why would a fuse be battery powered ? - Page 1
Forum section: electronics / projects

author: 3roomlab
author_rank: Frequent Contributor
timestamp: November 27, 2023, 02:17:27 am
content: I am obviously not an expert herebut why would a fuse (or this fuse in particular) be battery powered ?any ideas ?some search reveals that owners will be prompted to replace the fusemunro live teardown actually shows that it is powered by a (smaller sub*) battery (15:44)https://youtu.be/eYvjVXGBWXQ?t=944*my bad, the wording of the question is a little weirdit appears that a tiny battery powers the fuse circuit which would blow the bigger battery circuit

author: Someone
author_rank: Super Contributor
timestamp: November 27, 2023, 02:42:06 am
content: Fuse for battery, not battery for fuse.Where is the battery in the screenshot you posted? Looks like ceramic fuses to me.

author: moffy
author_rank: Super Contributor
timestamp: November 27, 2023, 02:46:19 am
content: It might sense the voltage drop across the fuse, hence it needs a supply i.e. battery, and provide a health indication, just a guess.

author: retiredfeline
author_rank: Frequent Contributor
timestamp: November 27, 2023, 02:46:55 am
content: Hopefully you'll never "power" the fuse. If you do it'll be time for a new one.

author: Phoenix
author_rank: Frequent Contributor
timestamp: November 27, 2023, 02:59:46 am
content: According to the tear down guy there are a couple of lithium batteries in the removable fuse part. They must power some sort of local sensing circuit that needs to be isolated from the main power and/or able to operate without power.

author: ejeffrey
author_rank: Super Contributor
timestamp: November 27, 2023, 03:28:39 am
content: Quote from: Someone on November 27, 2023, 02:42:06 amIt's the fuse for the battery and it has its own battery. At least some Teslas have a pyrotechnic fuse for the traction battery. It has a small lithium primary cell to activate it should the need arise.

author: uer166
author_rank: Super Contributor
timestamp: November 27, 2023, 03:53:32 am
content: Quote from: Someone on November 27, 2023, 02:42:06 amthis is confidently incorrect.. Older Tesla pack fuses have a small lithium cell to provide an independent power source for the pyrotechnics of the fuse. Newer ones have energy harvesting design that steals energy across the main sense shunt.The ceramic small fuses you see are very small "arc-taking" fuses after the main >500A or whatever pyro fuse blows (which cannot take the HV arc).

author: uer166
author_rank: Super Contributor
timestamp: November 27, 2023, 03:56:27 am
content: Quote from: moffy on November 27, 2023, 02:46:19 amThis forum would have a much higher quality if people didn't speculate about something they're clueless about..

author: floobydust
author_rank: Super Contributor
timestamp: November 27, 2023, 04:50:37 am
content: See: Pyrotechnic High Voltage Battery DisconnectUS Pat. 20130154352

author: Someone
author_rank: Super Contributor
timestamp: November 27, 2023, 07:12:09 am
content: Quote from: uer166 on November 27, 2023, 03:53:32 amThanks for the better photo, on the backward screen language sure is.

author: BradC
author_rank: Super Contributor
timestamp: November 27, 2023, 07:13:35 am
content: Quote from: uer166 on November 27, 2023, 03:56:27 amFTFY

author: coppercone2
author_rank: Super Contributor
timestamp: November 27, 2023, 09:51:53 am
content: what is the problem if someone hypothesizes about something. i think that's a good guessits like getting upset someone did not research patents for you