Author Topic: Headlight drains battery (Read 9635 times)

StreetSpirit · « **on:** June 06, 2012, 10:24:14 AM »

As the title says, the bike seems to charge ok with the headlight off but as soon as I hit the switch I can see the battery voltage go from slowly climbing to rapidly falling. It will eventually kill the bike (as I found out in traffic last night on a shakedown ride). The wiring harness is kind of a mess but I did just clean the up the connectors and the problem remains. Have an electro sport regulator rectifier also.

I seem to remember reading somewhere that there was a second alternator coil that was only activated when the headlight came on. The bike came with an aftermarket headlight switch and I'm wondering if that might be my problem. Like maybe I need to wire in another switch for "fast charge" mode? Anybody have any insight?

strynboen · « **Reply #1 on:** June 06, 2012, 10:35:17 AM »

here are the most simpel diagram..it are not komplet right..but gives some ideas... if it are a sohc 4..engine

bollingball · « **Reply #2 on:** June 06, 2012, 10:35:22 AM »

No one will know without knowing what bike & motor.

flybox1 · « **Reply #3 on:** June 06, 2012, 10:48:49 AM »

we'll also need to know what headlight you are running. if its after market or stock and the rating.
have you done any mods to the electrical system, or any el. system maintenance in general?

StreetSpirit · « **Reply #4 on:** June 06, 2012, 11:38:18 AM »

Hah, sorry, 77 cb550f. Better add it to my sig or something.

Headlight is an h4 35/55 I'm pretty sure. New points, new lifepo4 battery, wiring is all hacked up by po and I've been going through and soldering/shrink wrapping as issues present themselves.

mono · « **Reply #5 on:** June 06, 2012, 11:45:24 AM »

i have a '75 550K and even after going through my whole electrical system and cleaning everything and ensuring everything was running at the right resistances, i still get a battery drain from the headlight. i have heard that "that's just the way they are", but I dunno if that applies to your specific model.

riding in the higher RPM range seems to help it stay charged, but that's hard to do in stop+go traffic.

i also removed my turn signal buzzer to reduce the power draw, but i don't know how much it helped.

Duanob · « **Reply #6 on:** June 06, 2012, 12:53:53 PM »

Sounds like you have a weak charging system for one reason or another. You need to do some diagnostics.

Start here: http://www.oregonmotorcycleparts.com/FAQ.html

flybox1 · « **Reply #7 on:** June 06, 2012, 01:03:20 PM »

Quote from: Duanob on June 06, 2012, 12:53:53 PM

Sounds like you have a weak charging system for one reason or another. You need to do some diagnostics.

Start here: http://www.oregonmotorcycleparts.com/FAQ.html

+1
Vreg might not be charging properly.
test your battery voltage in the following, and report back.
1. bike off
2. lights on, bike off.
3. bike idling lights on
4. 4000rpm

TwoTired · « **Reply #8 on:** June 06, 2012, 01:14:30 PM »

Standard bike electrical loading with lights on is about 120 Watts.

The max output from a good Cb550 charging system is 150 watts @ 5000 RPM, with about 1/3 of that at idle RPM. Any charging system shortfall against the electrical load, is made up with stored energy in the battery (until depleted).

How good are you with math?

Do you have a smart charger for your battery? Must check bike charging system with a known good, fully charge battery, as depleted batteries will dominate all voltage readings.

StreetSpirit · « **Reply #9 on:** June 06, 2012, 02:28:37 PM »

So in other words I need to be running it above about 4000rpms in order to support lights... That's pretty well impossible around here.

bollingball · « **Reply #10 on:** June 06, 2012, 02:36:23 PM »

The best thing to do is keep it on a smart maintainer when not in use.
Ken

TwoTired · « **Reply #11 on:** June 06, 2012, 03:26:15 PM »

Quote from: StreetSpirit on June 06, 2012, 02:28:37 PM

So in other words I need to be running it above about 4000rpms in order to support lights... That's pretty well impossible around here.

No. The output power curve of the alternator rises steeply at about 2000-2500 RPM.
But, now you know why the stock bike had a much bigger battery than you have now.

You can't (shouldn't) use a battery maintainer intended for a lead acid battery on a LiFePo4 battery. It needs either a smart charger for that technology or constant attendance of a person knowledgeable about it's charging characteristics. Imo, you really need a voltmeter on the old SOHC4 if you have a LiFePo4 battery installed, as it needs charge parameters (monitoring) the standard Vreg knows nothing about, and therefore requires operator attention to keep it at proper potential.

You may still have issues with your current charging system that can make things worse than normal. But, we have no test data yet to determine if it is healthy, sick, or just abused.

We just pointed out the obvious, so far.

strynboen · « **Reply #12 on:** June 07, 2012, 07:16:08 AM »

have this on my 550..vhen i have learned to hold light/load in balance..i take it off the bike

Duanob · « **Reply #13 on:** June 07, 2012, 12:47:01 PM »

Quote from: strynboen on June 07, 2012, 07:16:08 AM

have this on my 550..vhen i have learned to hold light/load in balance..i take it off the bike

I have one too and I love it! it's the best gauge on the bike.

http://www.argusanalyzers.com/battery-monitors/products/bb-sbm12ps-battery-bug-battery-monitor-argus-analyzers.html

dave500 · « **Reply #14 on:** June 07, 2012, 12:55:31 PM »

these are a three phase unit,its not like some other bikes that have the separate lighting coil,clean all your connectors and if you have a multi meter check the stator and field coils,ive never had any trouble with charging on any 500/550 once their sorted.

luap · « **Reply #15 on:** June 07, 2012, 01:05:35 PM »

How is the voltmeter wired up on those bikes? Is it just one lead to battery positive an other to ground? Also is there a specific one you guys like running?
thanks paul

strynboen · « **Reply #16 on:** June 08, 2012, 07:13:10 AM »

you have to take the power aut on main key..
.volts meters eats power vhen they are on..
.so they drain the batteri if you put them direkt on battery

Duanob · « **Reply #17 on:** June 08, 2012, 08:03:02 AM »

Quote from: luap on June 07, 2012, 01:05:35 PM

How is the voltmeter wired up on those bikes? Is it just one lead to battery positive an other to ground? Also is there a specific one you guys like running?
thanks paul

I like the one I bought. I'm sure they all work similarly. I didn't hook mine to the battery because it makes removing the battery easier. I went to the other end of the battery cables for attachment.

dougan · « **Reply #18 on:** June 08, 2012, 12:22:07 PM »

I had the problem you describe when I bought my bike, a 350f. Probably basically the same thing. It'd drain flat with the headlight on, but run forever with it off.

It ended up being the connections to the rectifier. There are 3 yellow wires and 2 others, maybe a red and black (diagram on this thread shows it as red and green, that may be the case). Anyway, assuming your bike is the same as mine, the shop manual gives instructions on how to test that your rectifier works using an ohmeter. I took mine apart, noted that the connections weren't the stock connections and weren't great. I did the ohmeter tests and found that my rectifier works fine. When I reattached it, I got new connections and used dielectric grease, and it's worked great ever since.

What voltage do you get at your battery terminals when you are at about 3k rpm? I would think at that level you should be almost up to 13.8.

StreetSpirit · « **Reply #19 on:** September 17, 2012, 12:21:12 PM »

Ok, so I went ahead and did some diagnostics and discovered a shorted stator! Ebay unit installed and just for good measure an upgraded battery (ballistic lifepo4 8 cell) and redid a large portion of the wiring harness. The bike runs great, nice bright lights, no problem charging or staying running.

I was afraid that it was going to be an expensive fix, but at least it's fixed.

Duke McDukiedook · « **Reply #20 on:** September 17, 2012, 12:29:17 PM »

Is a lifepo a lithium Ion Battery?

mronegear · « **Reply #21 on:** September 17, 2012, 01:27:59 PM »

cool, you have found the bug!

I had a similar problem with my 76 550f. In my case it was a corroded main fuse holder which caused 0,6 Ohm and made the bike not charge properly with headlights on.

cheers,
Frank

sir funk · « **Reply #22 on:** September 18, 2012, 06:57:10 AM »

Quote from: DukieFrankenkit on September 17, 2012, 12:29:17 PM

Is a lifepo a lithium Ion Battery?

Also called Lithium Iron Phosphate or LFP Batteries- Bit more stable than typical Lithium Ion batteries. Won't blow up/catch fire in an accident.

mono · « **Reply #23 on:** September 21, 2012, 09:13:52 AM »

Quote from: sir funk on September 18, 2012, 06:57:10 AM

Quote from: DukieFrankenkit on September 17, 2012, 12:29:17 PM
Is a lifepo a lithium Ion Battery?

Also called Lithium Iron Phosphate or LFP Batteries- Bit more stable than typical Lithium Ion batteries. Won't blow up/catch fire in an accident.

no explosions?! if you're already crashing, you may as well do it like Michael Bay...

crazypj · « **Reply #24 on:** September 21, 2012, 09:18:46 AM »

You should check bulb IS an H4-35/55w, most likely its a 60/55w
I use H4-35/35w from early Yamaha FZR1000 (also fitted to a lot of scooters, so I'm told)
K&L lists a 45/45w H4 but I haven't tried one

saxamaphone · « **Reply #25 on:** September 21, 2012, 09:49:37 AM »

I found a cool charging mod for my CB450K6 here http://www.hondatwins.net/forum/viewtopic.php?f=53&t=6185.

Not sure if anything like that exists for the fours.

TwoTired · « **Reply #26 on:** September 21, 2012, 10:06:24 AM »

Quote from: saxamaphone on September 21, 2012, 09:49:37 AM

I found a cool charging mod for my CB450K6 here http://www.hondatwins.net/forum/viewtopic.php?f=53&t=6185.

Not sure if anything like that exists for the fours.

It doesn't.

saxamaphone · « **Reply #27 on:** September 21, 2012, 10:16:43 AM »

That's good to know. Even more impetus to make sure you have your charging system working as good as possible.

strynboen · « **Reply #28 on:** September 21, 2012, 12:31:06 PM »

only work on simpel 1/2/3 fase generator...can be done on yamaha fs1 and honda cd 50. and other moped liked small mc.if they are used in city traffic..but the battery have to be kontroled often..you boil the battery vhen driving NO. light on

stockscreamer · « **Reply #29 on:** September 21, 2012, 01:06:34 PM »

I know your problems already been solved but i had issues with charging due to a dented dynamo cover which in turn had the field coil tweaked inside causing contact to the rotor. did every single electrical test known to man for these bikes and came up with a defective field coil a couple times and a couple other times it tested good.. measured the difference in depths with a straight edge across the gasket surface and shimmed it straight, adjusted the regulator gap and taa-daa good as new-ish ; )

Long story short if your dynamos scratched/dented check the gizzards.

Josh

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Author Topic: Headlight drains battery (Read 9635 times)

bollingball

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