Just bought my second Alternator in 18 months. (100 to 200 hrs.)
I took my Alternators to the rebuilder and he told me that heat was killing my Alt. Plus its a cheap piece to begin with! Not worth his time to fix.
Mistake #1
I bought a Cheap 51 Amp Alternator to charge a 440 amp hr. battery bank.
Mistake #2.
Running batteries down to about 60% SOC (about two days on the hook.
Mistake #3.
Run engine/Alt. for about 4/5 hours at Max output of Alt. 40-45amps. Every 2nd day (maybe 1200 RPM)
Mistake #3 didn't run blower to cool Alt and engine compartment.
See attached pic of cheap internet $200 Alt. Motorola look a like.
Lessons learned:
1.Cheap Alternators are really not designed to charge batteries for hours on end at high amps.
I certainly see why people spend the money on a higher output Balmar! Take a look at the picture of my cheap Alt, then look at a Balmar. Much more cooling vents.
2. I should have run the engine each day at a lower output, maybe 35 amps. (Less heat)
3. Run the blower and ensure the hose is pointed at the Alt.
4. On the last day of a Island trip, being down a 200 amps. Just start the engine on the start battery and motor/sail home on the start battery. Once back in the slip, use the shore charger during the following days to bring the bank back up. Saves were and tear on Alt. and saves HP.
5. Going solar!
Chuck Lennox
97 MKii Ventura Ca
Island Girl Hull #1611
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[quote=clennox]
Just bought my second Alternator in 18 months. (100 to 200 hrs.)
I took my Alternators to the rebuilder and he told me that heat was killing my Alt. Plus its a cheap piece to begin with! Not worth his time to fix.[/quote]
These Chinese cheapos really are not worth the time to fix nor to buy or install even once, but some will certainly disagree. (wink)
[quote]Mistake #1
I bought a Cheap 51 Amp Alternator to charge a 440 amp hr. battery bank.[/quote]
Properly set up (external regulation, temp sensor and current limited) a 51A alt can certainly charge that bank but at nowhere near 51A. More like 20-25A with that type of alt which will take a very, very, very long time. The actual Leece-Neville version of that alt is significantly better constructed and may be able to do 30A...
[quote]Mistake #2.
Running batteries down to about 60% SOC (about two days on the hook.[/quote]
There is no mistake here just a poor choice of alternator. Heck run your bank to 50% SOC but you'll need a way to charge it that won't kill itself..
[quote]Mistake #3.
Run engine/Alt. for about 4/5 hours at Max output of Alt. 40-45amps. Every 2nd day (maybe 1200 RPM).[/quote]
With no way to current limit an alt like this anything beyond the first 10-15 minutes and the alt is cooking hot and life is being shortened...... 4-5 hours in bulk is just not a reasonable expectation from a cheap Chinese knock off automotive alternator.
[quote]Mistake #3 didn't run blower to cool Alt and engine compartment.
[/quote]
While the blower can certainly help it was not going to save this alt. The only thing that would have saved it was limiting its output to 20-25A then adding a temp sensor on top of that limited to 220-230F...
[quote]Lessons learned:
5. Going solar!
[/quote]
Solarcan help but not all that much if you are down 200Ah's in two days, unless you have a very large unshaded array. You'll still want a good solid source for bulk charging....
-Maine Sail
https://www.marinehowto.com/
I'm glad Marine commented on this issue. I think so many people out there buy these internet Alts. The PO of my boat was happy that he bought a "New Alt" For less than have the old one rebuilt. Now that higher quality Alt is gone.
I don't think putting a external reg is even doable on these cheapies, A 25 AMP charging rate will take a while for a large bank
I just bought 200 watts of solar and a Honda 2000 for my two week trip to the islands.
Chuck Lennox
97 MKii Ventura Ca
Island Girl Hull #1611
If your doing trips, a Honda EU2000 works great and fits nicely in the cockpit locker. Hook it to my ProNautic 40amp and it runs in econo mode. When we go ashore, I kick it on and my batteries are fully charged when I get back.
Under sail, my wind generator is able to keep pace with my fridge and electronics.
my engine has a lot of hours on it (3150) and i feel that the reason it has lasted so long is that the PO used an EU2000 to charge the batteries. When I run it, it's nearly always at 2200 to 2500 RPM with occasional 1800 RPM motor sailing. Never with no load like charging batteries.
2000 C36 MKII 1825
May I also suggest the Electromaxx line of alternators. I bought the 100 amp cruiser one and was so happy with it and the support, I sold my balmar MC614 voltage regulator (perfect working order) and bought Electromaxx's new charge control system. I find the alternator runs much cooler and produces much many more amps at a much lower RPM. I cruised New England with it all summer and found myself only charging batteries once a day for about 45 minutes at most (depending on kids electronics usage). I have a 350 amp AGM house bank and cycle between 50% and 80%. Any more charge is a waste of fuel and sound. Their new charge control system will allow me to monitor the efficiency and coorilate it to RPM so I know when I am going down a path of deminishing return and what the most efficient RPM is. To get the 100 amps I also installed the serpentine belt kit which took no time to install. One word of warning is to check the clearance between the belt and the raw water pump bleed screw. I went through 2 belts (should last a long time) before realizing what it was. I ended up cutting the head of the screw down to gain some extra clearance.
Matthew Schubert
S/V Mary Lynne #436
Annapolis/Newport
1985 C-36 M25XPB
[quote=mschubert]May I also suggest the Electromaxx line of alternators. I bought the 100 amp cruiser one and was so happy with it and the support, I sold my balmar MC614 voltage regulator (perfect working order) and bought Electromaxx's new charge control system. I find the alternator runs much cooler and produces much many more amps at a much lower RPM. I cruised New England with it all summer and found myself only charging batteries once a day for about 45 minutes at most (depending on kids electronics usage). I have a 350 amp AGM house bank and cycle between 50% and 80%. Any more charge is a waste of fuel and sound. Their new charge control system will allow me to monitor the efficiency and coorilate it to RPM so I know when I am going down a path of deminishing return and what the most efficient RPM is. To get the 100 amps I also installed the serpentine belt kit which took no time to install. One word of warning is to check the clearance between the belt and the raw water pump bleed screw. I went through 2 belts (should last a long time) before realizing what it was. I ended up cutting the head of the screw down to gain some extra clearance.[/quote]
It is good to hear a happy report from an E-Maax customer. I know my article has sent them a ton of business but that one article has also resulted in 98% of the negative/unhappy comments on my web site.
I am almost to the point of yanking that article, or removing E-Maax from it, but for now I have just added some strong cautions around customer service. I know John and Rob can get there shite together, but apparently, according to my readers, they have dropped the ball a bit... I have personally had good service from them but I know from the comments some have not...
-Maine Sail
https://www.marinehowto.com/
I too read the bad feedback from your article regarding them but I thought I would atleast talk to them and give them a shot as they in theory provided everything I wanted. That said, I did have a shipping issue once with them where I was promised a delivery by a certain date and a day before hand it had not been shipped. My due diligence in checking up with them paid off as they shipped it overnight (crazy expensive for them). I have brought up the negative feedback they have had to John and he has said they have been working very hard to devote the time, money, and energy to turning that around. He said it was a byproduct of the allocation of there time to develope the products.
I have so far loved their product and believe in their goal. I will be chatting face to face with John at the Annapolis boat show and will bring this up with him. They are on the verge of releasing some really cool hardware and software for their charge manangement system which I hope to try out.
Matthew Schubert
S/V Mary Lynne #436
Annapolis/Newport
1985 C-36 M25XPB
[quote=mschubert]I too read the bad feedback from your article regarding them but I thought I would atleast talk to them and give them a shot as they in theory provided everything I wanted. That said, I did have a shipping issue once with them where I was promised a delivery by a certain date and a day before hand it had not been shipped. My due diligence in checking up with them paid off as they shipped it overnight (crazy expensive for them). I have brought up the negative feedback they have had to John and he has said they have been working very hard to devote the time, money, and energy to turning that around. He said it was a byproduct of the allocation of there time to develope the products.
I have so far loved their product and believe in their goal. I will be chatting face to face with John at the Annapolis boat show and will bring this up with him. They are on the verge of releasing some really cool hardware and software for their charge manangement system which I hope to try out.
[/quote]
I used to send the bad notes to John then I just started deleting the outright nasty ones. What you see on the site is a small fraction of the complaints I have received. John knows about many of them but these days I just delete the nasty ones as I figure he already knows what has transpired.. It is good to hear they acknowledge this and are working on it... Sadly, in the process, a number of good installers and dealers moved on...
-Maine Sail
https://www.marinehowto.com/