Author Topic: shovelhead charging question  (Read 466 times)

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Offline roadkingdresser

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shovelhead charging question
« on: June 30, 2020, 05:37:16 AM »
 I've got a 66 flh, I put the alternator setup on it yrs. ago. couple yrs. ago I put the headlight from a r-king with the h4 bulb in it. Hardly ever run it after dark but the other evening I did and the next day went to start it and the battery was dead. charged it all day and started put the ohm meter on it. battery said 13.43 started and idled up went to 14.30 turned the light on and it dropped down to 12.7 and wouldn't go any higher. any input into this. thanks
roadkingdresser

Offline Racepres

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Re: shovelhead charging question
« Reply #1 on: June 30, 2020, 06:11:54 AM »
Your charging system cannot keep up with your Light or Lighting Circuit... tho 12.7 should Never drain yer battery a bit... maybe with "other" "Potty mouth" on, especially brake lights and turn signals ...it probably continues to Fall..
I know exactly Nothing about a generator conversion to Alternator... so... No Help there... but I cannot believe a halogen headlight can drain a Reasonable system..temporarily install a Good ole Wagner and test again... as I suspect a Wiring Problem!!!

Offline JW113

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Re: shovelhead charging question
« Reply #2 on: June 30, 2020, 08:26:41 AM »
The alternator conversions put out about the same amount of current (18A) as the stock gene, but start doing it at a lower RPM. I've used a couple of them, have one on my ironhead right now. I don't know how much power the H4 bulbs use, I did not think it a lot more than standard incandescent, but then I have no idea. They do get pretty damn hot, so maybe more power. If it's more headlight output you're after, maybe an LED Daymaker? They're less power than any other type of headlight.

One thing to keep in mind about any HD alternator charging system. They are all permanent magnet shunt regulated systems, meaning the alternator creates voltage/current no matter what the load is, the faster the alt spins the more juice it makes. The regulator monitors the system voltage and shunts (i.e. shorts) power to ground to keep the voltage from going over about 14.4V. I mention this, because part of the design of the charging system includes the lights being on. If you ride around a lot with the headlight off, which is an intended load on the system, then the regulator has to take up the slack and runs hot. This will shorten the life of the regulator, which in time can fail, then no regulation, the system voltage will rise quite high (18-20V), and take out the battery. Seen it happen several times, pretty impressive how the battery blows up like a balloon and can eventually crack.

Generators tend to not have this problem, as they use a field coil to create the magnetic field (instead of magnets), and the regulator modulates the field to control the generator output.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline roadkingdresser

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Re: shovelhead charging question
« Reply #3 on: June 30, 2020, 08:50:30 AM »
I don't run the headlight all the time just at night and the only other is the light bar on the rear that runs with the head light. I had generators on before, but with the 93" they don't like the higher rpm's. that's the reason I went with the alt. had to replace the voltage reg. 1 time. Might try a led in it but not sure it will fit in the bucket.
roadkingdresser

Offline JW113

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Re: shovelhead charging question
« Reply #4 on: June 30, 2020, 08:52:48 AM »
I kinda sorta recall there's a few making LED "H4" replacement bulbs. Never tried one yet though.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline Burnout

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Re: shovelhead charging question
« Reply #5 on: June 30, 2020, 09:11:53 AM »
LED lights are the way to go, however....

An LED bulb in a H4 fixture is not DOT approved, This means that light scatter and and light emmitted above the cutoff line may blind oncoming traffic!
Yes you can see somewhat better but a lot of light is wasted instead of focused on where you need to see.

The projector type fixtures (like a day maker) fix this problem.

To check your light aim it at a wall on low beam and you should see a sharp cutoff line, and as you roll the bike back from the wall that cut off line should lower.
This will show you that your light is a good design and is correctly aimed.
Any light above the cutoff line is both wasted and in oncoming traffics eyes. Light to the side or on the ground is wasted.
They don't call me Ironhead Rick just because I'm "hard headed"

Offline JW113

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Re: shovelhead charging question
« Reply #6 on: June 30, 2020, 10:47:49 AM »
An LED bulb in a H4 fixture is not DOT approved,

Hey, that means it will go great with my exhaust system!
 :SM:

All true as stated regarding light focusing and management. After thinking more than a second on this, LED bulbs won't work in the case anyway. Sealed beam on an old FLH, right? Need a whole LED headlight assembly to replace the sealed beam. Not cheap, but likely worth it in the long run.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline cheech

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Re: shovelhead charging question
« Reply #7 on: June 30, 2020, 11:40:12 AM »
 :scratch: If you put the Alt conversion and the H4 headlight in years ago and didn't have problems until now. Why go about and change the setup?
Clearly a issue has developed, weather wiring, bad regulator, Alt., battery.
You load test battery?
You never mentioned how old it is.

Offline JW113

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Re: shovelhead charging question
« Reply #8 on: June 30, 2020, 11:46:46 AM »
He said he hardly ever rides it with the headlight on after dark, but did recently. Still does not make sense, the alternator should have no problem keeping up with the lights on at anything other than at idle. The headlight can't draw more than 5 or 6 amps, the coil about 3 amps, the rest of the lights a couple amps. If the alternator puts out 18A @ 2000rpm, which I believe they do, plenty of power to recharge the battery if it's no at idle and ridden for a while.

Or... something is wrong somewhere.
 :doh:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline cheech

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Re: shovelhead charging question
« Reply #9 on: June 30, 2020, 12:19:22 PM »
Still does not make sense, the alternator should have no problem keeping up with the lights on at anything other than at idle.
Or... something is wrong somewhere.
 :doh:

-JW
:agree: To both of those.
RKDresser, how is the condition of the wiring btw?
That's a old dog. :SM:

Offline Hossamania

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Re: shovelhead charging question
« Reply #10 on: June 30, 2020, 12:42:20 PM »
My standard question, how old is the battery? After charging it, is the voltage?  What is the voltage after sitting for a while? What is the voltage after sitting for a day?
When borrowing money from a friend, decide which you need most.

Offline david lee

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Re: shovelhead charging question
« Reply #11 on: June 30, 2020, 03:09:12 PM »
My standard question, how old is the battery? After charging it, is the voltage?  What is the voltage after sitting for a while? What is the voltage after sitting for a day?
i agree.ive charged a flat battery thinking the battery is good. took a charge started the bike. next day dead again. my mate replaces his batteries every 3 yrs even if their goog

Offline roadkingdresser

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Re: shovelhead charging question
« Reply #12 on: June 30, 2020, 05:03:15 PM »
I've rewired the bike with a new harness. Was fooling with it today checking a few things with the switch on and the head light out of the bucket. After a few starts the battery was low. got it on a trickle charge now will be up in the morning. I'm thinking maybe a new batterty. Trouble is i only ride this thing in the spring for a couple 100 mile and then put it back on the charger. So is it worth a new battery? AHH I'll probably spring for it. Trouble with those old bikes, can't ride all 4. It is what it is. I just want it to go when i'm ready!
roadkingdresser

Offline JW113

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Re: shovelhead charging question
« Reply #13 on: June 30, 2020, 06:27:59 PM »
A good traveling musician friend of mine has a pal out in the boonies in northern Arizona. He has perhaps 50 old cars and trucks on his property. And only one battery!! He keeps one of those Union 76 orange antenna balls on the one with the battery so he can find it, and just moves the battery around from car to car. I think he does the same thing with the only set of up to date license plates.

Ah... living life on the edge!

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline cheech

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Re: shovelhead charging question
« Reply #14 on: June 30, 2020, 08:15:23 PM »
I've rewired the bike with a new harness. Was fooling with it today checking a few things with the switch on and the head light out of the bucket. After a few starts the battery was low. got it on a trickle charge now will be up in the morning. I'm thinking maybe a new batterty. Trouble is i only ride this thing in the spring for a couple 100 mile and then put it back on the charger. So is it worth a new battery? AHH I'll probably spring for it. Trouble with those old bikes, can't ride all 4. It is what it is. I just want it to go when i'm ready!
:up:
If it's a wet battery it isn't dry is it? I've had tenders dry up wet batteries before, I know they're not supposed to.  :scratch:
Worth a new battery? Nope, you should allow me to buy it.  :SM:  :idunno:

Offline roadkingdresser

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Re: shovelhead charging question
« Reply #15 on: June 30, 2020, 10:48:54 PM »
nope it's a gel.
roadkingdresser

Offline JW113

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Re: shovelhead charging question
« Reply #16 on: July 01, 2020, 08:34:27 PM »
I'm with Hoss. How old is it? 3-4 years? Garbage. Replace it.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline drifter

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Re: shovelhead charging question
« Reply #17 on: July 01, 2020, 09:50:57 PM »
To JW's reply #13
When my uncle was in high school in the late '20s he had a car (can't remember what kind now) in southern NH.  In the winter he had a coupe body on it and changed it to a roadster body for the warm weather.  Just a few mounting bolts and wiring connections, life was simpler then, until the cops got wise and made him choose only one.  He has been gone now for 30 some years but was always a bit wild.
« Last Edit: July 01, 2020, 10:08:38 PM by drifter »

Offline roadkingdresser

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Re: shovelhead charging question
« Reply #18 on: July 02, 2020, 08:49:38 AM »
well don't think the battery is the problem. charged overnite 13.51 @ 7:00   13.34@2:15  13.29@5:30 and 13.29@ 11:30 find out tonight goin for a nite ride.
roadkingdresser

Offline JW113

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Re: shovelhead charging question
« Reply #19 on: July 02, 2020, 08:53:08 AM »
Holding a charge with no load does not mean the battery is good. Hold old is it? Batteries tend to "sulfate" over time, no fixing it once that happens.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline Racepres

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Re: shovelhead charging question
« Reply #20 on: July 02, 2020, 08:58:12 AM »
Holding a charge with no load does not mean the battery is good. Hold old is it? Batteries tend to "sulfate" over time, no fixing it once that happens.

-JW
Very true... But a meter on it when a load is on it, is indispensable..or a load test... Some Batteries last a year or two... the next one, same brand etc... will last 5 or 6 years... have a friend who had one last even longer... he Kinda Babied it along tho.. I absolutely ignore Mine, and generally I get 2 or 3 years

Offline david lee

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Re: shovelhead charging question
« Reply #21 on: July 02, 2020, 02:40:54 PM »
my mate whos a mc mech said 3 yrs out of a battery your lucky.there not what they used to be