The first part I knew from the previous threads, donīt think I was in the main one where they were discussed with the ad nauseum degree, but I did browse it. I just already had one to use. It mounts to the back of the back-seat better.
Alas I have too many ad nauseums.
Many are beneficial, others are distractions from an OP POV. I think it was with doncarbone there was a lengthy distraction about battery isolators - for BOATS! (I have yet to see a reply with any hypothetical reason for using a "boat type" isolator in car...).
Then there are distractions that are nothing but misinformation. Many get sorted out, but I suspect others still think LEDs need resistors and PWMs need capacitor filtering.
It is rewarding to learn, or enlighten - especially when others have the patience, curiosity, and trust to persevere and finally get it - else correct the nee-enlightener. But it is easy to drift - personally...
Eventually most of it comes together. There is always more though....
Wot? Oh yeah...., alternator sizing. Then (a second?) battery. Hopefully a cheap "ultimate intelligence" isolator (aka SPST relay or FET).
And a voltmeter.
What do you mean by ultimate intelligence isolator (what is SPST and what is FET lol)?
Originally Posted by OldSpark
You'll have to excuse my limited understanding when it comes to electronics. I guess I didn't pay attention too much in physics class a few years ago when we briefly touched on simple circuitry and formulas lol
Thanks for the help as always, OldSpark. You definitely know your stuff!
Ah - the UIBI... it should have been Patented...
To heck with school & physics - it's places like this you get the real stuff & innovation!
But that you didn't understand the UIBI in that Newbie's thread Having two batteries, one solely for start-up, the other deep cycle -- relay switch?... Oh, that's right, it got hijacked with irrelevance....
But as a perceptive person wrote on that thread:
And as yet nobody has been able to explain WHY any voltage sensing battery isolator is superior to the method OldFart describes. (Which underpins the main philosophy...)
Originally Posted by a CleverLeaner
Note for the inexperienced - a collapsed battery does NOT incur a lower charging voltage - hence why batteries boil and AGMs suffer thermal runaway.
IE - a (6-cell) 12V battery with one collapsed cell will still charge at (say) 14.4V, hence 2.88V/cell instead of the max 2.4V charging and 2.3V float voltage. Although that is very damaging, the battery is stuffed anyhow - the main issue is safety.
& BTW - "charge lights" are normally "not charging" indicators. When not charging, the alternator and sensor circuit outputs are GND or off etc. I mention that because someone said they had a "not charging indicator" - that's what a typical alternator L or D+ circuit is.
I figure if marketeers can call voltage switched isolators "smart" isolators, then I can call the L/D+ isolator "intelligent". After all, it has been designed with greater intelligence and been through far greater risk assessment & case study than the voltage isolators - or rather, the UIBIs suffer less problems than voltage sensors (ie, no delays required, no hysteresis or set-point issues) as well as being more reliable (circuit-wise, but also in general situations).
I might Register the UIBI name if the design originator decides to Patent it.....
And I think the originator ended up using a FET - hence a UIBI on ANY alternator or "charging sensor" with ~5V or higher output (when charging) costs about $3 for about 100A switching capacity.
SPST is "Single Pole, Single Throw" - aka basic on-off contacts (whether switch or relay etc).
A FET is Field Effect Transistor, a semiconductor like a transistor and akin to a relay - ie, less electricity turns on or controls more electricity.
eg - a relay has its small coil/solenoid current input which closes very heavy contacts for larger currents.
Transistors & FETs are similar - a small base/gate current or voltage enable a larger current flow through its/their other terminals (Collector/Emitter or Source/Drain).
FETs are good for switching because they just need stuff all power to control very high currents - eg, a Gate with 5V @ 1uA can turn on the Drain-Source with its 100A. (But such high power FETs are usually called MOSFETS (Metal Oxide Silicon FETs if I recall).)
I often recommend Wiki for answers to such questions. Look for the simple verbals and good pictures - avoid the maths and jargon....
And keep looking back from time to time - more begins to make sense...
But keep asking here or me if still unsure....