Logo
FULL SITE MENU

Alternator amperage

G

glenmoor51

New member
"I am looking at purchasing a

"I am looking at purchasing a delco one wire. I want to hook up radar, gps, radio, electric downriggers, and possibly a few other electronics. I was also considering a second battery.

My question is, what would be the correct amperage size alternator? My choices are 60, 105, or 140 which I can purchase on ebay for under $100. I believe that the alternator I currently have on my AQ130 is 60 amps, but I have no electronics and only one battery."
 
"Yes, you are talking about th

"Yes, you are talking about the Delco 10 SI Marine alternator. I too use them and have had OK luck with them.

David, Engine alternators cut back charge rate rather quickly after initial charge....... so there is sort of a misnomer about buying a 100/120 amp alternator and thinking that a charge rate of even close to 100 amps will be maintained. It will NOT! (and your wiring system probably wouldn't handle it anyway)
The alternator will certainly charge your battery banks....., just not at the rate, nor in the time frame, that most of us think that they will.

We must think in terms of Amp Hours used.... and Amp Hours charged back to the battery.
This takes time if using an engine alternator, no matter how you slice it!

Best to keep a good cranking battery on your # 1 position of your MBSS (main battery selector switch), and install a House Bank of Deep Cycle batteries large enough to handle your other loads on your # 2 position of your MBSS!
Then rely on a good three stage smart charger for when you return from an outing and connect to shore power (if so equipped).
A smart charger is the way to go...... Batteries left in much of any state of discharge will certainly have their life shortened.

."
 
"Thanks for the feed back Rica

"Thanks for the feed back Ricardo!

What do you mean by OK luck? Is the 100 amp better tham the 60 amp? The last thing I want is too be stranded with dead batteries. Is there a manual or website that will walk me through a dual battery setup as well as hooking up my electronics to this setup? I have never ran dual batteries, as the last boat I had was a single battery with multiple electronics. I never had charging issues with that boat, but I think I would feel more secure with multiple batteries.

Thanks in advance for your feedback!"
 
"I run them.... have two on my

"I run them.... have two on my own boat! They work well.
As for what amperage; It's right there..... second paragraph.... "Misnomer about buying a 100/120 amp alternator and yada yada and so on...................."
I'd run a 65 or 70 amp and call it good!

Here is a simple schematic showing a very conventtional battery configuration.
http://sports.webshots.com/photo/2362442900035924090XidrOD]
url]
[/URL]"
 
"It might be more to it than j

"It might be more to it than just hooking up a new alternator.
I take it you have the original set-up, which is a 35Amp alternator and a 9,5mm belt driven by a sheet metal pulley. That may give you en effective output of about 17Amps at 13,8Volts.
The max you may load the std belt and pulley with is about 50 Amp nominal, which leaves you with the 60Amp alternator that will give you just below 30Amps of effective output with conventional regulator.
As for battery set up there are similar rules.
If running 2 ore more batteries and a conventional 'manual' split using a main switch (1 - 2 - All), the banks should be at even size (capacity) and same type. Do not mix lead/acid with dry-cells etc. As you will probably be running the engine at the same time as the consumers, I would suggest to go for 2 deep cycle batteries of 90/110 Amp hours each. One for 'start', one for 'accessories'."
 
"David, your question was rega

"David, your question was regarding your choice between the Delco 10-SI 60, 105 and 140 amp alternators, and your comment was that you have a 60 amp now.

After thinking about your engine harness, etc. I agree with Morten..... I'd install no more than the 10-SI 60 amp.
You do not want to over-burden your engine harness and the rest of your system."
 
"Hey Guys,

So I purchased t

"Hey Guys,

So I purchased the Delco 10 SI alternator about a month ago, thanks to some help here, and went to bolt it up today. The problem I ran into is that my alternator bracket on my AQ130 does not line up with the Delco 10 SI. Any sugesstions on a bracket I could buy, or should I take the boat to a shop and have one custom built?

Thanks for the outstanding support!"
 
"I have used the same alternat

"I have used the same alternator on an AQ130, AQ140, and an AQ311 (and if I remember correctly, on an AQ240 as well). To a point, they are pretty much universal. What are the physical differences between your old and new ones? Could you upload some pictures?"
 
"Thanks for the timely respons

"Thanks for the timely response El! As you can see from the front view the bracket is too short, so when I rotate the bracket to line up with the hole on the alternator it will be even shorter. On the side view, there is a gap which I figured I could use washers to solve that issue. Thanks for your assistance!

294565.jpg
Front View"">
294566.jpg
Side View
 
"I assume you are talking abou

"I assume you are talking about the "tensioner", and not of the "bracket". Correcting the tensioner length is not a problem. If too long, cut it and weld a piece of flat bar of the same width and adequate length. I had to do that myself a couple of times, but it is not a big deal. Also, to correct the gap, you can either add a spacer or (even better) bend the tensioner in two different points.

Also, have you tried a shorter belt?"
 
"My mistake, I am reffering to

"My mistake, I am reffering to the tension bar as the bracket is a smooth fit. Thanks for your input as I will take it to my buddy and see what he can do for me, as I don't have the tools to do so.

Thanks again!"
 
Back
Top