Battery not charging with lights on

[Trylski]

Honda CBR600f '99

The battery doesn't charge when being ridden, so I have to keep charging it with a mains charger every couple of days.

The charged battery voltage is 12.7v, fine according to the Haynes manual.

Followed the test for current leakage, which seems to be zero.

When doing the output test @5000rpm I got two readings:

Lights OFF = 14.85v
Lights ON = 12.8v

The range in the manual says 14.7 to 15.5v. I've tested the regulator as described in the manual and it's fine, I wanted to ask if there's any chance that there is a fault with the lights that causes them to draw more power than they should.

Otherwise I'm fairly certain I need to pull out the alternator which is gonna be a pain.

So, what do?
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Current Bike: Suzuki Bandit N600 '99,
- CBT: Passed 02/2008 - Theory : Passed 24/02/09 Test: Passed 09/03/09 - 2011 33bhp over

[martyn107]

Guessing all the wiring looks ok?

[Trylski]

I've only given it a quick look over, will be having a proper look tomorrow. I didn't notice anything obviously damaged
____________________
Current Bike: Suzuki Bandit N600 '99,
- CBT: Passed 02/2008 - Theory : Passed 24/02/09 Test: Passed 09/03/09 - 2011 33bhp over

[Ed Case]

It's fairly normal that when the lights are on and the engine is being used that the power consumption and power generation are about quits. Obviously that depends on the battery being in good condition.

[Walloper]

Probably the generator insulation breaking down. Bad insulation will result in power leakage to ground and low output under load.

The volts mean less than amps in ths case.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[Trylski]

[martyn107]

[unitynotsocri...]

If its not charging , its not charging . so check your electrical extras if used , like gps ,heated grips ,dayriding lamps etc
then check your alternator and ' bridge rectifier ' with a multimeter.
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nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS

[Walloper]

[trevor saxe-coburg-gotha]

[jjdugen]

Standard issue Honda charging system.
It will be, (in order of likely hood:-
Regulator / rectifier with one phase fried.
Alternator stator with one phase fried.
Poor connections in the fuse box, especially the main fuse on the starter solenoid.
You will need to measure the output voltage of the three AC outputs from the alternator. If they all show about 50 - 70 volts AC at 2000 rpm, then it will be the reg/rec.
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The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[J.M.]

My guess wold be a short somewhere on the lighting circuit considering that it's charging properly with the lights off.

That said, 12.8v is usually sufficient to start and ride a bike if your battery isn't toast. Has your battery actually run flat by riding with the lights on or have you just noticed the voltage is down?
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2004 R1 & 2018 XSR900

[Trylski]

Did some searching on google last night, realised I'd only checked the wiring for the regulator () and that the regulator is probably to blame. I've ordered a new one just in case.

The battery was charged with a main chargers up to ~12.7. After being ridden a few times and trying to start her up, all that would happen is the neutral light would dim a little when I press the starter. Never bothered to check the battery voltage when it went flat.

Nothing but standard electrics and a datatool alarm
____________________
Current Bike: Suzuki Bandit N600 '99,
- CBT: Passed 02/2008 - Theory : Passed 24/02/09 Test: Passed 09/03/09 - 2011 33bhp over

[andym]

Forgive the ignorance here, did you say you've actually checked the voltage when the bike is running and it's fine?

Have you made sure all the wires that should be connected to the battery are?

Only reason I'm saying, my battery died the day after I got my bike, so borrowed a spare which wouldn't hold a charge, so bought a new one, charged it up and went for a ride 65 miles later I stopped the bike and it wouldn't start again (but would bump OK), when I got home I checked the battery (after checking the reg/rec etc) and found I hadn't connected one of the small wires to the earth terminal

On idle I get about 14.6v when I turn the lights on it drops to about 12.8v which to begin with I thought was a bit much, but since connecting the battery properly it's started fine every time

[Trylski]

Just fitted the new regulator and checked the output voltage @5000rpm. Now reads 14.65v lights off and 14.6v with lights on.

Hopefully that's it all sorted. Cheers very much for all the help!
____________________
Current Bike: Suzuki Bandit N600 '99,
- CBT: Passed 02/2008 - Theory : Passed 24/02/09 Test: Passed 09/03/09 - 2011 33bhp over