Hunter P42 1997; has anyone upgraded alternator to a Balmar system with the alt mount blue pulleys?

Ralph Johnstone · Oct 22, 2016

BBC16385 said:
We have the Hitachi 80 amp alternator (worthless)

Before diving into the cost and trouble of the new alternator and mounting brackets, I'd suggest taking a look at the alternator regulator and your sailing habits.

If your regulator is not a smart one and not putting out a healthy voltage (as high as 14.7V) which it's not, take a look at installing a smart regulator. Loads of info in the archives here.

Terry Cox · Oct 22, 2016

BBC16385 said:
We have the Hitachi 80 amp alternator (worthless)

Would you please be more specific about its worthlessness? The original one our 1991 boat seems to produce its designed output depending upon battery state. Maybe someday it will stop producing, thus at that point will move to the worthless category. Just wondering.

Karl13265 · Oct 22, 2016

BBC, I have a 1995 - 40.5 with a 4JHE installed. When I bought the boat it came with the same 80 amp. Hitachi alternator that you have. The PO had installed a Balmar System including the Smart Regulator and a Digital Duo charge unit to charge the two 8D AGM home batts. and an AGM start batt. Last spring I found out thru bench testing that the alternator was producing no power and had given up the ghost. I looked into a Balmar high output charger but due the exchange on the Can/US dollar decided to investigate other options. I finally settled on and bought a high output unit from a company called Electromax, I bought the 160 amp kit that can be dialed back to a 130 amp output if you want to. I bought the kit which included the alternator with serpentine pulley installed, the pulleys for the freshwater pump and the crank pulley, a serpentine belt and a very neat and easily adjustable alternator bracket. The whole system was a breeze to install. The alternator has an internal regulator which can be disabled in order to tie into the external Belmar Smart Reg/Digital Duo charge components. On installation I could not get the system to work and after several phone calls to Belmar found out that the Digital Duo charge would not work due to output fusing issues. The Belmar Tech I spoke to told me to install a Blue Seas ARC that was large enough to take the 160 Amp output of the new alternator. On purchase of the ARC, I decided to completely do away with the Belmar components and following the Blue Seas techs advise, wired the system via the alternators internal regular, the Blue Seas ARC using 2/0 cabling and three high amp fuses in the circuit. On first start the new alternator starting putting out 14.5 amps according to the Hunter Amp gauge and has done so all season. The 2 8D's and the start battery are always well charged and I have had no issues. Electromax has both a Canadian and an American distribution center and I would highly recommend their system to anyone.

Charles Erwin · Oct 22, 2016

Terry Cox said:
Would you please be more specific about its worthlessness? The original one our 1991 boat seems to produce its designed output depending upon battery state. Maybe someday it will stop producing, thus at that point will move to the worthless category. Just wondering.

Terry

Your Hitachi is an automotive design. Here is an article that explains why an automotive alternator 'designed' output will not work well in our cruising boats.

https://marinehowto.com/automotive-alternators-vs-deep-cycle-batteries/

Now if all you do is start the motor and go sailing then no problem. In that case all the alternator does is recharge the one starter battery which has delivered a very small amount of its capacity and thus is never very depleted - just like your car .

However, a cruising boat also needs to charge a large capacity house bank and that bank replenishment needs considerably more charging voltage and for a longer period of time. This is especially so when the bank is deeply discharged. In charging that battery bank your automotive style alternator cannot deliver enough voltage for a long enough time to get the house bank replenished.

The short of it for cruisers is that unless your alternator is running 10 hours a day the automotive alternator will be a disappointment when it comes to keeping up with house battery replenishment.

But - if you just use a battery to start the motor - or if you charge by a generator (and do so regularly) then your relatively anemic HItachi may be just fine

Charles

Terry Cox · Oct 22, 2016

Charles Erwin said:
But - if you just use a battery to start the motor - or if you charge by a generator (and do so regularly) then your relatively anemic HItachi may be just fine

Thanks Charles. This is our situation, which is why ours does the job it was designed to do. May not work for others as they acclaim.

Maine Sail · Oct 23, 2016

BBC16385 said:
We have the Hitachi 80 amp alternator (worthless) and are considering upgrading to Balmar 120 amp with regulator and alt mount blue pulleys with 1 inch grooved belt. See http://www.balmar.net/?product=altmount-pulley-kit-48-ysp-4jh-e

Has anyone done this on the Yamnar 4JH2 engine? I would like to know about your experience with the pullies, the wiring and the results.

Thanks in advance.

I have done plenty of these kits and they can make a big difference. If you are really going to be placing a high demand on the alt for long duration's, 30 minutes plus, always up-size the alternator and then de-rate it with the regulators Belt manager feature. In other words if you expect a 85A -120A alternator output go with a 120A or 150A model. You will also want alternator and battery temp sensors.

The installation is critical to actual performance and voltage sensing is the most often incorrectly wired aspect of a high performance alternator. Alternators & Voltage Sensing - Why it Matters (LINK)

Without knowing your bank size, battery type and daily expected Ah consumption we really can't make any solid sizing suggestions. All we can say is that any unit you buy will perform significantly better than the stock Hitachi, which is essentially an automotive alternator.

The reason they perform so poorly is written about here: Automotive Alternators vs. Deep Cycle Batteries

Maine Sail · Oct 23, 2016

That wiring is totally insufficient for a new alternator. Heck it is insufficient for the stock alternator. When doing the new install the wiring harness gets opened up and the red and black 10GA wires completely removed and replaced by 2 GA to 2/0 GA depending upon amperage and length of run to the house batteries..

The isolator needs to go. These murder charging performance especially with stock alts. It can be replaced with an ACR to feed the start battery once the new alt is installed and wired properly to the house bank.

- Remove isolator and toss it in the round-file where it belongs.
- Wire the new alt directly to the house bank.
- House bank (two 8D's) should be contiguously wired as "one battery"
- Alt B+ wire needs a fuse at 150% of alt rating within 7" of battery positive
- Alt B+ should have a "service disconnect switch" in the engine room, clearly labeled for service techs.
- Alt B- needs to be same size as Alt B+

Look at this diagram for how the alt B+ & B-, & all charge sources, get wired into the bank. The ACR charges the start battery from the house bank when any charge source is providing voltage above 13.0V..

charris · Nov 15, 2016

This system has been working well for me. Set up pretty much as per the above drawing. We have a 160 Amp alt, Balmar MC612 Regulator and the Blue Seas ACR. We use the Balmar Regulator programming to derate the alt down to about 100 amps or so. We used a serpentine pulley kit, as anything over the 80 amp Hitachi is going to lead to belt slip with a single belt. The serpentine belt gives so much contact area that there is just no slippage at all. No black dust going into the alt. The alt does get hot when working hard, we have an alt temp sensor so we throttle it back when it gets too hot. Would love to have a forced cooling hose directed onto the alt but have not got around to that yet.

Maine Sail · Aug 30, 2017

BBC16385 said:
The rest of the story:
In April, my brother and I installed a Series 6 Balmar 100 amp alternator . The problem was this was the largest alternator that would fit in our space. Now we actually get real charging off the engine. Glad we made the switch.

Glad to hear it worked out & thanks for the follow up..

FWIW the Balmar 6 Series is available in 4 amperage's that are dimensionally all the same. The 6-Series is avaible in a 70A, 100A, 120A and 150A outputs. If the 100A fits then the 120A or 150A also fits....