Need a new alternator

[jordanbigel]

Originally Posted by HarrisonM

NYSail:

Any chance you could share "Rod (mainsail)" contact info?

Harrison
harrison.midkiff@gmail.com
Tarpons Springs, Florida

https://marinehowto.com

[bcboomer]

I put in an industrial alternator 4 years ago. It is a small frame brushless unit rated for 200 amps that pumps out 185 amps without over heating. $320 Canadian.
It needed a little bit of modification to the mounts on the W46 and I had a machine shop make serp belt pulleys for another $300.

[witzgall]

Chris from Balmar here. If you are damaging the diodes in one of our alternators every 100 hours, then there is something about the installation that is causing problems. I would make this statement about any high quality alternator, not just ours.

Likely you have a bad ground or ground issue, a corroded or intermittent connection, or you are running the alternator wayyy too hot (Alternator temp sensor installed and functional??)

Depending on the model used, we employ either avalanche or high voltage (400V) diodes in our builds. An Alternator protection module may help in this situation, but It would likely be a band-aid over an pre-existing issue.

Chris

Originally Posted by Mickeyrouse

I have used Balmar alternators about 15 years. I haven’t had to re-build them more than about every 100 hours, which is why I cruise with a spare. I have never had trouble with the regulators, but the alternator diodes constantly fry. I recently had them converted to “ single wire”, thus bypassing the external regulator and using the internal regulator. My alternator repair guy says that makes it a Delco alternator now, which is fine as long as it is more reliable. It has been, and if I have to replace it a Delco-type replacement is about $109 at Autozone.

[OS2Dude]

What is the size of your battery bank, and what type of batteries does it have? I recently replaced our OEM Motorola 51A with a J&N 105A alternator to meet the capacity of our two 98Ah AGM batteries. (For AGM batteries, an alternator should put out about 40% of the bank capacity. Lithium I believe requires an even higher percentage. You can damage an alternator if the batteries draw too much while charging.

[Statistical]

Originally Posted by OS2Dude

What is the size of your battery bank, and what type of batteries does it have? I recently replaced our OEM Motorola 51A with a J&N 105A alternator to meet the capacity of our two 98Ah AGM batteries. (For AGM batteries, an alternator should put out about 40% of the bank capacity. Lithium I believe requires an even higher percentage. You can damage an alternator if the batteries draw too much while charging.

AGM really prefer hard charging so yes 0.4C rate is ideal. Lithium doesn't really care. It will charge slow or fast (up to around 1C for most cells sometimes 2C).

With lithium though you need a "smart" externally regulated charger because sustained charging power can be very high for a very long time and dumb internally regulated chargers will often cook themselves. Technically you could do this on a lead acid battery if you had a really huge bank like 1000 Ah but most people don't have a big enough bank for it to be an issue.

[CarlF]

For a tranatlantic trip you need redundant reliable and redundant charging to be sure you can make water and drive the autopilot.

I'd upgrade to a serpentine belt and the Balmar XT 170 alternator. These have spacial windings that are not as prone to overheating. A standard alternator will lose half it's amp output after about 30 minutes. The XT170 will keep putting out close to rated power indefinitely.

[Keysrock]

I have a 150:amp brand new alternator for sale $400 plus shipping

[mroc]

Just went through the electrical major redo on my Bene 331 with the original 50A Hitachi alternator that was completely insufficient for cruising and hooked up poorly (to the start battery) with ACR between house and start. All issues are clinical symptoms of original factory setup described and diagnosed in "marine-how-to" web site that gave me great hints and made it possible to carry out work myself.
I went with Balmar 120A and a M618 external regulator. I did serpentine belt conversion as well, even though I was not convinced that a regular V-belt would be a problem. I was a bit shaky to do the wiring, but Balmar phone support was excellent and held my hand in developing a schematic to marry existing wiring with new stuff. I am very pleased with the product and end results. When needed (the regulator decides), at slow rpm the alternator delivers 100A with no questions asked. And you can see it (and pretty much all other alternator/battery parameters) on your iPhone. Programming of M618 regulator is a snap, again on your iPhone.

And yes, it is all expensive, but looks quality and gives you confidence on the water.

I highly recommend.

[SjoJungfrun]

I upgraded to the serpentine kit and tried the use a Hitachi like drop in. It last a few months and literally smoked up. Cheap alternators; you get what you pay for. Now have a XT170 + MC618 regulator almost installed. Marine How To website (Rod Collins aka MaineSail) is very helpful in educating on alternators, proper wiring and regulator setup.