bertram31.com

Need to upgrade/replace the Alternators.

3208T CATS, with original 100amp alternators, external regulated.

What should I replace them with?

Do you have a need to upgrade to a bigger alternator. If not just match what you have. Not sure what your needs are.

Long before solar and battery stuff for homes, I did a number of Catamarans who didn't want to use a generator with battery banks and Balmar alternators.
They were they only game in town then but I'm sure there are others now.
The biggest issue is high output alternators get hot and need a good heavy case to be a heat sink. They have external regulators that are pretty easy to set depending on the type of batteries.
You may well know all batteries do not charge at the same rate and voltage.

Standard alternators only put out max charge at around 5500 rpm so to get max charge you have to make sure pully ratio allows them to spin that fast vs crank speed. Most manufacturers don't.
Externally set regulators can help with this that are adjustable.

Get yourself a genny

I upgraded my Cummins OEM alternators to a couple of Balmar XT 250 DF4-SP with a couple of the Wakespeed 500 external regulators.

Which are charging 1080 amphours of batteries. If you're interested in going this route you're welcome to check out my installation.

I don't have a generator, but I have a builtin Fridge/Freezer and AC.

Rick,

What kind of fridge/freezer?
Did you construct it yourself or was it purchased ready?
How thick of an insulation?

My fiberglass guy made mine. top loading, 70 liters fridge, 30 liters freezer, 10 cm insulation around fridge, 15 cm around freezer.
Drawing from 3X100 amp batteries filling with sun juice.

I went the easy way and purchased a Vitrifigo DRW180A. Its a two drawer fridge/freezer. Either drawer can be either a fridge/freezer. It runs on both/either 12V DC or 120 AC.

For anyone looking at Lithium batteries, the new guys one the block are Epoch. They are selling a 470 amphour battery for around $2K usd and are compliant with AYBC recommendations.

Presently have the stock Delco Alternators that came with the package that Bertram put on the boat when it was built in 1983.
Have external regulators.

They just do not work well at this point, and would like to bring this setup into the Present Century.

Yes there is a Genset on board, and yes it will charge the 2 8D batteries, thru the charger.
(Well…it will, when I get it out of the garage, and into the boat)

These present alternators are just old Tech, and chew thru belts.

I feel it’s just time to use the new tech that’s available for Electrical generation.

Time to put new life, into her old bones, and I’m about to start tearing everything apart.

Was looking at the Prestolite Leece-Neville alternators.

Make life easy for yourself.

Decide what type of New external alternator regulator that you want first. The wakespeed 500's are well known and supported. You can get them through Dragonfly. Ask them which would be your best alternator. Which ever way you go, you are likely going to want to upgrade the pulleys to use a serpentine belt.

Ironworker,

Would love to see your setup.

Agree.
Running high output alternators on V belts is a pain. Two belts minimum. Back when flat belts weren't an option I did custom 3 belt drives.

Kevind767 wrote: ↑Feb 1st, '24, 01:33 Ironworker,

Would love to see your setup.

Kevin,

You're a fair ways from N. Palm Beach but you are welcome to come see it in person. I hope to be taking the boat to the Bahamas for 3 or 4 months in March. Another option, I'll be happy to upload some photos to dropbox if you would prefer that.

Dropbox would be great.
I used to have the boat at a friends house just north of Prosperity and Northlake, but won’t be down that way in the foreseeable future.

Kevind767 wrote: ↑Feb 8th, '24, 11:33 Dropbox would be great.
I used to have the boat at a friends house just north of Prosperity and Northlake, but won’t be down that way in the foreseeable future.

Wilco, I'll get some photos together and get them uploaded