Charging/battery problems

Hi peeps

I'm new to the motorbiking world and bought myself a '99 SV650S yesterday, great bike, love it (from what little I've ridden it so far!).

I'm having problems with the battery, after buying it I rode from Reading back to Bournemouth (~80miles), started fine, however half way back after a petrol stop it refused to start. Engine was turning over, albeit sluggishly and slowly - dead battery.

I've searched quite a few threads on here, found some very useful info on this. I plan to take voltages whilst engine off, running (2k) & (5k) with lights on/off etc as other posts suggest. (Charging voltage @ 5k is ~12.9v) Will post full results later.

However, I took the battery out today and found it was a Yacht battery?! Could this be a possible cause to my problem. I would guess that a yacht battery would be similar to a leisure battery, ie designed for continuous low ampage use and not suitable for the high current draws which are required to turn an engine over. Did the seller throw any battery he could find in it just to sell it? See pic below.



Thanks in advance for your comments.

Graeme

[Biker Biggles]

Looks like you are checking the right things.Post the results and hopefully it will just be a case of getting a decent battery rather than issues with the charging system.

[yorkie_chris]

Yacht are a company.

Your charging system appears to have a problem. Check for ACV at the alternators connection with the reg-rec ... should have at least 60VAC at 5k rpm there.

What Chris said...

Battery power is given in Volts and Ampere Hours, and as long as your replacement has the same voltage, and the same or greater AH than the original battery, you're fine. Make and models don't mater so much...although some will give longer service than others.



Voltage at the battery should be around 14.5 volts at a few thousand RPM, in order to charge the battery.

Thanks for your input guys.

After leaving my battery connected to Opimate for 24hours I checked various voltages:

Battery voltage (all off): 13.4vDC
Lights on (engine off): 11.7vDC

2k lights on: 13.7vDC
2k lights off: 18.2vDC
5k lights on: 14.0vDC
5k lights off: 18.8vDC

I also checked the phases on the rectifier:
2k: 47vAC, 31vAC, 39vAC (3 phases)
4k: 55vAC, 69vAC, 41vAC (3 phases)

(These were all taken from a coldish engine, it was in my garage with the door open but even so didn't want to leave it running too long)

These differ slightly from what I remember the AA man checking the other day, it was about 12.9v @ 5k and about 12.5v with the lights on @ 5k. Much, much lower charging voltages? (the engine would of been at operating temp)

[yorkie_chris]

It would appear the regulator is stuffed.

[Biker Biggles]

Showing 18+ volts at any time is bad news.The reg isnt doing its job and will be cooking the battery.New reg required,and you may have to get a battery as well.

Thanks for the quick replies. Does this explain why I had a flat battery on the way home though?

Does anyone know of a cheap place to get a new rectifier please? I presume they're all the same of the SV's from '99 to '08?

[Biker Biggles]

Honda CBR 600RR ones are a popular substitute,but you need to splice some wires(there are too many).They fit well though and seem to be reliable.Often on Ebay fairly cheap.I put one in my curvy over a year ago and it has been fine.
If the battery is overcharging it will overheat and fail even while you are riding.