Dead battery

[Nogshere]

Hi Guys, Looking for a bit of help with a battery issue.
A few months ago, I got ready for ride out but the bike wouldn't start, checked the battery and it was flat. As the bike was 4 years old I thought I'd just get a new battery and all would be ok. I also bought a small solar charger and plugged that in. I've been using the bike fairly regularly so no problems since - until yesterday when I went to start it after 3 weeks of no use due to holiday and nothing happened!! I checked the voltage and it was 4.4 v? I've looked in other posts but there doesn't seem to be a common problem so would appreciate any ideas as to why this is happening and any possible solutions.

Best regards
Ian

[mzflorida]

A circuit is leaking: Test by removing the negative cable and placing your volt ohm meter between the terminal and the battery.  Anything larger than a few milliamps means something is drawing and draining. .5 amp is too much.    This one is the worst and most difficult to diagnose...also the most common. 

Rectifier:  Under your seat, has six terminals I believe.  Cannot miss it; it is just to the right of the battery as you are looking down from the left side of the bike  These go bad and will drain your battery.  The manual has the specs for testing.

Ground wire:  Clean them all with fine sandpaper.

Voltage too low to power all accessories while riding:  Check voltage to make sure you're at 13.5 or higher at 2500 3500 rpm.

[Nogshere]

Thanks for the reply, will have a look over the weekend and let you know my findings.

[mzflorida]

Made two errors in my post.  The rectifier is on the left side of the battery tray as you are looking down from the left side.  I meant to say place your volt ohm meter between the negative cable and the negative terminal. 

[Showkey]

The common cause of battery going dead while sitting:

Accessories connected directly to the battery like:

Heated grips
GPS
Cell phone chargers
USB chargers and outlets
Alarm systems


Normal  parasitic draw on the CT is 10ma or .010 amps.   

[mzflorida]

Originally Posted by Showkey

The common cause of battery going dead while sitting:

Accessories connected directly to the battery like:

Heated grips
GPS
Cell phone chargers
USB chargers and outlets
Alarm systems


Normal  parasitic draw on the CT is 10ma or .010 amps.   

Agreed on all and makes the case for a FuzeBlock or similar with a relay. 

[Nogshere]

So did a few checks over the weekend, results so far.

Put the battery on charge overnight and it was reading 12.7 in the morning. Then disconnected the charger and left it standing a while and it was reading 12.4 by late afternoon, not sure if this is significant?

Also connecting the multimeter between the negative terminal and the cable shows 0.67mA so I take it there isn't a leak in the electrical system?

Checked it again the next day and everything is still fine, started the bike up and the voltage when idling was 14.24 but this dropped slightly to 13.94 at 3000rpm, again not sure if this is significant?

Anyway I bought a battery optimiser and connected that up yesterday and this morning the battery is reading 13.42V, so I think I'm going to turn that off now and just leave the bike standing for a few days and monitor the voltage

Bit confused about the location of the rectifier, as when stood on the left side of bike I can't see anything to the left of the battery, but there are a couple of items to the right but I don't think these are the rectifier, I've tried to insert a pic but I don't think it has worked!!.


Thanks for the help so far
Regards
Ian

[mzflorida]

A .067 parasitic draw translates into a loss of about 1.7 amp reserve loss every 24 hours (.067 x 24).  That presumes a well-maintained or a brand new battery in perfect conditions.  Warmer or colder climates can compound the rate of loss.  I do not know the reserve amps on the Yuasa battery. Your voltage under load seems fine. 

The new chargers, like the optimate or other computer-controlled chargers, desulfate your battery, which could have been the issue.  They actually dissolve the sulfate and improve the performance of the battery.

To view or test the rectifier, you may have to remove the battery.  Picture where the seat meets the tank and it sits right about there.  I looked at the manual; pages 22.7 show how to test the rectifier.  If there is not a copy here I can share a version of the 2016 manual that I have if you PM me your email address.  I can share it via google drive.