It's been a few years, but I have returned. And here again.

[Getting Serious]

I was wanting everybody's inside on possible off-grid stand-alone type charging and also a standalone workbench alternative testing.
I have two of these batteries
http://www.neobits.com/alpha_technol...UtmykBz_oH8M3-
I want to hook up one of these 1/4 hp motors with V belt pulley to a 10 SI alternator when I rebuild them
https://www.amazon.com/gp/aw/d/B006P...KIKX0DER&psc=1
My entire thought is the alternator provides power to the GM alternators and at the same time the alternators will be recharging the batteries and telling me if the alternators are fully functional again. The batteries will power the alternators to start up and run and in turn the alternators will recharge the batteries. The electric motor turns at 1750 RPM and only 1200 approximately RPM is needed to get the alternators to start charging. the motor will run off of batteries that are in turn recharging the batteries through the alternators. My thoughts, or continuous stand alone testing and charging. Independent of any outside power ever. As well as being able to charge or run anything else I might need the batteries for. As I said before it's been a couple years since I've posted in here. I very much missed this group and I hope everybody is doing well. I'm also looking at converting these alternators to permanent magnet for generator uses anywhere else this is just a stand-alone tester that I'm trying to build.

[KINGCHIP]

Welcome back. Interesting angle.

[Winni]

We're not talking about a perpetual motion machine, are we ?

[macaw]

As Winni would imply this would not be sustainable. It would take more energy from the batteries than would be created by such a setup. For this idea to work the alternator would have to be greater than 100% efficient. The laws of entropy dictate that, in addition to electricity, heat would also be created by both the motor and alternator, also, the battery would itself generate some amount of heat as it is discharged. This creation of heat (wasted energy) makes this endless loop impossible.

[91CavGT]

Yep, as Macaw stated, it won’t work. The laws of physics deem nothing can work at 100% efficiency. What you are wanting to do would require, at bare minimum, 101% efficiency in order to keep the batteries charged.

[Getting Serious]

It won't be something running permanently. More than likely I will have a backup alternator mounted to it as well with a hundred amp diode protecting the primary alternator on the system. A lot of alternators are standard 60 to 70 amp. But also, a lot of them are a hundred amp as well. Something that when I rebuild the alternators each one. I can mount it to the machine and flip a switch turning it on long enough to test the alternators. Having two batteries it in series to keep the voltage the same but at least I have enough power to get it going while getting a lot of the charge returned for the whole time it's running. Eventually with the permanent mounted alternator. It would be converted to permanent magnet so it doesn't have any resistance and consistently charges when/if everything runs low on Power. I guess fooling around with it and trial-and-error might teach me a couple things on the system and what it needs.

[Junkman]

Go for it serious. Just remember it takes a lot of horsepower to make a 70 amp alternator put out at maximum. Try hooking a car alternator up to a stationary bicycle.

[Getting Serious]

At some point, I may eventually try to hook up a small horizontal shaft engine to it. But I live in a 20 floor apartment complex that is disabled and elderly housing. They have pretty much nitpicked everything I have claiming what I save or prep with is somehow junk because none of them are intelligent enough to know how to save anything. People are so wasteful anymore and are quick to call me the hoarder. I'm around morons everywhere

[91CavGT]

Go for it serious. Just remember it takes a lot of horsepower to make a 70 amp alternator put out at maximum. Try hooking a car alternator up to a stationary bicycle.

This. I have a small 50 amp alternator hooked up to a gas 3hp engine and use it to recharge my 450 amp/hr battery bank in emergencies. At full throttle it only puts out about 30 amps.

[bruss01]

We're not talking about a perpetual motion machine, are we ?

That was my thought when I read it.

Obviously there would be losses from mechanical friction, battery inefficiency, and wiring resistance that will gradually drain the energy from the system.

Not sure I fully understand the purpose.