Re: Replacement for Hitachi LR135-31 alternator?

Ray,

You got a couple of good answers so far, but I can not resist muddying the water just a little more. The rating published is often optomistic as referenced to sailboat applications as they seldom run at rated speed and are often charging at the top of the recharge curve so they won't be near the published capability.

There is an available 90amp unit that is a bolt-in kit. It will just take some looking as I do not have the part number available. I know of two of these installations that were done by owners. A Yanmar dealer probably would (expect to be quoted at least 250$us). Some sets I have installed were a 500$ alternator and separate regulator package and the owner has always been delighted.

Be aware that 90amp machine will eat near 2hp. That may be critical and if you currently often run at full rack (wide open), you may wish to include a field shut off to get those 2 horses back pulling. It will also destroy drive belts that were less than terrific. Always have at least one spare on hand.

I do several of these upgrades in a typical year. If you have any other questions, I'm here a lot.

Fair Wind and Smooth Sea
Matt Colie

ray lunder wrote:
Ahoy, I could only find one technical reference for this which claims
it's a 30 amp alternator. Could this be correct? That's immeasurable,
that's minuscule- that's nothing. I measured about 13.2v output at
idle and I had to rev the engine to over half throttle to get 14.4v
out of it. (my batteries were topped up at the time if that makes a
difference).
It's on a 12hp Yanmar one cylinder diesel and I'd like to charge my
house batteries (220AH) and a 12v starting battery. If I'm beginning
to understand these things I'm to look for an alternator which will
produce 30% of my amp hour capacity. Since I'll probably charge the
two systems separately I guess that's around 70 - 80 amps. My crank
pulley is about 4" diameter, O.D. to O.D.. I need a 3" foot model to
fit my engine. Any similar experiences, recommendations, empowering
observations? Ok, the spell chek is complete, I had eleven errors.
Thanks again.
.

Relevant Pages

  • Re: Advanced Battery Management
    ... with the site except as a satisfied user. ... Smartbank isn't an alternator controller though. ... the latest technology (ie able to withstand higher charge voltages) ... Coupled with batteries that can take that ...
    (uk.rec.waterways)
  • Re: External regulators (was NB Virgo)
    ... our boat uses a diode to split the charge between domestic batteries and a bow thruster battery. ... The diode causes a voltage drop between the alternator and batteries and the batteries never charged properly. ... Now whilst this *will* fully charge a deep cycle battery it will take a ridiculously long time. ...
    (uk.rec.waterways)
  • Re: Replacement for Hitachi LR135-31 alternator?
    ... Watts to HP....In 1492 Columbus divided the year in two and converted watts ... were a 500$ alternator and separate regulator package and the owner has ... house batteries and a 12v starting battery. ... produce 30% of my amp hour capacity. ...
    (rec.boats.building)
  • Re: Re: 24v / 48v Systems
    ... Seeing the dual output alternator posts has just made me wonder if anybody ... with 4 12v batteries in series (to give ... but I have just had a chap who ebayed a 24 volt fridge ... and he wanted to charge its batteries from a 12v alternator. ...
    (uk.rec.waterways)
  • Re: Replacement for Hitachi LR135-31 alternator?
    ... Volts produced from your alternator and amps are 2 distinct different ... As batteries are 12 volt if Your alternator puts out more then say ... If You don't have allot of draw down you don't need a high amp output ...
    (rec.boats.cruising)