Yammer Hitachi Alternators LR155-20 Replacement with LR180-03

[MJ84]

Hi All,

My LR155-20 55amp alternator has died. It was coupled to a Yanmar 2gm20FC, approx 2004.

Im looking at replacing with a larger 80A version fitted to 3 cylinder yammars, the LR180-03.

Can anyone see why this would cause problems electrically?

Physically, there is room

Thanks in advance

[captainjay]

If you are going to upgrade then upgrade. Balmar makes a 100 amp that fits your engine. You can and should also upgrade to their serpentine belt kit.

http://www.balmar.net/product/6-seri...-60-yp-100-sv/


http://www.balmar.net/?product=altmo...48-ysp-3gm-b-2

[MJ84]

Thanks for the thought, although cost is where I am, the Balamr alternator is 800, and another 600 for the external regulator kit.

This 80A alternator is under $400.

[MJ84]

Hi All,

Just to close this thread out, I fitted the LR180-03 alternator today to my 2GM20. Fits well, and works spot on.

[SV Bacchus]

And saved a $1,000 as well, good for you!

[Captsteve53]

In answer to your question NO nothing electrically to stop this working as others have indicated/ agreed, one point to check how ever and normally over looked, is just be sure the original cable size is heavy enough to handle the up graded amperage !, normally people do this with no issues and normally no repercussions, but in a situation say were the batteries are flat the alternator may be putting out a high current and the original cable cant handle it!!

Cheers Steve

[Stu Jackson]

Hitachi/Yanmar Alternators: (by Maine Sail)

Some alternators though, such as those made by Hitachi and found on Yanmar diesels, are dumber than a pound of beetle poop. Actually, to the alternator, they are pretty smart but to your batteries and the speed of charging they are flat out stupid. Why?

Hitachi alts with dumb regulators, and some others, limit voltage but also reduce voltage based on alternator temperature. This is a self protective feature installed in the internal dumb regulator to prevent the alternator from cooking itself. Remember voltage is the pressure that allows more current to flow. So, if we reduce the absorption voltage, then we also reduce the current the alternator is supplying.. The battery simply will not accept the same current at 13.4V that it did at 14.4V and as a result the alternator will run cooler. What do you suppose this does to your batteries over time.......?

The problem is that when cold you will get 14.3V to 14.4V out of the Hitachi but as the alternator heats up the dumb regulator begins to reduce the CV/voltage limit based on the alternators internal temperature. It is not uncommon to find a Hitachi alternator at 13.4V when hot. This is REALLY, REALLY DUMB....

If you have a dumb regulator, and notice the voltage dropping, it is likely a temp compensated dumb regulator. Get rid of it or plan to buy new batteries more often.

If you have a temp compensated alternator or a Hitachi alternator on a Yanmar you really are in dire need of external regulation if deep cycling a larger battery bank.

This is from:

http://forums.sbo.sailboatowners.com...d.php?t=125392

and these, too:

http://www.cruisersforum.com/forums/...on-125843.html


http://www.cruisersforum.com/forums/...or-142083.html

[delmarrey]

MJ84

I have a pair of slightly used 80amp alternators from a 4JH that I bought from a guy here on the CF that he upgraded to a pair of 120 amps.

If you like, I'll sell one of these (or two) to ya at a reasonable price, since I'm selling my vessel and these are just spares.

BTW a #4 wire is recommended for 80 amps alts up to 10'.