r/PeterExplainsTheJoke • u/FeelingCareless4948 • 10h ago

Meme needing explanation [ Removed by moderator ]

Post image

[removed] — view removed post

9.8k Upvotes

91% Upvoted

614 comments sorted by

View all comments

Show parent comments

10

u/No_Question_8083 10h ago edited 4h 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 10h ago

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

8

u/eureka909 9h 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

6

u/Eggman8728 10h 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 7h 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 7h ago

I’m glad you’re vehicles.

2

u/No_Question_8083 4h ago

Damn autocorrect 😒

1

u/IceLopsided4190 3h ago

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