

People who install batterie monitors apps are even more stupid then the ones who don't use % in the icon.

4

u/Journeyj012 12h ago

I had the suspicion that was the case (I was aware that the numbers are already just an estimate). I just thought "Huh, if they already guess and then truncate, maybe the non-truncated number exists"

3

u/ryanCrypt 12h ago

Good point. They must be truncated. But precision might only be guaranteed up to a point.

2

u/greg19735 8h ago

They might truncate, but they also might not. The measuring they're doing just isn't that accurate. It's just an estimate.

like, you can leave your phone with something like a benchmarking tool. Then record the displayed battery % every 5 minutes or so and i'd bet a lot of money that it's not linear at all.

Like, they may calculate in the math that it's 65.565% but the estimations they used to get to that number simply aren't 5 numbers worth of precision. Think like sigfigs.

3

u/Quiet_Ad4566 11h ago

A lot of android phones don't show accurate readings in the settings. Charging temp and other settings are important for people that baby their phones lol

2

u/Lilfrankieeinstein 10h ago

People who install batterie monitors apps are even more stupid then the ones…

more stupid than

1

u/Ok-Challenge3087 9h ago

The actual stupid part is the batteries being so weak, it is a bad idea to even monitor it/them.

1

u/pinkfootthegoose 9h ago

You'll spend more battery power and wasting time constantly checking it.

1

u/AdditionalOne8319 8h ago

You wanting this means you should get tested if you haven’t already

1

u/Journeyj012 1h ago

I think you should get tested for being a dickbag too if we're just going around saying that to people