Alternator question

I have a quick alternator question. When I buy my RMW for my first car, me and my friend are doing modifications that require an alternator larger than the 140a stock one. Does anyone know of alternator, at least 200a, that will fit on a 1994-1996 RMW? Thanks!

http://www.ebay.com/itm/NEW-ALTERNATOR-HIGH-OUTPUT-200-Amp-4-3L-5-7L-CHEVY-CAPRICE-IMPALA-94-95-96-/130682234541

Apparently Andy knows.

Zena inc made in USA 3 year warranty configuration can be done for WELDING. High output at low rpms. Absolutely bulletproof A fellla showed up at my house to do some welding and I asked him where his Miller was. He said "MILLER Smiller mines under the hood" moved it from his Ford 250 to his new Duramax, has had it 4 years w/o a problem. Have a set up for audio fanatics, but you still need to increase your battery bank These guys are pros. http://www.zena.net/htdocs/alternators/alt_inf.shtml

Zena diode/rectifier is external keeping heat to a minimum

I have another problem that relates to alternator. Note again that I do not own a RMW yet but I will soon. I'm too lazy to type this all over again so here's a hotlink to my reddit post:
https://www.reddit.com/r/AskElectronics/comments/3qzwgy/power_inverter_for_mini_fridge_and_microwave_in_a/

If this can work, I plan to use this inverter:
http://www.amazon.com/Cobra-CPI2590-2500W-Professional-Inverter/dp/B00S9S8NA4/ref=sr_1_1?ie=UTF8&qid=1446321660&sr=8-1&keywords=2500w+inverter

with these cables:
http://www.amazon.com/2-AWG12-12-Foot-Professional-Inverter-2000-2500/dp/B000J1AQS6/ref=sr_1_13?ie=UTF8&qid=1446321784&sr=8-13&keywords=inverter+battery+cables

this is what you need,..

I just installed a 200amp Powermaster alrernator. Not cheap...but well made.

http://www.jegs.com/webapp/wcs/stores/servlet/KeywordSearchCmd?searchTerm=713-58112&storeId=10001&catalogId=10002&resultCatEntryType=2&Ntk=all&Jnar=0&Ne=1%2B2%2B3%2B13%2B1147708

The fridge/microwave unit shows a current draw of 11 amps -- no indication if that is peak with both running or what the fridge itself draws when the microwave is not in use.

11 amps x 120v = 1320 volt-amps. The wattage will probably be less, but as we don't know the power factor, and as that inverter produces a modified sine wave, let's take the worst case and assume a PF of 1, so watts = 1320 as well.

From the on-line manual for that inverter, efficiency = 83% and no-load current = .6 amps. Assuming an average battery voltage of 12v, then current draw to provide that power = (1320/.83)/12 + .6 = 133 amps.

Let us assume a battery with a reserve capacity of 120 minutes. Reserve capacity is a measure of how many minutes a battery can supply a current of 25 amps continuously (ie: 50 amp-hours). 133/25=5.32, so 120/5.32 = 22.56 minutes of use before the battery is drained. (of course, the reserve capacity diminishes as the battery ages, so that only applies when the battery is new).

That said, the unit shows an Energy Star rating of 223KWH/year. Which works out to 26 Watts per hour. So, 2.16A/.83 + .6 = 3.21 amps/hour. Under ideal conditions (eg: car interior ambient temperature = room temperature, fridge door kept closed, microwave not used, etc.) that same 120 minute reserve capacity could last up to 15.6 hours. And with the door closed, your insulin will keep a little longer than that before the fridge interior heats up to the point of degrading the medication. I don't know about insulin, but an epi-pen can withstand short periods of up to 90°F.

There's quite a few assumptions going on in the above calculations, so I wouldn't bet my life on complete accuracy. I wouldn't even bet your life on it. But they do confirm what the others have suggested: get a big alternator. If you are going to try and run this fridge/microwave and a fancy stereo, 200 amps may not even be enough. Either shell out for a 250 or 300 amp unit or, as phantom309 suggested, convert the car to multiple alternators (4 might be overkill, but 2 would certainly be reasonable).

As for cables, certainly bigger (diameter) is better, and shorter is better. Copper is better than aluminium or steel, so run both a positive and a ground between the alternator and the battery, and between the battery and the inverter. Perhaps more important than cable size, connections must be kept clean and tight.

Oh, one other thing: you won't get the maximum rated current out of any alternator at idle. The maximum rating is for an alternator shaft speed (NOT engine rpm) of 6,000 rpm. The idle output (1500rpm shaft speed) is often half that. So if you are thinking of running the microwave off generator output when stopped, you will definitely need a much bigger or dual alternator(s). Or a brick on the gas pedal.

brokecello wrote:

I just installed a 200amp Powermaster alrernator.  Not cheap...but well made.

http://www.jegs.com/webapp/wcs/stores/servlet/KeywordSearchCmd?searchTerm=713-58112&storeId=10001&catalogId=10002&resultCatEntryType=2&Ntk=all&Jnar=0&Ne=1%2B2%2B3%2B13%2B1147708

I might do that, but will this fit?
http://www.jegs.com/i/Powermaster/713/482038SPL/10002/-1

Talk to this guy:

https://alternatorparts.com/cs144-series-high-output-alternator.html

I have no affiliation, but I did buy an alternator off him and found him quite knowledgeable regarding what fits what.

Try these outstanding, buddy has one on a GMC van for welding ! Big output at much lower RPM than any Delco or clone. great 3 year warranty even when welding, and you will have to drastically upgrade cables. http://www.zena.net/htdocs/alternators/alt_inf.shtml All American build and componets compact also due to external rectifier/regulator .

Well, it is a CS144 alternator...but I think we need the one with threads in the back for a bracket (however, I bet if you call Powermaster they can tell you or make one to your specifications. I've owned these before and they are great with customer service and warranty work)

But, I guess you need to figure out what amps you need at idle. I didn't quite get the scope of your project at first! Should be interesting!

TheRoadmasterKing wrote:

brokecello wrote:

I just installed a 200amp Powermaster alrernator.  Not cheap...but well made.

http://www.jegs.com/webapp/wcs/stores/servlet/KeywordSearchCmd?searchTerm=713-58112&storeId=10001&catalogId=10002&resultCatEntryType=2&Ntk=all&Jnar=0&Ne=1%2B2%2B3%2B13%2B1147708

I might do that, but will this fit?
http://www.jegs.com/i/Powermaster/713/482038SPL/10002/-1

That welding one looks like it might be too long to fit the LT1. The back of the alternator has to clear the rocker cover.

buickwagon wrote:

That welding one looks like it might be too long to fit the LT1. The back of the alternator has to clear the rocker cover.

I mean, I like the idea of being able to weld with my future station wagon, but is it really necessary? I just want something no bigger than 300 amps so I can power my inverter and audio systems...

Necessary? Changes owner to owner.