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yachtplanb 03-17-2007 12:18 AM

100 amp Alternator recommendation needed
I am currently looking for an alternator recommendation. I have a Ford Lehman 90 diesel and plan to use wet cells as my starting bank and will use 6 volt trogan golf cart batteries for my house banks as well. This is on a heavy displacement cruiser.

I also need to select an inverter/charger and battery monitor as well.

I have looked at the Balmar alternators and would like to get opinions if the premium price is worth the difference, or are other viable alternatives.

Any recommendations or experience positive or negative would be helpful. :eek:


sailingdog 03-17-2007 01:03 AM

Just curious... how many T105's are you using for the house bank. The size of the bank will determine what size charger that you will need and what size inverter you can support. Might also affect which battery monitor is going to be best for your setup.

ianhlnd 03-17-2007 04:05 AM

I don't think it's a good idea to mix batteries, you might want to check that one out with your battery supplier. In addition, if you're using wet cell, do you have access to them to check their level on a regular basis. Also, if wet, are they properly tied down, etc.

sailingdog 03-17-2007 08:34 AM


Trojan T105 golf cart batteries are generally wet cells, not AGM or Gel, unless you're willing to spend a good deal more money. I don't see a problem with mixing the batteries, as both are wet cells and are in separate banks.

I do agree that you need to have relatively good access, to be able to check the water levels and that they need to be tied down securely and in a proper battery box.

Freesail99 03-17-2007 08:48 AM

I had a 50 amp alternator on my Volvo Penta engine. I had a local auto electric shop rewind the alternator. It is now 90 amps. It cost me under $100.00 to do that.

camaraderie 03-17-2007 09:02 AM

I've upgraded to Balmar alternators on my last 2 boats and found them rugged and reliable with absolutely no problems in extended cruising use. I also use their smart regulator which lets you quickly diagnose any charging issues and set the proper charging regimen for various types of batteries. For a monitor we use the Link system which interfaces nicely with the Xantrex charger/inverters. The Link is used every day to monitor what is going on with our banks and charging and is one of the most valuable pieces of equipment we have on board.
The choice of charger/inverter will depend on the size of your banks and the equipment you will be using. There are both modified sine wave inverters and pure sine wave inverters with the latter being more expensive and needed if you use equipment that is sensitive. The drawback to the sinewave units is that they use a lot of amps in the standby mode. We have used high quality modified sine wave (Heart2500) without problems on board and experienced no problems with microwave,flat TV, PC and assorted other devices but apparently some are more sensitive than others.

Valiente 03-17-2007 12:18 PM


Originally Posted by camaraderie
The drawback to the sinewave units is that they use a lot of amps in the standby mode.

I have the Xantrex RS 2000 inverter/charger, and my idea is to simply TURN IT OFF when underway rather than draw standby amps. I don't really find the "12:00...12:00...12:00" of the microwave a huge issue. I believe I can use this device to monitor DC loads, feeds and draws as I charge via MPPT-limited solar panels, the alternator (if motorsailing) or via the generator, for which the Xantrex charger would have to be "on", I suppose.

My remaining question is do I need a second Link type interface to read loads, or will the System Control Panel work with the inverter disconnected?

kavakava 03-17-2007 12:54 PM

We added a Powerline 120 amp alternator with a smart regulator to our 56 hp Yanmar last Fall. Purchased at a package price from e-marine. Seems to work very well, but haven't had it too long. We too are planning to change from 2 4D's to 4 6v for the house bank. Have easy access and plan to use water miser caps to minimize water usage.

yachtplanb 03-17-2007 10:10 PM

Thanks for all the replies. I plan to use all wet cells and they will be located under the seatte in the pilot house to ensure I have them way above flood level to provide me with the most run time in case the bilge starts to take on water and it will be easy to service them there.

I have not determined what my final house load and subsequently house bank will be, but plan to install a diesel gen set once everything else is done and will size appropriately. I suspect in the 600-750 AH range. Probably a 6 KW generator unit to help run the a/c. We are here in the tropics and it does get hot if we have to shut up the vents to keep the mosquitos out. I will use the genset to drive the invertor/charger or will use a PTO for a high output DC charger on it. In any case the 100 amp alternator in question will be used to primarly charge the starting bank and the house bank only while underway. At anchor I will use the gen set and keep the wear off the main engine. I have a huge bilge area so lots of room for a gen set and I can still walk around it. One reason I bought the boat I did. This will also give me several options for charging the batteries at anchor as well.

Thanks for all the info, if anyone else has any additional information they are willing to share regarding brands of alternators they are happy with please let me know.

Again I really appreciate the info.


Loewe 03-18-2007 10:31 AM

Remember that alternator ratings are at specific RPM's. Also I am seeing a lot of good advice on securing the batteries but don't forget to properly enclose and vent your bank. Remember the Hindenburg! ;)

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