Charging system......again

[Paniolo]

As many of you know, I am tied with several members in the "Stator Replacement" catagory. With colder temps approaching, I am leery about using my heated grips, and heated jacket liner for fear of overloading the electrical system and frying another stator. So today I hooked up a multimeter to the battery and took some readings. Here are my findings.

12.61 Right off the battery, bike not running.
11.73 Ignition on.
14.10 Bike running at idle.
14.07 Spot lights turned on.
14.02 Hi Beam turned on.
14.00 Heated grips set to maximum.
13.02 Jacket liner set to maximum.
13.09 Jacket liner set to low.
12.99 Jacket on max, grips on max, spot lights on, high beams on, bike at idle.
14.00 All of the above, bike at 2000 rpms.

What say you the electical gurus?
Is the system working as it should, or am I overloading it?

Mark

[Billy]

Not a guru but it looks ok to me.

Do you have a 38 or 45 amp system?

[RoadKingTrooper]

Mark, your numbers look OK, I don't know that the load matters as much as the field winding condition. If I recall correctly the alternator is constantly charging and excess power is shorted through the voltage regulator to ground (frame). That is why the regulator consists of a large heat sink around it.
Someone correct me if I am wrong please.
Scot

[HIPPO]

Your bike is a pre 02?

A shunt system always works at full output. If you overload it all that happens is that the battery eventually runs down. What it doesn't use goes to ground dissipated in the form of heat at the regulator.

Heat shortens the life of these things. In a way slow riding as during instruction where there is a lot of heat in the primary from heavy clutch use in the friction zone is hard on them. This would also apply to the series systems.

[JBarrettB]

The amp output is key. When it is all said and done you need 3.5 amps free to charge the battery. A charging system is considered good if its actual amp output is 85% of its amp rating. To many accessories and the battery may not maintain its state of charge. Harley systems in the past have had the brake even point, the point where charging system output exceeds the electrical goodies amp consumption, above idle rpm. So the more accessories you power the higher the brake even point is in terms of rpm. This is one major reason for the 38 and then the 45 amp output systems. I can't say with certainty but I suspect that the brake even point of these newer higher output systems is closer to if not below idle rpm.

JB         

[Paniolo]

So if I overload the system, it will drain the battery. Once the battery is drained, will it move on and fry the stator?
The bike is an '01 Ultra with the 45 amp charging system.

Heat, (like my running across the Mojave at 118 degrees for four hours at 85mph) may have been a contributing factor to my last couple of failures.
That coupled with my excessive Enforcement Style Riding which may overheat the primary oil. Did I get that right too?

Mark

[Rydr2]

The voltage readings looks really good at idle speed.   And you have a 45amp system, you're good to go.

[HIPPO]

Mark,
Yes, IMO is is a heat related issue. Probably cumulative, ie one time running hot isn't going to kill it but high temp over time burns the lacquer insulation on the stator off. The rodeo style riding is likely much harder on it then running 85 through the desert, I do that all the time.
Like a steak on the barbie, 3 min a side rare, 20 min a side charcoal.
I feel the reason I never burned one in almost 200K miles on two bikes, a 99 and a 02, other then luck is that I set them up with very positive clutch engagement, primary chains on the loose side of spec and run MTL that transfers heat well. Also the engines are set up to run as cool as possible.
Not one thing, just a couple degrees here and a couple there and pretty soon you are talking a difference.

Once it drains the battery nothing further happens. Most likely though you would find that the bike at some point would crank slow or not crank. Typically it takes a while of riding to recover from a cranking event. If charging is not sufficiently in excess of consumption at some point it will not crank because instead of recovering charge it falls more and more behind.
It would take a very significant deficit to kill the bike while running between fill up's, this is the mode when it already went TU.

[Paniolo]

Thanks for all the tips guys. I keep the bike on a smart charger so it's always topped off. I guess the best test I can do is pop the derby cover off every once and a while and smell for fried wires.

Mark