Do you need a larger HP engine to turn a 150 amp alternator?
Oct 11, 2007 by busboy | Posted in Engineering
I want to build a DC generator to charge a bank of batteries. The examples on the web show a standard GM alternator that puts out 60 amps or so. Wouldn't it be more effective to use 150 or a 200 amp alternator to charge the battery bank quickly? Does
Not really. If you just want to charge a battery bank then the 63 Amp GM Alternator would be the best, because you can get it for next to nothing at any scrap yard. The Amps are peak output, which would occur for only a short time, since the charging
-->X<-- | Oct 11, 2007
(2) Digital Designs 9518's with composite cones - Reaction #4
How much current does an Alternator source? Let’s find out…
How much electric current does a truck really use?
So, a while back my truck was getting slow to start. I checked the battery voltage with the truck running, and it was only 11 volts or something. I started the troubleshooting process by replacing the alternator with one from the local parts store, but it didn’t fix the problem. I changed both batteries. Still didn’t fix the problem. So I did some diagnostics with an ammeter and a voltmeter and figured out that my brand-new alternator was bad. I took it back to the parts store, where they gave me another one. I had them test it, and it failed on their bench tester. So did the next one. They finally gave me my money back and I bought one from Ford. It worked just fine.
While I was looking for alternators, I found some high output models. This sounds cool, but do you really need it? I pull a trailer pretty regularly, and I imagined that the trailer lights and brakes would be a pretty good additional load on the electrical system. I had also read that people buying these “high output” alternators had been disappointed with their actual output, so I thought it might be good to find out.
I wasn’t sure how dirty the output of the alternator would be, or how quickly the output might fluctuate which ruled out the use of an inductive current clamp. So I looked around and found a hall-effect current sensor from Allegro Microsystems. The manufacturer’s part number is ACS758KCB-150B-PFF-T . This sensor has a maximum current rating of 150 Amps, and outputs a linear 0-5V signal proportional to the current that passes through the device. It’s fast enough to record transients and will faithfully reproduce both AC and DC currents. The output of the sensor was fed to an Atmel ATMega8, which did ADC duties and sent the data out it’s UART to a MAX232 level converter. I just picked up the data stream with hyperterminal on my laptop. Excel let me manipulate the raw data and make some pretty graphs. I made the circuit with my CNC machine. Here’s what it looks like.
