Good grief, it never ends. Alternator upgrade needed.

[sailandbail]

The alternator on my Perkins 4108 stopped producing a charge a couple days ago, about 2 weeks after I installed a new battery bank. It's the original alternator on the engine of my 1979 Cooper Sea Bird and had done an adequate job until now. I knew that the day would come that I'd need to take this plunge because power demands are higher than they were 40 years ago, so I'm ok with it (though it's not super exciting spending a bunch of $).

I just got off the phone with the folks at TAdiesel.com, specifically the Balmar specialist, who was incredibly helpful and friendly. They are the only ones I've spoken to so far because I've just started to do my research. They sell a kit that includes a 70 amp alternator, a regulator, temperature sensors, and a harness for $950. He mentioned that I could get an alternator with higher output if I planned on adding to my system down the line, but I'd need a serpentine pulley kit for a larger alternator which is another $675.

I'm a novice with this stuff and couldn't be more grateful that I've stumbled upon this site because it's already been an amazing, friendly resource in the couple weeks I've been here.


I currently have four 115ah 6 volt "golf cart" batteries.

My questions are:

-Would you go with Balmar?

-Is 70 amps sufficient if I added a couple more batteries in the future, or would I be completely limiting myself?

-Is an alternator something that is smart to buy new?


Thank you in advance for your input, I appreciate it so much. Luckily the joy of cruising still outweighs all of the work, time, and investment involved in keeping this vessel afloat.

Evan

[admiralslater]

I would go a bit bigger so that you have the extra capacity for the future. Balmar should be able to give guidance. I am going to fit serpentine belts . Less dust ,wearon bearings and the ability to drive larger alternators. Balmar has a good reputation

[john61ct]

Originally Posted by sailandbail

I currently have four 115ah 6 volt "golf cart" batteries.

Good choice, assuming they are FLA.

Note a 70A rated alt should be fine until you get past double that bank capacity. Going higher will not charge any faster.

Have you got solar to handle "the long tail"? How many hours a day do you motor?




> Is an alternator something that is smart to buy new?

Yes, or newly rebuilt.



Balmar is fine.

Check out whatever Maine Sail's selling, if it will fit.

Mark Grasser also good stuff.

Whatever you get, make sure the voltage put out is close to the top end of the range spec'd by your batt mfg.

[Cheechako]

For the money I would want to be getting a 100 amp alternator. Make sure the regulator you get is adjustable. (If your belt squeals a lot at 100 amps you want to be able to back off a bit)
There have been a ton of alternators used on that engine, so there must be a lot of choices out there.
It all depends on how much of a do it yourselfer you though.

[roberttigar]

Any alternator shop can "juice up " a Delco Remy alternator to 80-90 amps. Are they as good as Bamar...no, buy mine for my 4-108 orignally cost about 125 originally and it seems every 3-4 I have take it in to replace the bearings or diodes...Rebuild cost 50-60. Been doing this for 20 years. Hours of eng-approx 250 /yr.
I keep a spare and have a separate regulator with was approx $250

[rbk]

Just did this upgrade as well as others on my 4108. I went with the 120 amp w/ MC regulator and dou charge (x4 6v GC2 house bank and separate starter but 430ah capacity, yours seems small for similar setup) Serpentine pulley upgrade etc. Money well spent to make the most out of your batteries. The nice thing with this setup is if i decide to upgrade my battery bank the charging systems can accommodate.

[rbk]

oh check out craigslist southeast alaksa, guy has x2 120 or 150 balmars and regulator(s) for sale $400 for each setup, not that old.

[Singularity]

I think you can do this yourself (unless you're in some kind of rush) for maybe 1/2 of the numbers giving in the original post. This would be using a reman alternator with all the other hardware the same as the initial quote, and would be using an alternator with more production capacity.

Apparently S&W Diesel (Wilmington, CA) has the pulley kit for a couple-few hundred less than TAD (for exactly the same pulleys...just a markup thing). Worth price-checking around.

Consider checking out this thread:
http://www.cruisersforum.com/forums/...-202839-7.html

[a64pilot]

Nothing wrong with Balmar, however your paying a lot for the name.
My alternator is a Mark Grasser alternator and I’m very happy with it.
I am running a Balmar controller though, cause at the time Mark didn’t have his new controllers out, he does now.
I’m not familiar with them though.
http://markgrasser.com

[roverhi]

It's my understanding you can get by with single belt pulley alternator to about 80 amps. Don't know if you'd gain much by going larger. The built in charge controllers on alternators cut back the charge voltage/amp output quite quickly as the battery is charged. So the additional amp output of a larger might only do you any good for minutes. An after market charge controller from Balmar or others might be a better investment and wouldn't require a serpentine belt kit.

Rebuilding the current alternator with an after market controller would be an affordable way to go.

[hlev00]

I replaced the stock Hitachi on our Yanmar with a Balmar kit including serpentine belt. I had some fit problems but they were specific to my Yanmar model. Mostly pretty straightforward. I bought the 100A but use the regulator to derate a bit as concerned about temps. I have a similar bank size as you. I added solar which does most of our day to day charging. Alternator very helpful when sailing at night with chart plotter, radar, and autopilot in use. Remember to check / upgrade the pos and neg cables. They are likely undersized. The regulator wiring was pretty easy though a good wiring diagram of your existing engine / alternator will be very helpful.

[Lepke]

I use GM CS-144 alternators on my engines. 140 amps stock. Detroits, 4108 and Onan. At 140 amps they need double belts or serpentine. Kits are online for bearings, etc. Easy to rebuild yourself. About $100 new on ebay and $30 in a wrecking yard. Also 250+ amp versions for about $250.

[hlev00]

Also you should investigate how much additional side load your Perkins crankshaft key or waterpump can handle. Google around for things like "perkins side load alternator upgrade". For example. That might influence how big you go.

[john61ct]

Again you will buy absolutely **nothing** by increasing amps output with that FLA bank, they just do not **accept** more than .12-.16C, and even that for only a very short time, quickly scale down for the next 5-6 hours at least.

Don't throw money away on a fantasy

[Jim Cate]

Originally Posted by john61ct

Again you will buy absolutely **nothing** by increasing amps output with that FLA bank, they just do not **accept** more than .12-.16C, and even that for only a very short time, quickly scale down for the next 5-6 hours at least.

Don't throw money away on a fantasy

On the other hand, if he bought say the 140 amp GM alternators that Lepke mentions upthread, he would be running them well below ratings, and that has some real advantages in longevity. Since his current battery bank will limit the max current to ~ 80 amps there is no immediate need for upgraded belts, but the option is there for future battery bank expansion.

Considering the significant cost advantage, looks like a pretty good option to me.

Jim