Electrical upgrade

[David M Jackson]

I have a 1978 Hunter 27 with the normal 1 cylinder Yanmar engine. It has a alternator with an output of 35 amps. I'm looking for suggestions on upgrading to a larger amp alternator and other modern upgrades which you may have found useful.
I have already upgraded to LED lights, a windlass, nice Fusion stereo, and a Garmin GPS.
Suggestion on the alternator would be truly appreciated.
Dave Jackson

 

[charris]

I'm using an ElectroMaax (https://www.electromaax.com/) and so far very happy with it. They have a multitude of models, and importantly they have serpentine belt kits where you can replace your single sheave pulley with a multi groove serpentine which just does not slip under load. Be careul you don't overdo it though, that smaller engine can only handle so much load which can be considerable with a HO alt. I have also seen that Balmar is offering these similar kits and they are a quality alternator also

 

[Stu Jackson]

It all depends on how you want to use your boat. If you marina hop, you need change nothing. If you want to begin to deal with self sufficiency, then begin to understand electrical systems and charging, including a hefty house bank to support your loads, and solar.

This discusses what is most likely your alternator's background:

Hitachi Alternators 101 http://forums.catalina.sailboatowners.com/showthread.php?t=166123 This comes up so often on other boating forums...

 

[GorillaToast]

I asked this same question several months ago. Here's the thread...
Balmar Alternator for Yanmar 1GM10?
Discussion in 'Musings With Maine Sail' started by GorillaToast, Mar 27, 2015.

 

[seadaddler]

I am thinking that your 1hp yanmar needs all the help it can get
and a bigger alternator with take away HP for sure and maybe make your boat under
powered for sure.
Nick

 

[David M Jackson]

Good point well taken!

 

[David in Sandusky]

We have cruised our '77 h27 away from shore power for weeks at a time on the stock alternators on the original diesel and then our newer 1GM10 with one battery. Our only loads when the engine is off are the lights, the radio, and an occasional charge for the iPhone.

If you run the engine while using your windlass, I don't see why you need a larger alternator. Ours would easily keep a second battery charged, but we haven't needed that yet.

 

[Bill Roosa]

As other posters have indicated your boat usage will drive your electrical production choices. The first step is to determine your daily (or weekend or weekly.....time between charges) Amp-hour (Ah) load. You also need to decide on how you want to recharge the batteries. Running the engine once a day for an hour is only one way of doing it, solar, wind, genset are others. They all have advantages and disadvantages so consider them all and combinations. After you decide on loads you have to have and how you want to live on the boat battery recharge wise it is time to determine the storage capacity you need to support your recharge method and boat lifestyle. This calculation will change the way you look at your electrical production so be prepaired for an iterative process to "hone in on the solution"
I have a spreadsheet that takes lots of the math out of the process and lets you "what if" the various loads, storage, and production.

 

[Stu Jackson]

Bill's spreadsheet is good, here's another:

The All-Important Energy Budget:

http://c34.org/bbs/index.php/topic,3976.0.html

Record of Daily Energy Use of 100 ah per day:

http://c34.org/bbs/index.php/topic,6353.msg41471.html#msg41471

Largest House Bank 101 (by Nigel Calder)

http://c34.org/bbs/index.php/topic,5807.msg45046.html#msg45046

 

[Bill Roosa]

And yes there is a steep learning curve for this stuff. By Calder's book for the tour-de-force discussion on anything electricla (and lots of other stuff). Almost as valueable as "Sailmakers Apprentice" by Emiliano Marino
My take on the spending of monies on boats is invest in yourself and books first and equipement second as the first informs the second and you spend less overall. FWIW

 

[GorillaToast]

And yes there is a steep learning curve for this stuff. By Calder's book for the tour-de-force discussion on anything electricla (and lots of other stuff). Almost as valueable as "Sailmakers Apprentice" by Emiliano Marino
My take on the spending of monies on boats is invest in yourself and books first and equipement second as the first informs the second and you spend less overall. FWIW

Really good advice from Bill. I have both books and have learned a great deal from them.

 

[David M Jackson]

I appreciate your insight on this. Thanks

 

[David M Jackson]

I appreciate the wealth of knowledge that all of you have and sharing it with me has helped me make a decision. I'm going to keep my 35 amp alternator use more solar power and do more homework. Thanks again for your help.