Second Alternator On/0ff switch?

[Speedy]

First will it hurt the alternator to run it long periods without being on. It is a CS 130 200amp.

I suppose you would use a relay wired back to a switch inside the cab. Hook the relay up to the I or L terminal to turn it on?

What kind of relay would be best or does it even matter, it is just a switching wire?

Would it be okay to just wire S terminal back to the of the alternator output?

I am going to run 2/0 from the alt to 2 950 cca batts back in the bed. I might bump it up and run 2 2/0 cables just to make sure everything will work well. I can't find any lugs that have a 1/4 hole for any cable size bigger than 2/0...


Will two batteries be enough or will it cook them?

How critical do you have to be about matching lengths when running two cables parallel?

It wouldnt hurt it to fuse the charging wire 2/0 by the alternator before it heads to the back?

Thanks

[Cain64]

Im some what knoledge able of this, from what i know but am probly wrong so dont hold me to it.
But, you should be able to run another alt. and have it on all the time but with a regulator in it so
when the batterys become charged the alt. willput out less power and not re charge the batterys as much,
i am not sure if you can put a swithc on the the alt. though.

Also running different runs might be a plus, a rule of thumb is if you can go bigger then
by all means do it, having 2 runs will put less "stress" on a single run.

And now about fusing, i would say that you should fusing is always just an extra precautionary,
just in case, thats why they are there"just in case" now most of thetime when doing an install from a
battery you always want the fuse closest to the battery, so it can stop any damage that could happen.
With this much power i would have both fused at the initial power and before the battery.

[Sheriff Bart]

I'm not sure what alternator you have but most can be turned off and on by energizing and de-energizing the field. A 20 amp rated toggle switch is sufficient for turning the field on and off. If the alternator is a one wire type (just the large cable that goes to the battery) then a relay is appropriate for switching the alternator on and off.

[Speedy]

No it is not the one wire type. So looks like il just run it off a switch..

Thanks for the help.

[jessejamesdallas]

It will not hurt the battery's to have the alternator charging all the time. (or rather turned On all the time) Where most people mess-up, is by thinking a "Alternator" charges the battery's...

It does NOT charge the battery's!

A "Alternator" Maintains the battery's charge...If you have a low battery, then the alternator will try and maintain the low battery, which usually leads to the alternator burning-up after a while...

This is why if you leave your lights on, and run a battery dead, it's a good idea to hook up a battery charger to the battery first, and re-charge the thing before using it...Driving on a battery that has been run dead, and letting the alternator try and charge it back up, can cause the alternator to over-heat and burn up, or the battery will not re-charge back to it's original charge, and eventually get to where it's not holding a charge.

Another way to look at it, is the alternator is going to try and keep the battery charged to 12v's and however many amps the battery is rated at. The regulator on the alternator is set so it will only charge to 13-14v's. And if the battery is fully charged (amps & Volts), then the alternator will only be maintaining that charge...It won't be trying to put more in the battery, if the battery is "Full"...

What "Kills" a 12v battery, is a alternator that is charging at over 15v's...15v's into a 12v battery will literally boil it's self to death...

Don't believe me? Just ask any one that rebuilds alternators if a alternator charges a battery, or just maintains the battery's amps and volts...

Generators "Charge" batterys....Alternators "Maintains" Batterys...

[Speedy]

Well i just wanted to be able to turn it off when not using the amp, there shouldnt be any draw on the batts if the amp isnt on. I figure if a turn it on atleast one day a week or so unless iam running the amp then it will be on the whole time... I guess it will just depend on how much adding a second alternator will bog the motor while driving and the impact on fuel mileage whether ill just leave it on all the time. Its just a 305. Runs well thou. I guess you could say i just wanted the option.


I wish my factory alt was on the pass side like yours be much easier to add the second one. Did your burb come with both pass and driver side battery brackets or did you steal one from a deisel. I looked at Tmc but they don't have them...


Thanks again.

[jessejamesdallas]

Well i just wanted to be able to turn it off when not using the amp, there shouldnt be any draw on the batts if the amp isnt on. I figure if a turn it on atleast one day a week or so unless iam running the amp then it will be on the whole time... I guess it will just depend on how much adding a second alternator will bog the motor while driving and the impact on fuel mileage whether ill just leave it on all the time. Its just a 305. Runs well thou. I guess you could say i just wanted the option.


I wish my factory alt was on the pass side like yours be much easier to add the second one. Did your burb come with both pass and driver side battery brackets or did you steal one from a deisel. I looked at Tmc but they don't have them...


Thanks again.

No...On mine where the battery is at on the drivers side, there use to be a plastic storage box. (I guess for something like jumper cables to go in) What I did, was just bought a battery tray from (I think) Walmart, and mounted my second battery where the plastic box was at.

Now on my Suburban thou...those two battery's are hooked together and are just being charged by the original alternator (sort-of...I up-graded the alternator to a 200 amp, original one was a 105 amp)...The second alternator (also a 200 amp) charges 3 battery's that are in a box in the back of the Suburban, which is just hooked-up to my 8-pill...and is "ON" all the time the motor is running.

There is something to be said about "Fuel Mileage" thou...With the alternator running all the time, it will pull down the motor some, although I haven't noticed all that much of a impact on mileage with mine. I have a 350 and it is still getting close to what It did when I first bought the thing in 97...250,000+ miles on it, and I'm still getting over 15 MPG...(New it was only rated @ 18 mpg)

[Speedy]

Sweet well maybe i just wire it to the ignition. Hell probly just tap off the switch wire for the factory one.. Yea mines a 87 with 219,000 on it i just had the trans rebuilt last year, original motor far as i can tell and i get around 15 or more depending on how i drive it. Doesn't smoke at all except for a little bit sometimes on start up if i haven't drove it in a while.

Iam pretty much doing the same thing separate charging system for a 8 pill....Cant wait for it to warm up.

[PYRO-736]

The good thing about having a secondary alternator is that you have the ability to shut it off therefore letting it freewheel without drawing on the motor if its not needed. That way your gas mileage wont suffer 24/7 especially on roadtrips.

[MECHMAN]

Just let the alternator run normally all the time. If there is not an electrical load present, the alternator does not offer any more resistance against the motor. (that's what the regulator does) I run three alternators, and have had no perceptable change in gas mileage unless I am loading them down with big current draws.

Oh, and I doubt very much that your CS130 actually does 200 amps. If it does make 200 amps peak, the stator would have to be so aggressive that you would have zero output till above 1000 rpm engine speed. Even if it did make 200 amps, it would overheat in a matter of minutes, they just don't have enough rectifier and cooling to run at 200 amps. I cringe every time I see someone on the internet trying to sell a 200 amp alternator based on a small case GM housing, they are lousy units.

Matt

['Doc]

I agree with just leaving the thing running all the time. As was stated, if there's no load, then there's no draw, the alternator may be turning, but it isn't doing anything but turning. If it affects your gas millage at all, then there's something else going on. Sort of like having one tire with one pound less air pressure than the other three, big deal.
- 'Doc