Alternator upgrade and using Internal Regulator

[pablosgirl]

Hi All,

I have recently been afforded the opportunity after working for a company for 18 years (layoff & severance) to take a 6 month cruse.  We plan to go from Texas to the Bahamas (1200 miles one way).  Anyway we are preparing the boat for the trip. 

Up until this time we were weekend sailors with the boat in the slip tied to shore power during the week.  We would take a one to two week cruse once a year which would involve only a night or two not on shore power.  The boat had the stock 55 AMP alt with a Spa Creek AutoMack and 2 6v golf cart batteries delivering 190AH.  This was fine for our weekend cursing pattern.   

Now with the extended cruse coming, we did an energy budget and found that 110 AH would be our average 24 hour load.  Most of this is the fridge in the tropics.  Not wanting to discharge the house bank deeper than 50% and have a margin of error we decided to add two more 6v batteries to double the house bank capacity to 380Ah.  We purchased 4 new batteries since the original 2 were 4.5 years young and did not want to mix old with new.   Also realizing that the original Motorola alt is approaching 28 years in age and I did not want to rely on a 28 year old alternator putting out near max amperage using the AutoMac for nearly every day for six months to replenish a 380AH house bank. So I was thinking that if I needed a spare then I should upgrade to a higher amperage alternator that would shorten my charge time on a larger bank and use the old as a backup spare.  Unfortunately, time or budget dose not allow us to add solar as Waterdog did for his cruse.  So it will be a new alt and a Yamaha 2K Genset to keep the batteries charged to at least 80%.

The new L-N was $225 with shipping, great piece of mind if you ask me. Also, I did not want to go to the expense of adding a Balmar or similar external regulator.  As Mainesail suggested, I think it is overkill for my use.  We plan to use the Intercoastal water way to get to Florida which could involve a lot of motoring.  Once we get to the Bahamas, we plan on using the techniques spelled out in "The Gentleman's Guide to Passages South: The Thornless Path to Windward" by  Mr. Bruce Van Sant and this may involve some amount of motor sailing too.

So the question is how do I wire in the new alternator, using its internal regulator and achieve the 14.4 volt sensed bulk charge stage that Mainesail mentions is possible with the internal regulator on the L-N.   I have been reading the "Electrical 101" topics but I did not find a great amount of detail on using the internal regulator.  Looks like most skippers chose the external regulator option.

Currently the alternator output is attached to the starter post which connects through the "C" post of the battery switch.  I plan to remove the wire between the AO and the starter post and add a #2 red wire from the AO to the house bank which has a 100A fuse currently.  Do I need to increase the fuse amperage?  I plan to add an additional #4 ground wire from the alt ground to the house bank.  I thought of adding an additional #4 ground wire from the alt to the engine ground point.  Is this necessary?  Now the tack will connect to one of the two AC taps on the alt. 

My concern is that I have missed any additional wiring requirements and how the voltage drop between the alt and the house bank will affect the bulk charge phase since the internal regulator is sensing the voltage at the alt and not the house bank.  Can I take the sensing leads of the internal regulator and extend them to the house bank terminals like external regulators do and achieve a proper bulk charge phase?  OR... I believe there is a POT on the back of the internal regulator on the L-N that sets it's absorption voltage LIMIT?  Can I merely calculate the voltage drop and set the POT to a higher voltage, say 14.6v to compensate for the voltage drop? I plan to keep the AutoMac physically installed in the boat but with the wiring not connected but laying in wait in case it is needed.

I will continue reading the "Electrical 101" pages, any suggestions would be greatly appreciated.

Paul Shields

[tgsail1]

Paul-   Mainesail wrote this up on another post just the other day. http://c34.org/bbs/index.php/topic,8803.15.html- page two, last post as of today. He learned something I had not known, but was confirmed by L-N, that the red sense wire on the adjustable regulators is also the power supply for the ~5A regulator excitation circuit. That means that you can use the red wire and black wire on the two outputs (+-B) to remote sense the voltage, but there will be a drop along that line from ~5A max current, so the remote sense wire needs to be properly sized to minimize that drop. The recommended max drop of 1% will likely push you to 8-10 GA wire for sensing.

An interesting aspect of this configuration is that the regulator will now be sensing a slightly lower voltage than that of the battery when charging at high current, so the switch from bulk to absorption will occur a little later- so it might be wise to adjust the absorption voltage down a bit to compensate. I'd leave it to Mainesail to comment on that.   

[KWKloeber]

What amperage is the new LN?  You need to calculate voltage drop in the cables and size accordingly (INCLUDING negative cable) at the higher alt output.  Negative connection should be to the starter motor mount tab, not to the bell housing, and add an appropriate size cable to the alternator ground frame, don't rely on the engine/bracket for ground.  Size the sense wire for max 1% (OR LESS) drop, 5amp current.

kk

[pablosgirl]

Hi KK,

The alternator is a Leece-Neville 90 AMP model 8MR2069TA.  This is the one that Mainesail features in a number of his how-to articles.  I just want to use the internal regulator.

[mainesail]

Hi All,

I have recently been afforded the opportunity after working for a company for 18 years (layoff & severance) to take a 6 month cruse.  We plan to go from Texas to the Bahamas (1200 miles one way).  Anyway we are preparing the boat for the trip.

Up until this time we were weekend sailors with the boat in the slip tied to shore power during the week. We would take a one to two week cruse once a year which would involve only a night or two not on shore power. 

^^^^^^^Perhaps overkill for this described use ^^^^^^^

As Mainesail suggested, I think it is overkill for my use.

An external regulator is really not overkill for this use. Battery & alt temp compensation, belt manager, soft start and a proper 14.6V - 14.8V absorption voltages for GC2's then a drop to float, on those long motors, are all right where an external regulator fits. Staying at a 14.4V absorption is a compromise that can work but for your described use is less than optimal.

We plan to use the Intercoastal water way to get to Florida which could involve a lot of motoring.

[pablosgirl]

Hi Mainesail,

Thanks for the response.  I would like to purchase a "smart" external regulator, but the cruising kitty budget is now at the point if I spend to much more on boat stuff I will have to cut my cruising time short.  Not an optimal situation.  I would like to utilize the equipment that I have as best I can.  Is it worth moving the sense wires off the Leece-Neville 90 AMP model 8MR2069TA internal regulator and connecting them to the house bank or is this not going to buy me much? 

I have been looking for a used Balmar external regulator to no avail.

Paul Shields

[Craig Illman]

I picked up a new Balmar ARS-5-H off eBay last fall for about $100 off market price. Another place to check periodically if you're not in a rush.

[mainesail]

Hi Mainesail,

Thanks for the response.  I would like to purchase a "smart" external regulator, but the cruising kitty budget is now at the point if I spend to much more on boat stuff I will have to cut my cruising time short.  Not an optimal situation.  I would like to utilize the equipment that I have as best I can.  Is it worth moving the sense wires off the Leece-Neville 90 AMP model 8MR2069TA internal regulator and connecting them to the house bank or is this not going to buy me much? 

I have been looking for a used Balmar external regulator to no avail.

Paul Shields

Measure your voltage drop at max output by using an inverter and hair dryer (inverter load should exceed alt capability by at least 10%) to force the alt into full field then measure the voltage at the back of the alt and then at the battery terminals. Also verify voltage drop across the positive and negative sides of the circuit. That will tell you if moving the sense wires is worthwhile. 9 times out of 10 it is. Accurate sensing can improve short duration charging performance by 10% to 30% + depending upon how bad the voltage drop is.

[Ron Hill]

Paul : Here's an analogy of what you are doing with your new alternator.
"You just bought a new hi performance engine, but only want to use 85 octane fuel in it!!"

Look at all of the benefits (Mainsail listed them) that you'll gain from a smart external Volt regulator!!

Don't be "pound foolish"     My thought 

[pablosgirl]

I have been trolling ebay and found a listing for "Leece Neville/Balmar MC-614-LN Marine Regulator - 12V".  It looks like a Balmar 614.  Does someone else make these for Balmar and they can be branded by different distributors?  I might be able to swing $85 if this is not a cheap China knock off.

Paul

[mainesail]

I have been trolling ebay and found a listing for "Leece Neville/Balmar MC-614-LN Marine Regulator - 12V".  It looks like a Balmar 614.  Does someone else make these for Balmar and they can be branded by different distributors?  I might be able to swing $85 if this is not a cheap China knock off.

Paul

Balmar makes regulators for Xantrex and Leece-Neville. That is basically a hybrid and closer to a 612 than an MC-614 but at $85.00 is a very good deal if it works. Leeve-Neville has been a Balmar partner for years and still builds some Balmar's large frame alts..

[Noah]

At $85 does it include a wiring harness?

[mainesail]

At $85 does it include a wiring harness?

If not it is very easy to make your own with insulated .250 Fast-On terminals. You could always buy a harness from Balmar too...

[KWKloeber]

I have been trolling ebay and found a listing for "Leece Neville/Balmar MC-614-LN Marine Regulator - 12V".

Paul

Cripes, for the cost of these appurtenances, I would have expected to see a "complete sealed box" -- like a shore charger -- with a cover and pass thru grommet with internal connections???  Or external connections with God forbid a strain relief for the wiring.   

Not a slab of aluminum channel filled with components and epoxy with exposed tabs and a name slapped on it.   They look like a Junior High science fair project.  What am I missing?  Expectations too high?   

Junior High - now I'm showing my gray.   

kk

[pablosgirl]

Hi Mainesail,
Does the LN internal regulator have a "soft start" feature?  I noticed on start up in the morning after being on the hook all night with the fridge and anchor light burning all night, that the volt meter in the engine panel showed about 12.5 volts after starting the engine. The voltage then slowly increased to 14 volts after about 15 min.  Is to be expected?

Paul