Battery/Alternator Problem very confusing

Hi Guys,

I've recently started riding a curvy (T reg - 1999) SV 650SX, and am loving it! The previous owner had made a few modifications to the bike, these being:

- After market rear and front indicators.
- Wolf exhaust can.
- Cosmetic mods (belly pan, dark windscreen etc.)

The problem I am finding is that sometimes my bike will not start, and at the time it is obviously due to a low battery - tries to start, starter motor turns, lights and dashboard lights go dim and then out.

I bought a battery charger and maintainer, and it seems like the battery is good, it is in very good condition (no corrosion) and once fully charged it held its charge for 2 weeks outside of the bike. It takes a normal time to charge, so i assume it is ok.

I then left the fully charged battery in the bike for 2 weeks, and today had a good ride - 30 miles out and 30 miles back (about 2 hours riding in all.) It started fine before my ride from cold, and started fine for the journey home (after being left for an hour.)

But 5 miles from home i pulled in to re-fuel, and it was after this that the bike wouldnt start. I managed to bump start it and get it home, and on getting home i turned the bike off, and immediately re-started it 3 or 4 times with no trouble at all.

Surely the 5 miles home wasnt enough to charge the battery to an adequate level for that many starts?

Im not sure if this is a battery, alternator or wiring problem (wondering if the aftermarket indicators could have been wired incorrectly) so any help will be greatly appeciated!

Thanks,

Jum

Get a volt meter on the battery terminals.

Take a reading with engine off, engine idling, and at 5,000 revs.

Had similar issues with mine. Turned out to be regulator/rectifier unit (do a search here). A common problem and not that expensive. Take voltmeter readings first though.

[Biker Biggles]

Originally Posted by Southgate

Get a volt meter on the battery terminals.

Take a reading with engine off, engine idling, and at 5,000 revs.

Had similar issues with mine. Turned out to be regulator/rectifier unit (do a search here). A common problem and not that expensive. Take voltmeter readings first though.

Yes.And check all the relevant connections-----Battery terminals and the earth straps to frame and engine.Then check the wire that goes to the starter motor.

its weird that it wouldnt start then would after 5 miles no way near enough time to charge it properly, i had a similar issue with mine when i first got it an i found a loose connecter under the front seat that was low voltage feed to starter solanoid i think it was, like above check your charging voltages idle,at 5k, at idle with lights, at 5k with lights.
Ben

[keith_d]

Stuff to check first:

1) Remove both battery connections, clean off any corrosion, cover in vaseline and re-connect
2) Remove, clean and reconnect the earth connection to the bike
3) Inspect the earthing block where all the black wires come together from the instruments etc. checking for corrosion.
4) Check the connection between the starter solenoid and the battery (thick red wire)

After checking the connections

1) Charge the battery using a charger
2) Check the voltage. Leave it overnight then check the voltage again. If it's below 12V you've probably got a dead cell and will need a new battery.
3) Connect the battery to the bike
4) Turn the lights on and check the voltage. If it drops below 12V you're battery is sick and should be replaced.
5) Start the bike
6) Measure the voltage while idling. It should be above 12.5 volts.
7) Increase the revs to 5000 and check that the voltage is around 13.5 volts

Failing checks 6 and 7 indicates a problem with the charging circuit on the bike. Check the connections on the Reg/Rec and measure the AC voltage on each phase of the generator. (I can't remember what these should be so you'll need to check the manual.) If the generator output is OK but the charging voltage is still low you probably need to replace the reg/rec.

Hopefully one of the real mechanics will come along and point out anything I've missed.

Keith.

Thanks for the replies guys!

I think the first thing i need to do is get a multimeter on order, meanwhile i will check the wiring suggested.

Does anybody have any recommendations on a good multimeter to buy? Ive had a look at some Fluke ones but they seem a little out of my price range.

I'm willing to spend up to £100, any suggestions?

Cheers

[andrewsmith]

RS Components or Maplins.

My previous place used to get cheapish ones due to the cost of Calibrating them yearly and had no issues.

Cheers for the recommendation! I got a decent one from Maplins for a good price!

Finished testing now, wires all seem to be in good condition. Left the battery full charged since starting this thread and it still reads 12.9V.

Idling with the lights on i only read 12.4V, at 5000rpm still only 12.4V.

Unregulated voltage before the regulator read about 85-90VAC on average between all 3 phases.

Pretty sure this is pointing, with a huge arrow, towards the regulator/rectifier!!

Cheers for your guidance guys! Now where would be the best place to get a replacement reg/rec?

Thanks again!

Consider upgrading to a mosfet type. Do a forum search, loads of info.

[TSM]

Originally Posted by Jumbungla

Cheers for the recommendation! I got a decent one from Maplins for a good price!

Finished testing now, wires all seem to be in good condition. Left the battery full charged since starting this thread and it still reads 12.9V.

Idling with the lights on i only read 12.4V, at 5000rpm still only 12.4V.

Unregulated voltage before the regulator read about 85-90VAC on average between all 3 phases.

Pretty sure this is pointing, with a huge arrow, towards the regulator/rectifier!!

Cheers for your guidance guys! Now where would be the best place to get a replacement reg/rec?

Thanks again!

check all your connections first, corrosion etc..

dont faf with second hand if you expect to hold onto the bike
http://www.electrexworld.co.uk/rr85-...er-3206-0.html

someone said 5miles is not enough to keep bike charged, well i can say that is is as for ages i did a couple of miles to and from work and bike was fine