Electrical question

[Jacko]

Hi,
'98 600 boxeye. Running standard single dip headlights. Indicators and brake lights dim headlights.
Meter across battery shows 13v. Engine running it's up to almost 14v. When lights on voltage drops and with brake light it's down to just 12v so not charging much if at all.

Will this be as simple as crappy connections or is there something else to check.

[Grayo]

Could be crappy connections but sounds more like a bad earth to me. I would also change the battery while I was at it just for peace of mind.

[darrsi]

It's because the bike is only ticking over, once you start riding the charging volts will rise.
Fairly similar results to what i found the other day before i changed my battery, so i've learned now to start the bike with everything else switched off to ease the burden, like headlights, heated grips,etc.

[darrsi]

.

[Jacko]

Hi, these results are at a steady 5000 revs. With lights on voltage drops to 12. Bike used every day for work.  Battery takes charge OK and charger shows all good. Not going flat as a run without lights and it's fully charged again. Dark winter commute gonna kill it though.

[darrsi]

Probably just a shagged battery then, i had similar problems a while back with having a flat battery every few weeks, had to keep getting a jump start, and i thought it was loose connections, not charging, etc.
Most likely a dodgy cell in the battery so it's just not man enough for the job, and you're right, it will die a death in winter.
Bought a new one and has started first time without issue ever since i've had it, but as i said before, after learning how much power the lights drain the battery i've got into the habit of switching them off when the bike cranks over to take away that added effort. 


If you do order a battery be careful that you check the physical measurements, as i found that the codes can very slightly differ resulting in a different size battery, and there's not much room to play with.
I chose this one because it was 12ah, whereas a lot were only 10ah.


http://www.ebay.co.uk/itm/VARTA-YT12B-BS-12v-12Ah-AGM-Motorcycle-Battery-/311057282347?_trksid=p2141725.m3641.l6368

[Jules-C]

At 5,000rpm the alternator should be putting out enough to power the lights and charge the battery even if the battery is having problems. It could be faulty rectifier/regulator

[darrsi]

Just found this, gotta be worth a go at that price for a brand new part.


http://www.ebay.co.uk/itm/Regulator-Rectifier-Voltage-Fit-YYAMAHA-TDM850-XVZ1300-95-05-FZS600-98-03-2002-/131919012179?hash=item1eb6fc6153:g:kZwAAOSw-itXvqzK