this post was submitted on 13 Jul 2025
87 points (96.8% liked)

Ask Lemmy

33281 readers
1807 users here now

A Fediverse community for open-ended, thought provoking questions


Rules: (interactive)


1) Be nice and; have funDoxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them


2) All posts must end with a '?'This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?


3) No spamPlease do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.


4) NSFW is okay, within reasonJust remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either !asklemmyafterdark@lemmy.world or !asklemmynsfw@lemmynsfw.com. NSFW comments should be restricted to posts tagged [NSFW].


5) This is not a support community.
It is not a place for 'how do I?', type questions. If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email info@lemmy.world. For other questions check our partnered communities list, or use the search function.


6) No US Politics.
Please don't post about current US Politics. If you need to do this, try !politicaldiscussion@lemmy.world or !askusa@discuss.online


Reminder: The terms of service apply here too.

Partnered Communities:

Tech Support

No Stupid Questions

You Should Know

Reddit

Jokes

Ask Ouija


Logo design credit goes to: tubbadu


founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] Ilovethebomb@sh.itjust.works 6 points 20 hours ago (11 children)

You can get a voltage sensor that is accurate to three decimal points for literal cents, so yes, your phone does know how much energy is left in the battery. It also has current sensors, so knows how much energy is being used.

[–] j4k3@lemmy.world 3 points 19 hours ago (3 children)

It does not know the capacity loss of the cell over time. That is why you should let the battery go completely dead and then charge it to max capacity as this will recalibrate the coulomb meter on the battery manager - batman

[–] Ilovethebomb@sh.itjust.works 2 points 19 hours ago (1 children)

My understanding is that happens constantly as the battery is charged and discharged.

[–] j4k3@lemmy.world 3 points 19 hours ago

It tries but the value is floating until it actually has a full charge cycle. There is no way to know what the entire voltage range is. You're getting into how efficient the chemistry is over time and that is impossible to measure. It can be estimated, but that is all theoretical and not real. When the battery is fully discharged, the time, temperature, and current can be used to determine Coulombs and that is the actual energy capacity.

I'm not an expert, but I have built many circuits. My main experience here is in reverse engineering some gaming hardware that had an advanced battery management chip from Diode Semiconductors. That had such a Coulomb battery meter. The board was a 3 layer PCB and I took that as a challenge. The batman chip was also a small ball grid array (pins are inaccessible on the back side. I didn't have xrays when I did the first trace of all pins, so I had to fully understand the chip to trace all connections only using the vias. I think I have a chip or two in parts drawers that do the same thing, but I never built anything with them, or at least haven't yet.

load more comments (1 replies)
load more comments (8 replies)