alternator replacement E34

Hey, everybody just calm down.

All, Lets all take a big deep breath and remember what it's like to be on our boats, close hauled on a warm sunny day in the middle of summer. After all that's what this list is really all about.

On another note, I was standing in line at my local Starbucks on Sunday morning when in walked Careem Abdul Jabbar AND Sugar Ray Leonard and both stood right behind me. Yeah, I ended up having cream & sugar with my coffee. Glyn Judson, E31 hull #55, Marina del Rey, CA

> Can expand on your post a bit?

I had thought his point would be that you have to look at both float voltage and float current to assess whether or not the battery is going to get boiled out. Heat = energy = volts x amps, can't tell one without the others.

But I'm not sure.

Float mode

tenders - In the float mode the voltage is kept low enough that you can not put enough energy into the battery to hurt it. It is for long term maintenance, not charging. A single stage charger (or regulator/alternator) doesn't have a float voltage. The voltage is kept at about 14.0 volts or higher. The Leece Neville adjustable regulator adjusts this voltage at 14.0 to 14.2 volts. There is no float voltage.

A three stage charger's float voltage is ~13.5 volts.

A single stage charger has to have a compromise voltage that will not cause much heating of a charged battery, and will still charge a discharged battery. It is a compromise, and does not do either job as well as a proper three stage charger.

That said, you do not need a three stage regulator or a large alternator unless you need to replace a lot of energy in a relatively short period of time. For example, an anchored boat with refrigeration.

A single stage charger on 24/7 on shore power will shorten a battery's life.

God I love this site

Leece Neville sez:

Maine Sail - I got my info from their site, but before going there, the simple explanation is that you are not in float mode condition. The load current on your XBM would indicate that the alternator is load limited at it's present rpm. Your alternator should put out full voltage at 11 amps at cruising rpm. Engine 2500 rpm - alternator 5000 rpm.

In simple words, your setup has a problem or you are not operating how you think you are.

Looking at the Leece Neville test stand guide:

http://www.prestolite.com/literature/tech/alts/TSB-1018_Test_Stand_Flow.pdf

It says the voltage should be adjusted to 14.0 volts with no load and should drop no more than 0.5 volts at 75% of NP load and 3600 rpm. 3600 rpm is about 1800 engine rpm. If it can't do that "submit for warranty".


From: http://www.prestolite.com/pgs_support/trouble_shoot_1.php


"Leece-Neville alternators are equipped with one of two regulators. The Fully Adjustable Regulator has a flat cover plate. The Three Step Regulator has a finned, curved cover plate. Use the following test procedure that is appropriate for you regulator type.


Fully Adjustable Regulator


NOTE: Battery must be at least 95% charged prior to this procedure. Also make sure wire connections and belt tension are OK.


1. Shut off all electrical accessories and run the engine at approximately 1000 RPM.


2. Connect a voltmeter to the alternator outputs.


3. Remove the plastic screw from the regulator (see photo) and insert a small screwdriver in the hole. Engage the screwdriver blade in the slotted adjustment screw inside the regulator.

CAUTION: The adjustment potentiometer screw has high and low stops. DO NOT exert excessive pressure on the screwdriver or you may damage the regulator.



4. Turn the screwdriver clockwise to raise the voltage, counterclockwise to lower the voltage. Set the voltage between 14.0 and 14.2 volts (28.0 to 28.4 volts for 24-volt units).


CAUTION: DO NOT force the screwdriver past the set stops at either end of the adjustment range to avoid regulator damage.

5. Remove the screwdriver and voltmeter and install the plastic screw in the adjustment screw access hole."

BTW, the hated Balmar regulator is made by the same company as the loved Link 10 and XBM.

Yolanda....
Are you happy now??? )

Howard
Sea Quest
Berkeley

Lots to digest, Howard! And Nigel Calder as bedtime reading...

Thanks again everyone!

Jolanda