Charging problem?

Hi all,
So the story goes like this:

I bought my first big bike - a 99 SV650s after I passed my test and love it. A week into having it, the battery went flat and was stranded at a friends house. I borrowed a charger, charged it. a week or 2 later, flat again.

I bought myself a new battery thinking that would be the end of it. Now it's important to note that I didn't charge the new battery before I put it in my bike - (didn't think I needed to, a quick search on here revealed I was wrong). 4 days later - leaving work - flat battery again.
(now it's worth noting during those 4 days I did only use the bike to go to and fro work, all in all about a 10 minute trip)

So I'm thinking - I have a problem with the charging system rather than just a duff battery. I borrowed a multimeter from a friend and broke more than a sweat removing the rear fairings. (Presumed a likely problem with the R/R - sometimes a little knowledge isn't always your friend!)

Here are my results.
Battery with bike off: 12.89
Battery with bike @ 2500rpm: 14.00
Battery with bike @ 5000rpm: 13.99

EDIT: just realised these readings are with the lights off and didn't think to get a reading with the lights on :/

According to the fault finder I am following - (http://www.electrosport.com/media/pd...ng-diagram.pdf)
I don't have a problem with my charging system and just to check and clean my connections.

This seems too simple and am worried that the battery is just going to go flat on me again. My good lady wife turned around and said - "maybe you had a duff battery, you replaced it, didn't charge it so it went flat, but now that you've charged it it might be fine?"

I tend not to listen to her but could it really be that simple?

Any help would be much appreciated.

[Sid Squid]

A weak charging system may well give you those results with the lights off - test again with lights on and see what you get, it's not unusual to find that a below par charging system will keep the battery sufficiently charged if the lights aren't used, but the extra load of the lights will show up its deficiencies.

It would be a good idea even now to fully charge the battery, as soon as you can.

Check the whole bike for any loose wires, wires touching the frame or near the frame, as it may be a case of once in a while said wire will get dislodged touch the frame and discharge the battery, I had the exact same symptoms you have and after replacing the battery and the RR I still had problems. Until I striped it and cleaned, tidied etc

Thanks guys, I will test again with the lights and post results

Hello again,
The results are in (this time with the lights)
@2500rpm = 12.12
@5000rpm = 12.10

I continued to follow the flow chart, did a number of tests, think I got them right (no idea really about electrical stuff). I got to the stage where you are diode testing the r/r. The flow chart says the R/R is at fault and thus needs replacing.

While I'm here, could someone explain the whole deal with the cbr r/r's? is it worth bothering with or should I seek to replace with an original SV one?

Thanks

[Sid Squid]

Those results suggest a regulator that doesn't do its job properly.

Seeing as you have a meter, do an alternator output check, like this:

Originally Posted by Me! Several times now

Identify the three alternator output wires at the regulator, call them A, B and C, rev the engine to 5000 rpm and check voltages between each pair; A+B, A+C and B+C, each pair should give approximately 70VAC, +/- a bit, but all three readings should be essentially the same.
If the results you get are substantially different, or if one reading differs from the others, check the stator resistances between each pair and between each wire and a clean bare metal engine case point. I can't remember the exact winding resistance figures but it's something like 0.5 ohms, again all three readings should be essentially similar, and between each wire and ground should be open, that is no connection at all, if you find the winding readings good but one or more goes to ground check the wiring between the rectifier and the stator very carefully.

If the alternator passes - and I suspect it will - replace the regulator. I still don't understand the obsession with a CBR regulator, not that there's anything wrong with them, but they're nothing special, try to find a late model Yamaha or Kawasaki MOSFET regulator, far better voltage control.

I second that Re the CBR R/R. I got a mosfet ZX6R R/R for half the price of a CBR one. It even manages to fit in the original place albeit with one bolt. Never had a problem in the 2 years it's been on.

[yorkie_chris]

Originally Posted by Sid Squid

If the alternator passes - and I suspect it will - replace the regulator. I still don't understand the obsession with a CBR regulator, not that there's anything wrong with them, but they're nothing special, try to find a late model Yamaha or Kawasaki MOSFET regulator, far better voltage control.

The late CBRRRR ones are MOSFET too

[Sid Squid]

True - almost never the ones used though. The whole 'you need a CBR one' is rarely used with any deep understanding of the details.