Alternatives to the alternator

[cfg83]

Unheard -

Originally Posted by Unheard

just found this Permanent Magnet Alternators and Water Pumps

This looks really cool. If it is compatible with my Saturn + If my alternator or fuel pump fails + If I can afford it, then it may be my replacement option down the line.

CarloSW2

[metromizer]

How about this hairbraned idea?

Add a large auxillary battery, a selector circuit, and an alternator disable feature. It could work like this: Charge the aux battery at work and home. Run the car off the aux battery in 'total loss' mode (that is, no charging by the alternator). If you are on a long trip, or if you fogot to plug in your car, or half-dozen other problem come up, the 'smart circuit' senses the low voltage across he aux battery's terminals, and switches over to the OEM alternator/battery. The so-called smart circuit wpuld need to monitor the OEM batteries condition as well, and isolate the two like my old camper did.

A couple downsides include weight and space (aux battery, charger and relay switches), one more thing to break (although I could imagine a simple knife switch bypass).

Add a forklift battery and charger, then coming up with an appropriate relay and 'smart circuit' ? Leave the OEM battery and alternator in place. Charge off the grid, or better, off photovoltaics. Use a large enough aux battery to run the CPU, lights, wipers, radio, etc.

I'm not battery guru or electrics expert, why is this a dumb idea?

[Vince-HX]

i would like some more info on permanent magnet alternators. Are they a good amount more efficient?

[cfg83]

metromizer -

... Add a forklift battery and charger, then coming up with an appropriate relay and 'smart circuit' ? Leave the OEM battery and alternator in place. Charge off the grid, or better, off photovoltaics. Use a large enough aux battery to run the CPU, lights, wipers, radio, etc. ...

It sounds like a good idea to me, as long as the second battery is used according to it's design specification, i.e. don't run it below whatever charge will reduce it's lifespan. I think the forklift batteries are the "marine-style" deep cycle batteries, right?!?!?! If yes, then I think those can be run pretty low. I always like the option of "switch back to stock" running mode. The best of all worlds (at the cost of additional weight).

I think we need a battery guru to make a "battery comparison thread" that describes the types of batteries and their applications/specifications.

Google google google ... Here's a FAQ on deep cycle batteries :

Deep Cycle Battery FAQ

CarloSW2

[modmonster]

if you EOC doesn't it switch off the alternator as well? i can "hear" my battery voltage through putting the fans on full-blast and listen to them speed up and slow down with EOC.

[dcb]

Sure Mod, Your unmodified alternator is driven off the engine. If you turn off the engine then the Alternator and the water pump and all the engine accessories stop turning also.

[wagonman76]

I think a switched alternator and extra battery is a great idea. Just think last time your alternator died, you were probably able to go quite a ways with it not working. Itd be the same thing here. Top off the battery at home or work, and for the short trip that the average person does, youd do just fine, even better with an aux battery.

I really do think some kind of monitoring is best, so you dont get it so low that you wont get the car started if you shut it off, or end up really shortening the life of the battery by draining it way down a lot.

I wonder about even some sort of pulse width circuit one could make for the field coils, like charge for 10 seconds and stay off for 50 seconds, adjustable based on current draw from the battery. (Pulse and glide for your alternator!) Might be able to be done with a 555 timer but Im not real good with electronics. Maybe even too with a relay controller like Siemens Logo or AB Pico, or with a pulse timer controller for dust collectors. Just thinking of things Im familiar with at work.

I wouldnt run the alternator off the trans output shaft. Then if you get stuck in traffic, you might as well call for a tow truck now. Unless you leave your original and put in an extra one that runs off the output shaft, and switch field coils as needed.

[Noel]

I've been watching the amp gauge I installed to get an idea of how much power I would need for my rear battery....

With EOC, My alternator was putting out 50 amps last night during pulses to make up for when I was coasting with it off.... That's quite a draw...

[CobraBall]

Permanent Magnet Alternators sounds like a non-contradicting-oxymoron .

If it is an ALTERNATOR it produces ALTERNATING CURRENT, hence the word ALTERNATE.

If the gizmo has Permanent Magnets imbedded in the thang, a generator and it generates DIRECT CURRENT (DC). A generator can also be used as a motor.

Magnetos are great if you are operating a race car, but not very reliable in a street vehicle. Besides to stop the darn engine you must have a grounded kill switch to stop the thang from running. You turn off the key and it will still run. Really, really, safe......not!

Be careful if you have an ammeter. The two posts on the back of the gauge carry the FULL amp load. If is is showing 50 amps and you accidently ground the two post, you get 50 amps of 12-15 volts DC. IF that happens you may need to change your shorts. And there is a fuse in the ammeter lines ???

I wonder how long a car battery is going to last if a guy or gal keeps farting around with the alternator trying to save a few cents. Get rid of the multiple stereo amps & multiple speakers. You save fuel and your hearing.

[dcb]

Originally Posted by CobraBall

You turn off the key and it will still run. Really, really, safe......not!

but, dude, it is trivial, I mean trivial, to set up a magneto to turn off with the ignition key! Don't play the safety card on that!