Testing for a Battery not Charging

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Thanks to Flyinfool for this great tech article.

 

Testing for a Battery not Charging.

 

1. Start by fully charging the battery.

A.

Charge at a low rate of about 2 Amps for at least 12 hours.

B.

A faster charge will put in a quick surface charge not the deep charge that is needed.

2. Clean all of the charging circuit connections.

A.

This includes, positive and negative battery terminals, the frame and engine grounds, starter motor connection, solenoid connections, Regulator / Rectifier (RR) connector, Main fuse connections, and Stator connector.

3. With the bike running at over 2,000 RPM check the voltage across the battery terminals. See note below.

A.

The voltage should be between 13.5 and 14.5 volts DC.

B.

If the voltage is less than 13.5 go to step 4.

C.

If the voltage is more than 14.5 replace the RR and start step 3 over.

4. Test the battery

A.

With the battery fully charged have it load tested.

a.

Many stores that sell batteries will do this for free.

B.

If battery is good reinstall and go to step 5

C.

If battery is bad, replace and go back to step 3

5. Test the rectifier diodes, (Unfortunately there is no easy test for the regulator)

A.

Disconnect all wires from the RR.

B.

Set your ohm meter to either diode test (preferred) or its scale closest to 2K ohms.

C.

Connect the black meter lead to the black wire of the RR.

D.

Test each of the 3 white wires with the red lead of the meter.

a.

They should each show continuity (low resistance)

E.

Connect the red meter lead to the black wire of the RR.

F.

Test each of the 3 white leads with the black meter lead.

a.

They should each show no connection.

G.

Connect the black meter lead to the red wire of the RR.

H.

Test each of the 3 white wires with the red lead of the meter.

a.

They should each show no connection

I.

Connect the red meter lead to the red wire of the RR.

J.

Test each of the 3 white leads with the black meter lead.

a.

They should each show continuity.

K.

If all of the tests in C. thru J. pass go to step 6

L.

If any of the test in C. thru J. fail replace RR

6. Test the stator. (All stator tests are with the stator unplugged from the RR.)

A.

Set ohm meter to its highest scale.

B.

Check from each of the 3 stator wires to ground.

a.

The reading should all be open.

b.

If the reading is a low number then the windings are shorted to ground. Stator is bad.

C.

Set ohm meter to its lowest scale.

D.

Check the resistance between each pair of white wires, ie 1-2, 2-3, 3-1.

a.

The readings should be 0.36 to 0.48 ohms at 68°F (20°C)

b.

The readings should all be very close to the same.

c.

Readings

outside of the range indicate a bad stator.

1.

This test is not always a 100% indicator of a bad stator since many less expensive meters are not sensitive enough to measure this small of a resistance accurately.

E.

WARNING

– The following test has dangerous voltage present on the 3 stator leads.

Do not touch them. You will get a shock.

a.

Do not let the stator leads touch each other or you will have a bad stator.

F.

Set your meter to a scale to read more than 100volts AC.

G.

Start the engine and hold at above 2,000 RPM.

H.

Measure the voltage of each pair of white wires., ie. 1-2, 2-3, 3-1.

a.

The voltage should be over 50 volts AC and could be over 100VAC. Depending on exact RPM

b.

Each of the 3 wire pairs should show close to the same voltage.

I.

If one or more pairs of wires show a low voltage and/or the resistance test from D. shows a difference, then the stator is bad.

NOTE

Run test 3 with as many things turned off as possible and again with as many things turned on as possible. If the voltage is low only with everything on, you might just have too much electrical stuff for the system to power. But it could still be a marginally performing stator and/or RR.

 

By Jeff Borowski August 15, 2013