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Online Art

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #20 on: 16 October, 2020, 07:56:42 AM »
*Originally Posted by BigGinger [+]
Am I looking for 13.2v because thatís what I got last time? Iíd be a lot more comfortable with 14v or so. Iím not riding around at 3-5k revs constantly, just because Iím paranoid Iíll end with a dead battery if I donít.

Because a 12v battery is made up of 6 x 2.2v cells therefore at 13.2v the battery is neither charging nor discharging.

You don't really want to see a 15v output from the regulator/rectifier which is borderline cook the battery territory. Around 14.2v is where you want to be from about 2,500 RPM

Online Art

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #21 on: 16 October, 2020, 08:24:07 AM »
Did you check the charging system wiring loom?

As posted previously select the 20v DC range on the multimeter and with the engine idling at 1,200 RPMÖ

Connect the black DMM probe to the battery positive terminal and the red DMM probe to the red output cable of the regulator/rectifier. Expect less than 0.2v. If greater than 0.2v disconnect, clean and check all terminals, connections and fuses in the positive cable from the RR to the battery.

Connect the red DMM probe to the battery negative terminal and the black DMM probe to the green output cable of the regulator/rectifier. Expect less than 0.2v. If greater than 0.2v disconnect, clean and check all terminals, connections and chassis ground points in the negative cable from the RR to the battery. Alternatively you could run a ground cable from the RR (green cable) direct to the battery negative terminal.

Fix any faults and re-test the charging system output again.

If it helps to put your mind at rest the last time I tested my charging system I got the following results which are typical for the CBF1000

Battery initial level of charge 12.5v
Ignition on, headlamp on for 2 minutes voltage drops to 11.8v
Cold cranking 5 seconds on full throttle (disables fuel system) voltage drops to 10.7v
Load test idling at 1,200 RPM headlamp, hazards and fan on voltage drops to 11.8v
Load test at 2,500 RPM headlamp, hazards and fan on battery voltage rises to 13.4v
Charging System output, no battery loading, test at 2,500 RPM battery voltage rises to 14.2v
Charging System output, no battery loading, test at 5,000 RPM battery voltage remains at 14.2v



Offline angelin

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #22 on: 16 October, 2020, 09:47:46 AM »

hello yes to reason regarding the battery that should make up for the generator but if the current is more that which comes out than that which is produced with all the loads on. on my mk2 I did 100000 km with original alternator. I have not installed accessories that could jeopardize the recharge. because the more charged the more the generator becomes overheated

Online Art

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #23 on: 16 October, 2020, 11:28:47 AM »
*Originally Posted by angelin [+]
hello yes to reason regarding the battery that should make up for the generator but if the current is more that which comes out than that which is produced with all the loads on. on my mk2 I did 100000 km with original alternator. I have not installed accessories that could jeopardize the recharge. because the more charged the more the generator becomes overheated

Again not quite how the Charging System works. The stator (generator) works constantly producing up to 40v AC output across its three phases depending on engine RPM. The regulator/rectifier then converts that output to vDC and caps it off at around 14.2v DC which it then feeds to the battery according to battery loading with any surplus output being shunted to ground.

Offline angelin

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #24 on: 16 October, 2020, 12:13:40 PM »

340w: 13 volts nominal = 26 amps. if you disconnect one fuse at a time you see the load of each user you add them and you see the load that the more accessories you insert more generator tries to supply current but automatically the voltage will drop. the battery cannot withstand a higher load because its capacity accumulating current is only 8 amps.

Offline BigGinger

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #25 on: 16 October, 2020, 02:16:09 PM »
Iím an entire volt down, 13.2, which Iím only really getting at 4-5000 revs. Iíll be testing things tomorrow and Sunday, Iíll report back with those findings once Iíve followed your instructions. Thanks guys