Battery voltages

[Chris_SVS]

So having some cold start issues lately and not knowing a lot about the battery history of my K6, I changed it for a nice new one this morning.****

(no load) 13.8v
(ignition+lights) 12.8v
(Engine) 16.4v

Compared to the new battery

(no load) 14.8v
(ignition+lights) 14.2v
(Engine) 17.3v

Could I reasonably assume there is a charging or R/R issue at play here?

****I have a Bibio gizmo installed but none of the accessories were turned on or plugged in (heated grips/garmin cradle/12v socket)

[andy650]

The engine running voltages are way too high. No wonder the old battery died.

Suspect RR, but also check the wiring which is particularly prone to being weak.

[Chris_SVS]

Silly question, which wiring?

[Bibio]

yup those volts are a tad too high. sounds like the RR is failing which is not common on a K6.

to get at the connectors for the RR requires you to take the airbox off then on the right hand side of the bike at the side of the front cylinder there is the RR bolted to the fame. take the connectors off that exit from the RR and have a good look at the condition. these connectors are 'waterproof' and can fill with moisture so if there is then dry out and apply some ACF50.

next up is to try the output voltages from the generator (remember to switch the DMM to AC)







if that does not fix it then i would presume that you need a new RR or generator.

[Bibio]

forgot to say the easy way to keep the engine running at 5000rpm is to put an elastic band on the throttle and the brake lever then move the band.

[Chris_SVS]

Regulated voltage at idle (I took my readings on startup during fast idle around 3k) Both old and new battery 16.4 and 17.3 respectively

All of the coil resistance readings were 0.5 - 0.6 ohms

Generator test not done as it's sunday and my neighbours hate me already.

R/R testing itself, done with reversed polarity. My borrowed tester displays a 1 for a reversed diode

BR BR BW BW
B1 647 647 1 1
B2 645 645 1 1
B3 646 646 1 1

BR BR BW BW
B1 1 1 606 607
B2 1 1 606 605
B3 1 1 611 611

The only thing that looks wrong here is the battery voltage at idle, which suggests regulator?

[Bibio]

its a while since i have tested an RR.

fresh battery should be around 13v with ignition off
with ignition on it will drop to around 12.?v
at idle it should be around 13.?v
at 5k revs it should be around14-15v

if any of those voltages are higher than should be then its more than likely the RR.

now here is the sticky point. the more AC the generator kicks out the more DC the rectifiers in the RR will pass, usually this is not much of a problem with a few odd AC voltages here or there as the regulator takes care of it. if the generator is kicking out a lot more AC then the regulators cant cope and overheat then fail.

if the rectifiers fail then it will pass AC voltage or no voltage so since you are getting DC voltage then that part of the circuit should be fine.

so you have to test the AC voltages to determine if it is the generator or RR. thing is if it is the generator then most of the time its taken the RR out as well.

if the AC voltages from the generator are fine then its the RR but without testing the AC you will never know.

99% of the time its the RR that fails.

[Bibio]

another side thought.. when was the last time you checked your oil level?

[Chris_SVS]

Gotcha, will get it sorted tomorrow without being as anti-social

Thanks for your assistance, much appreciated

[Chris_SVS]

Originally Posted by Bibio

another side thought.. when was the last time you checked your oil level?

Couple of weeks ago, I actually noted today on my whiteboard to change it in about 1000mi, no filter due this time