Battery charging probs-rough guide

[bindie]

after a lot of probs i've had decided to post this up to hopefully help anyone with similar probs

(copied from american web site,i have a copy in pdf if anyone wants me to e-mail it to them)

Bike Battery Charging Problems - Troubleshooting & Fixing

This procedure can help you find out why your bike battery does not charge correctly, and help you

to fix that. This assumes that your bike has a permanent magnet 3 phase generator, a standard thyristor

shunt type regulator rectifier (RR unit), and a 12Volt battery. You will need simple workshop

tools including a multimeter with clips or an AVO, bits of wire and crimp terminals, a headlamp bulb

and a soldering iron.

It’s best to start at the beginning of the chart and work through each step in turn until the problem is

found and fixed. It is not so unusual to have more than one problem on a bike charging system, and

your bike will work better if all the problems are fixed.

Please use a GOOD battery. The battery must be fully charged up first, using a bench charger. If not

available, maybe you can borrow a charged good battery from another bike.

Step 1 - Bike Leakage Current Test

Put the battery back on the bike, but connect only the +VE clamp to the battery, leaving the –VE stud

not connected. The battery voltage should measure 12V7 to 13V1 across the stud terminals on top

of the battery. Measure the LEAKAGE CURRENT of the bike, by setting the meter to DC AMPS,

connect one meter probe to battery -VE terminal, connect the other meter probe to the bike harness

-VE battery strap / clamp. The current should be no higher than about 50mA (Ignition OFF). Press

the brake lever just to check everything is connected okay - the brake light should light, the meter

should read about 1A750. Note: 50mA leakage will take a week to flatten a 9Ahour battery.

If the LEAKAGE CURRENT is less than 50mA,

the bike leakage current is okay,

please proceed to Step 2.

If LEAKAGE CURRENT exceeds 50mA, there is

a fault on the bikes wiring harness, maybe in the

alarm. Try pulling fuses to locate the problem.

Step 2 - Battery Charge-Holding Test

Connect the -VE strap / clamp to the -VE battery terminal, so the battery is fully connected to the

bike. The battery voltage should measure 12V7 to 13V1 measured across the stud terminals on top

of the battery (ignition switch OFF). Switch on the headlights (ignition ON, engine OFF). Battery stud

voltage should drop slowly, maybe down to about 12v4 over a period of 30 seconds. Switch off the

headlights and ignition soon.

If battery stud voltage remains above 12V4, then

the battery is okay, please proceed to Step 3.

If battery stud voltage drops below 12V4, the

battery is not good and should be replaced.

Step 3 - Functional Test of Whole Battery Charging System

Complete all connections between the Generator, Regulator Rectifier Unit, Battery - just as normal.

Set the meter to show DC VOLTS and connect the meter clips only to the stud terminals directly on

top of the battery. The battery voltage should measure between 12V7 to 13V1 with engine OFF.

Start up the engine and run at low idle speed. Meter should show battery charging voltage around

14V4 (limits are 13V6 to 14V9) at idle. Increasing engine speed should produce NO proportional increase

in battery voltage, but often will produce some small and meaningless variations in voltage.

Battery voltage should always remain between 13V6 and 14V9 while charging.

Switching the headlight on and off creates big changes in power draw on the generator and battery,

which usually results in a slight reduction of battery charging voltage. On older bikes it may be necessary

to increase engine speed slightly (maybe 2500RPM) so charging can keep up with the headlight

current.

Charge voltage between 13V6 and 14V9?

Everything is good, battery charges perfectly.

Please clean up & go have a beer.

Charge voltage >15V? RR is defective, needs to

be replaced.

Charge voltage <13V5? Please go to step 4.

[JimR]

what happens if you have a 6 volt system ?

and to be fair I would never diagnose a non charging problem in this method.

but each to their own