Increasing Alternator output

[domains]

Re: Increasing Alternator output

Prop pitch yes thats it if everything checks ok .nice info. buy a very low pitch your only trolling.

 

[Texasmark]

Re: Increasing Alternator output

I don't know what the component density is under the flywheel. You may have no more room for a larger alternator if one were out there. My brochure was '95. I know in the larger engines 75-125 they offer several alternators.....obviously there is room for the largest. Maybe you can get another for yours.

Something just hit me. Some mfgrs have alternators for manual and larger ones for elect start. I know elect start on a 9.9 is sorta out of the question but it wouldn't hurt to ask. Even if you didn't get the starter, you could get the alternator. I know Chrysler used to have an elect start 15 and maybe a 9.9 also. Don't reember......not avocating you change engines, just that they do make starters for small engines.

Like in the equation, you need the rpm's to get the "dt" down to pump more cycles per second into the battery to get your charge up.

I like the idea of reducing consumption, or forcing your engine to run faster, like was mentioned, in reducing the thrust of the prop.

Good luck,

--------------

Just did some homework for you.

9.9 and 15 have same block (16 cu in) but also the same alternator which is used up through the 25 hp which is a 24 cu in block. No luck there.

The larger block 30 hp still 2 cyl, but 39 cu in., uses 2 alternators: a 140 watt for manual start engines and a 226 for elect start. Maybe there is some lift there.

Mark

 

[bubblehead]

Re: Increasing Alternator output

The motor is an electric start 9.9 I've been researching the interchangeability of a newer alternator, but have not gotten an positive results as of yet. Will advise if feasible.

Thanks for the input.

 

[domains]

Re: Increasing Alternator output

Like you said only charges at higher RPM's ,smaller prop will help.

 

[j_martin]

Re: Increasing Alternator output

The advice I see here about just changing the stator under the flywheel is probably wrong.

The engines that offer different alternator capacities use different stator and flywheel combinations. Sometimes if you change a 16 amp to a 40 amp by changing both, the cover won't fit over it. (1988 XR4 v6, personal experience)

Coupla things come to mind.

If you deeply discharge your battery and don't recharge it with a quality charger immediately, you will greatly reduce both it's capacity and it's life. Mechanical bumps and vibration in a discharged state increase the damage.

There are two ends to this equation, more power, or less draw. I've blown all the regulators out of a 18' 150 horse bass boat with the engine battery supplying 2 depth finders, 2 live wells, bilge pump, and starting power. Fished all day, didn't kill the battery with reasonable management, like cycling the live wells. It was deeply discharged by the end of the day, however.

Possibly a slightly higher trolling speed will help. If it does you could get it by changing prop pitch or venting it.
Prop pitch also effects high speed operation. You could overrev your motor. On the other hand, if you're lugging it now, it could help there also.
Venting will allow the prop to slip at slow speed. If the boat can't get moving at a pretty reasonable speed, the prop may never bite. We vent the props on the big boats all the time. At about 30 mph, the water over the hub pretty well shuts off the vents. When you floor a 150 and it spools up 70 percent or so before the prop bites, you get a neck snapping hole shot.

I feel your pain, or drive, or whatever it is. I like things to work the best they can, to the point of rewinding or rewiring things, or redesigning electronic controls, or whatever it takes to get what I want. You have to do your homework, though. If you have a simple rectifier system, you could probably get away with rewinding the power coils on the stator with one gauge lighter wire and a few more turns, or just more turns if there's space for it. If you get more voltage at low speed, you will also get more at high speed, and you will also get less current at high speed. The over voltage could take out the rectifier if it does not have a high enough back voltage rating. The point is, it's a system, not just independent functions.

hope it helps
John

 

[Motor Boater Bill]

Re: Increasing Alternator output

Take a lesson from the current state of life on earth--instead of trying to create more energy, use less energy! The LED's are a great idea--the future of all lighting. Just my two cents.

 

[domains]

Re: Increasing Alternator output

I un winded burnt stators before to get fresh wire then weld to connection, after I was told less of a nice spark but only 2 turns out would not see a difference. And there was a good post stated that might not be enough room to whind more that 2-3 turns more . yellow stator wires are thicker than red wrapped. So can't whind much i guess. I know most ATV's charge at 14.2 at hidle .