alternator size

[Bob Gil]

I am wondering if I can use the one that I have (160amp).

I took the old burn't up one to the shop today, they told me it was a 100 amp.

I know the lady real good I have been doing business with them for several years.  She is the one I bought the Lacee Neville from a while back.  She suggested that i use it if I could.  Will it be too much?

It has two post on the back of it one pos and one neg.  Do I hook those straight to the batteries?  I don't think that is the best thing to do there should be some thing else there to keep the batteries from getting run down when not charging.

I am starting from scratch as it all burn't away.  I am in a Big Learning Curve here hope I make it.

Dallas it made it today thanks.

[compedgemarine]

there should be an on/off switch between the batteries and the the starter and coach feeds, this lets you turn it off and kill all power from the batteries to everything. on my Eagle the alternator goes to this switch so that it would only send a charge when the switch is on. the same post is what the starter wire is hooked to and the coach power is hooked to. I dont know why it would not work if you have a good way to mount it. it will only supply what is needed so if the original was 100 amp and was ample then this one will never work hard. you may want to consult the alternator people as to what pully to use so it runs at the correct speed.
steve

[JohnEd]

How big your alt NEEDS to be is a function of "how many deep cycle bats you have" and how many amp hours they are.  If your alt can charge what you have at the  MAX RATE then you can run your engine the SHORTEST period to get the bats back up.  You never discharge these deep cycles more than 50% so the capacity needs to be viewed as half the mfr spec.  Add more bats for more power....not discharge deeper as looks logical but is not correct.

100 amps is whimpy even to charge the starter bats.  After you pass 175 amps money starts to happen real fast.  The S&S from Monaco come with 190 amp units at 12 volts.  I can get those local for @$180....just to give you an idea. 

I sure hope the heavys chime in here as they have it all down pat....formulas and all.

good luck,

John

[DrivingMissLazy]

I question the need to place a switch between the battery and the alternator. I have never seen a switch on anything but a bus. Never on an automobile or truck. Maybe someone has a good explanation why?

Richard

[Busted Knuckle]

I question the need to place a switch between the battery and the alternator. I have never seen a switch on anything but a bus. Never on an automobile or truck. Maybe someone has a good explanation why?

Richard

Richard, I have always been off the same opinion that they don't put them on cars & P/U's, and even most big trucks. But at the same time I had several big trucks that had them and if they was gonna be parked more than a day, you'd better have used them or you'd have dead batteries when you tried to start it. Now on every MCI, and most Eagles & Prevost I have been around have battery discounnects. And again most of them have some sort of phantom load that will drain it to a no start state, if left on while parked. Now on the other hand I don't know why tehy don't do like Setra and use a massive relay that shuts off the power when the key is turned off. Never been a problem that I am aware of.   BK 

[DrivingMissLazy]

I agree with you. The phantom load is a real problem. I finally got mine all disconnected so that I did not have a dead battery after sitting for a couple of weeks. The last item I discovered was an older electric clock that actually ticked as the second hand moved. After that I never turned the battery disconnect off.

Richard

[Lin]

My alternator looks to be the same size as one that would go on a V8 car.  I do not know the output but guess at around 100 amp at 24 volts.  Is there an easy way to determine the output?  I felt that, since I do not intend to run A/C through it, it is probably quite adequate to keep the bats charges.  Another thought was that it would be easier to switch out in a pinch if I kept it small.  I probably should keep a spare on hand though since I doubt that 24 volts alternators are a common roadside item.  At some point though, I should attach a separate 12 volt alternator for the house bats, but I am not there yet.

[buswarrior]

If we parked our cars for weeks at a time, we'd be hearing about dead batteries and phantom loads in a big hurry, you can be sure!

And dumb end-users own cars, easily taken advantage of by knowing manufacturers.
Trucks and buses are owned by business people seeking a profit.

Completely different design and execution philosophy:

One is intended to break sooner, the other, somewhat later.

happy coaching!
buswarrior

[belfert]

I agree with BW here.  Modern cars have all kinds of phantom loads that kill batteries. 

I worked at a winter storage place about 15 years ago.  The cars all went out the same day.  We found that most of the classic cars started just fine, but all the fairly new sports cars had dead batteries from computers and radios draining them down.