Rant on terminology...

upnorthandpersonal

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Ok, I need to get this off my chest. It's been bugging me for some time now, and a recent YT video made it worse.
Terminology matters. A lot. In engineering, words have specific meanings and these terms help us communicate ideas and concepts correctly. When people start assigning other meanings to these terms (especially in the same field) things become confusing, and the words lose their precision and surrender some of their function.

Why am I bringing this up? Two words: "Eddy currents".

Eddy currents have a very specific meaning in electrical engineering, that is, Eddy currents are "loops of electrical current induced within conductors by a changing magnetic field in the conductor according to Faraday's law of induction". The term "Eddy current" has nothing to do with the current that flows from one battery to another when you hook them up in parallel. As far as I know, it was Orion (from the Orion BMS) that started using this term incorrectly in this one document:


Sadly, other people are picking up this term and referring to this document with a "see, they're using it, they're Orion, it must be correct" (paraphrased). It's not correct. Orion is wrong (on more than one thing in that document, but I digress). Stop abusing terms with clear definitions that have nothing to do with the issue at hand or are even close to the meaning as set forth by the definition. Please use the proper terminology so we can all understand each other, and can continue to do so going forth. Use the correct terms, and don't try to assign existing terms and their meanings to something else. It's confusing, it causes communication problems, it serves no purpose.

/rant
 
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sunshine_eggo

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Unfortunately, the word "eddy" somewhat describes the behavior of the currents described by Orion.

There are eddies in the current flow between parallel batteries as Orion describes; however, describing them as "eddy currents" crosses the line into usurping a known phenomenon's label and assigning unrelated meaning to it.
 

upnorthandpersonal

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An Eddy is something that is also used in fluid dynamics, but has a specific meaning there too - the swirling of a fluid and the reverse current created when the fluid is in a turbulent flow regime. Different field, same term - no problem. The main problem is calling something an "Eddy current" in a field where "Eddy current" has a very specific meaning. If tomorrow I would write a white paper in the field of fluid dynamics and call water flowing from one tank to another an Eddy, people would rightly think I don't know what I'm talking about and discard anything else in the paper.
 
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upnorthandpersonal

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And don’t get me started about power vs energy misuse......

Makes me nangry (nerd angry) 😎

Related, this is my post a few days ago:

 

sunshine_eggo

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And don’t get me started about power vs energy misuse......

Makes me nangry (nerd angry) 😎

Hmmm...

Nerd angry = Nangry, check
Nerd mad = Nad, dang it... another example of why "eddy currents" in this context are bad, M'kay?

:D
 

Dzl

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I need a 200 amp battery man.

My inverter pulls 20 amp hours.
Its like a weekly ritual for me to clarify this difference in units with regard to the perpetually recurring questions (that apparently nobody even thinks to search for first before posting) about choosing a BMS for an xxx Ah battery, and clarify that the capacity of the battery bank and the current rating of the BMS are not connected to one another.

To be fair, I do see how it would be easy for newbies to confuse this in their mind, and it took me a damn long time (and a lot of pestering/learning from people better educated than myself) to gain a somewhat intuitive understanding of some of the units and concepts (still I struggle with some concepts--the math of solar cells, bypass diodes, and shades still goes over my head).
 

HRTKD

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I have a cousin Eddy. Dude is frickin' crazy, but in a good way.

At least we aren't arguing over if current flows on the surface of wire.
sasmokin.gif
 

FLD

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I'm an idiot about most things. I'm reasonably smart about one or two subjects and electricity is NOT on that list. I'm not shy about saying "I don't know" when I don't know. I'm ok with that.
My personal peeve is with the camper owners (and camper dealers) who use "converter" and "inverter" interchangeably, while expecting everyone to understand what they're talking about.
 

HRTKD

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I'm an idiot about most things. I'm reasonably smart about one or two subjects and electricity is NOT on that list. I'm not shy about saying "I don't know" when I don't know. I'm ok with that.
My personal peeve is with the camper owners (and camper dealers) who use "converter" and "inverter" interchangeably, while expecting everyone to understand what they're talking about.

And "charger".
 
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