Alternator, I Think It Finally Works!

[NICK1951]

This has been a long journey. We keep a 1995 Benetau Oceanis 400 in Fajardo, Puerto Rico and sail the Spanish, US, and British Virgin Islands for 3 months each winter. We consume 80 amps, daily. The Engle cooler is responsible for 50 amps. We also, use engine driven Sea Frost refrigeration. The house bank is 400 amp hour AGM.

I had an ElectroMaxx 120 amp alternator and Balmar 614 regulator installed 3 years ago. Things went from bad to better. Still not best.

Main's post have been great!

My environment before reading Mains's posts was as follows:

Alternator voltage 15.5
Regulator sensed voltage 14.3
Regulator targeted voltage 14.4
Actual voltage to house batteries 13.4

This is what a non technical type did mostly under Main's direction:

1. Upgraded 4 awg wire to 1 awg wire for charging circuit.
2. Replaced 70 amp battery isolator with Blue Sea 7610 ACR.
3. Moved regulator ground from alternator to battery.
4. Removed wire from alternator D+ connected to ignition.
5. Installed 175 amp MBRF fuses on each side of the ACR.
6. Installed 200 amp MBRF fuse on battery from alternator B +.
7. Replaced 1 amp fuse in regulator sense wire.

Benefits:
1. .2 volts.
2. .8 volts.
3. Voltage sense became accurate previously, .2 volts under sensed.
4. This made the alternator use the external regulator instead of the internal regulator.
5 and 6. Safety precaution. I Plan to put a 300 amp fuse on the starting circut soon.
7. Fuse was blown. This fix sent an extra 1.1 volts to the batteries. Iguess I am sorta stupid.

Current environment:

1. During bulk charge, alternator 14.6, regulator sense 14.4 and batteries 14.4.
2. ACR truely combines batteries. Same voltage at house and start. Better for start battery.
3. Start engine twice a day when house voltage reaches 12.45. Typically runs for 40 minutes each time. Turn off engine, when ampmeter shows about 20. Amp meter starts at 70, runs mostly at 40.
4. Sea Frost refrigeration solenoid moved from alternator side of isolator to circuit breaker.

SPECIAL CAUTION FOR BENETEAU OWNERS!!!!!!

I have 4 on/off battery switches which control ground, start, house and
windlass circuits. The 1/0 wire between my start switch and the starter was seriously chafed against the lower lug on the ground switch. This is hard to see without taking numerous wires off the switches. I think I was lucky.

Thanks Maine.

Nick

 

[1andyw]

Impressive. Nice work!

 

[4arch]

I have a 93 Oceanis 400 and recently completed similar upgrades - beefed up the charging circuit wiring, got rid of the isolator, and upgraded to a Balmar MC-614 regulator. I’m still driving a stock 70 amp alternator that had previously been converted to external regulation. Even with the stock alternator, the 4 AWG positive charging cable had actually gotten hot enough at some point to melt the insulator boot to the positive stud on the alternator. So heavier cabling was definitely in order. I had to replace the entire stud and I also added a temp sensor to my MC-614. So far so good but need to wait for a spring thaw to really evaluate the performance.

Thanks for the tip on the battery switch wiring – I will check mine.

 

[Maine Sail]

I have a 93 Oceanis 400 and recently completed similar upgrades - beefed up the charging circuit wiring, got rid of the isolator, and upgraded to a Balmar MC-614 regulator. I’m still driving a stock 70 amp alternator that had previously been converted to external regulation. Even with the stock alternator, the 4 AWG positive charging cable had actually gotten hot enough at some point to melt the insulator boot to the positive stud on the alternator. So heavier cabling was definitely in order. I had to replace the entire stud and I also added a temp sensor to my MC-614. So far so good but need to wait for a spring thaw to really evaluate the performance.

Thanks for the tip on the battery switch wiring – I will check mine.

It is not the cable over heating it is your alt getting so hot because it simply can't handle those loads. Key words are "stock alternator".. These factory alternators simply can not handle those type of loads without being current limited in the regulator (Belt Manager) to at least 25% - 40% less than rated output...

You will want Belt Manager set at a level 4 minimum but possibly 5 or 6 plus the temp sensor set at 220F as a back up...

 

[Maine Sail]

This has been a long journey. We keep a 1995 Benetau Oceanis 400 in Fajardo, Puerto Rico and sail the Spanish, US, and British Virgin Islands for 3 months each winter. We consume 80 amps, daily. The Engle cooler is responsible for 50 amps. We also, use engine driven Sea Frost refrigeration. The house bank is 400 amp hour AGM.

I had an ElectroMaxx 120 amp alternator and Balmar 614 regulator installed 3 years ago. Things went from bad to better. Still not best.

Main's post have been great!

My environment before reading Mains's posts was as follows:

Alternator voltage 15.5
Regulator sensed voltage 14.3
Regulator targeted voltage 14.4
Actual voltage to house batteries 13.4

This is what a non technical type did mostly under Main's direction:

1. Upgraded 4 awg wire to 1 awg wire for charging circuit.
2. Replaced 70 amp battery isolator with Blue Sea 7610 ACR.
3. Moved regulator ground from alternator to battery.
4. Removed wire from alternator D+ connected to ignition.
5. Installed 175 amp MBRF fuses on each side of the ACR.
6. Installed 200 amp MBRF fuse on battery from alternator B +.
7. Replaced 1 amp fuse in regulator sense wire.

Benefits:
1. .2 volts.
2. .8 volts.
3. Voltage sense became accurate previously, .2 volts under sensed.
4. This made the alternator use the external regulator instead of the internal regulator.
5 and 6. Safety precaution. I Plan to put a 300 amp fuse on the starting circut soon.
7. Fuse was blown. This fix sent an extra 1.1 volts to the batteries. Iguess I am sorta stupid.

Current environment:

1. During bulk charge, alternator 14.6, regulator sense 14.4 and batteries 14.4.
2. ACR truely combines batteries. Same voltage at house and start. Better for start battery.
3. Start engine twice a day when house voltage reaches 12.45. Typically runs for 40 minutes each time. Turn off engine, when ampmeter shows about 20. Amp meter starts at 70, runs mostly at 40.
4. Sea Frost refrigeration solenoid moved from alternator side of isolator to circuit breaker.

SPECIAL CAUTION FOR BENETEAU OWNERS!!!!!!

I have 4 on/off battery switches which control ground, start, house and
windlass circuits. The 1/0 wire between my start switch and the starter was seriously chafed against the lower lug on the ground switch. This is hard to see without taking numerous wires off the switches. I think I was lucky.

Thanks Maine.

Nick

Glad you got it to work. Fixing bad alternator installations is something I do regularly and pos & neg power supply wires, isolators and voltage sensing would be three of the biggies I see violated most often.....

I don't know if you've seen this article yet but it deals with the voltage sensing issue you corrected......


Alternators & Voltage Sensing - Why? (LINK)

 

[NICK1951]

Belt Management

Maine,

I am curious, you suggested belt management set to 4 for stock alternators. Is a Balmar considered stock? If not, what belt setting do you recommend? I have a 1/2 inch cog belt that shows no dust or cracks. My belt managent is 1. Battery temp is at the top of the range, 40 c. Thanks for your help. I plan to make a contribution to your web site, when I get home. I could do it sooner, but I have spent all my money on ice.

Nick