put the alternator to good work?

[gabi]

this is somehow related to the thread battery booster,

http://ecomodder.com/forum/showthrea...ter-16142.html

is just a little bit reversed

basicaly i'm thinking of recharging the battery booster while breaking or driving down hill, only, making the alternator work harder,

any car alternator has technicaly double the power that the car needs,on a regular basis
my car needs around 60 amps on regular driving but the alternator is rated 135 amps.

so in theory i can safely add around 50 amps of extra load to the alternator,but lets just say i only do 20.Still good enough.

i guess the question is if the alternator will come on the second i put the extra load on? and will it go off or reduce power the instant i take the load off.
if it realy works that way would be a good way to save on the brakes too
also would be interesting to see how much the car will slow down

what do you guys think?
thanks

[Frank Lee]

If it's breaking you will want that booster.

[usergone]

Well, if you look at it from a physics standpoint...

20 amps * 14 volts = 280 watts
280 watts / 746 = .375 hp

Assuming that your alternator is 100 percent efficient (no, it is not) the 20 amp load would only provide a measly 3/8 hp more braking.

But... if you are in DFCO mode, all the power comes from your momentum, and any load other than brakes slowing you down saves wear on the brakes. This just won't do a whole lot. Something that would be more noticeable would be to turn on ALL loads when in DFCO, because you could probably feel that.

[mort]

If the alternator is 50% efficient then you get twice as much braking for the same elctrical load. But to compare, for a 3500 lb car a quick stop, but no ABS, might be going from 60 mph to 0 in about 10 seconds (about 0.275 g). That can be done with a constant load of 77 hp - 4000 amps at 14 volts.

-mort

[gabi]

ok,
i still want to do this , but i still couldnt find if the alternator comes on instantly when extra power is draw,or the power will come from the battery and the alternator will kick in later to top off the loss

i have a battery gauge in my car ,and it shows less voltage instantly when i add extra load, and comes back up instantly when the load is reduced,

the only question is if this is battery itself,or the alternator, or a combination of both?

[mort]

Hi Gabi,
I think this is a great idea to test out. I don't know what car you're going to modify, but most cars with alternators have a voltage regulator somewhere to regulate the alternator. The alternator will supply an almost constant voltage (about 14 volts) to the electrical system if it is rotating fast enough. That means if there is a load the alternator increases its current output to match the load. It is as instantaneous as can be.

If you are thinking of the 10.5 volt Li booster thingy, then as soon as you plug it in the alternator will be trying to bring it up to 14 volts. It should look like a hefty load, until something melts.

-mort

Originally Posted by gabi

ok,
i still want to do this , but i still couldnt find if the alternator comes on instantly when extra power is draw,or the power will come from the battery and the alternator will kick in later to top off the loss

i have a battery gauge in my car ,and it shows less voltage instantly when i add extra load, and comes back up instantly when the load is reduced,

the only question is if this is battery itself,or the alternator, or a combination of both?

[Vtecsauce]

why dont we enable the alternator to be on when the foot brake is on ... i think that should be fine..

maybe a switch to over-ride if need it be on permantly ....

i use a ev200 contactor to enable/disable the alternator charging..

it brought me from 37mpg - 42 mpg!

[gabi]

Originally Posted by mort

Hi Gabi,
I think this is a great idea to test out. I don't know what car you're going to modify, but most cars with alternators have a voltage regulator somewhere to regulate the alternator. The alternator will supply an almost constant voltage (about 14 volts) to the electrical system if it is rotating fast enough. That means if there is a load the alternator increases its current output to match the load. It is as instantaneous as can be.

If you are thinking of the 10.5 volt Li booster thingy, then as soon as you plug it in the alternator will be trying to bring it up to 14 volts. It should look like a hefty load, until something melts.

-mort

i drive a crown vic police interceptor 2003, the alternator is rated 135 amps, and a typical load from the ford manual is about 60 amps,
i'm pretty sure i'm using about half than that, since i changed to all LED lights, i don't use the radio, try to keep the heat and cool at minimum, also i have two 5 watt panels on the back window that help( dont really see 10 wats unless i take them out)

it will be nice if i can use all that extra power that the alternator is capable , for regenerative purpose

now that i know that it works how i want it i'll try to look for parts and how to do it

any ideas about how to do it ,or what parts to buy, are MOOORE then welcome,
I definitely don't want to melt anything thats for sure

i also like the alternator kill switch idea, don't know if will work just as good though, for one thing it can put to much strain on the battery, and second it might not "work" the alternator as hard as the other mod

[Ryland]

Even tho your alternator might be able to put out 135 amps, the rest of your wiring might not be able to handle that many amps and you would need to beef up your ground straps as well as clean all of the connections, otherwise you are going to fry something, or set your car on fire.
also check the fuses, your alternator might be fused at 60 or 80 amps.

[MarkM66]

Originally Posted by Vtecsauce

why dont we enable the alternator to be on when the foot brake is on ... i think that should be fine..

maybe a switch to over-ride if need it be on permantly ....

i use a ev200 contactor to enable/disable the alternator charging..

it brought me from 37mpg - 42 mpg!

Would you explain a little more about how you did this?

Where did you buy the ev200 and how much was it?

Does your battery ever go dead?

Thanks