Help with Dry then drained battery

[Slimbob]

All,
Mostly Stock 77 650-D

My bike hase been running great since I put the Pamco Electtronic ignition on her. I checked the water in the battery at beginning of the riding season. About 2 months ago.

Last Thursday I was on my way to work and noticed the horn was very weak. And my reserve lighting warning light was on. But still able to switch between low and high beams.

I checked the the battery voltage and was down to 11.5 off, 12.5 idling, and 13+ >2K RPM. Water Level was down below the tops of the plates in several cells. Filled with bottled drinking water. No Distilled available. Kick started @ 5PM and drove home. Figured the 22 mi ride would charge the battery.

Didn't try to ride until Saturday night. Battery was bone dead.

Pulled battery and put on Smart trickle charger for 2 days. Put the battery back in and all was well on a 10 mi ride. One thing I noticed was there was a relay that would click when I re-attached the battery as I touched the - cable to the post. Think it was the Reserve Lighting module.

That was last night. Figured the RL module was probably bad and the battery would be dead in the morning. NO!

Rode to work this morning and bike was running good. All is good.

Do these RL relay modules go intermittent? There should not be any voltage feeding the RL module with the key off. Is it possible for this module to drain the battery? Can't think of anything else that might have caused this. Ignition switch maybe not breaking the connection fully?

Any ideas? Don't want to get left on the side of the road. I should probably replace the RL module at least, since the waring light is on most of the time. Are Mike's replacement modules ok or should I source elsewhere?

Any other ideas what could be cooking the battery and then not charge it and drain it in 2 days?

Thanks in advance,
Slimbob

[preston]

I have no ideas about the RL relay module.
But it sounds like your regulator, is allowing over charging to dry up the battery.
I hooked up a multi-meter to my battery, and zip tied that to my handle-bars.. ( no funds to buy a little one ) to see in real time, what is going on. (voltage wise)
We have adjustable regulars, two sets of points to service and adjust,,, and you need to find those threads and read on that subject what 5 Twins and others wrote about. ( to reduce your output, IF that is the case)
Preston

[Slimbob]

Hey Preston,
I got your pics of the meter. Great idea. It sucks that now I have a problem after rebuilding the front forks and putting the Pamco electronic ignition. She was running great. Think I need to re-sync the carbs and should be good for the summer after I figure out the electrical issue.

Thanks again,
Slimbob

[Slimbob]

The battery seems to be holding a charge ok so far. The RL module still has the waring light on most of the time. I think I'm going to replace it now.

I guess Mike's XS is a good source for this. Any preferences?

I haven't had a chance to dig into it yet but rode the bike last night for the first time since Friday and it seemd to hold a charge ok.

Want to try the Volt meter while running idea.

Thanks,
Slimbob

[xsleo]

Getting a volt gauge and mounting it some where on the bike is a ggod idea. This lets you keep track of the charging system all the time.
I got one a Harbor Freight for around $5. Made a mount to mount it on the handlebar risers.
Leo

[Slimbob]

Bike ran ok for several days. No issues. After leaving sit for a week, the battery is dead again.

Heard the relay pull again when I attached the second battery cable (key was off). Ordering a new Reserve Ligting module today.

Can I disconnect the reserve lighting module without affecting the operation of the bike? Something is draining the battery when it is sitting.

Don't know why power would be getting to the module when the key is off.

Thanks,
Slimbob

[preston]

SB:
I still have had no issues, or problems with RL relay. Don't know where it is or what it looks like.
and for that, I am very thankful.
You can do a "load test" on your fully charged battery and see if it fails ( most shops can do that for free, i would think )
Rule that out, just in case a bad battery.
Some are bad, right out of the box.
(and check those battery connections, grounds and things)
Be sure you are charging 13.5 to 14. 3 range..
( on my 75 and 77 rides, In the regulator, i have cleaned up my points, adjusted points to spec, and then then with final adjuster screw, dialed in Volts (all checks, were done at highway speed, with an attached muti-meter) and I am very satisfied with output now.
I put new brushes this past winter , and that changed nothing, it was the regulator that out of adjustment.
I still would like Hugh's PMA, and I am saving up for that system.
Best to you
Preston
PS, most 650's do not like to sit 7 days without riding, so they get back at you, like when you do not pet the dog.

[Slimbob]

That's a good one Preston.

I now have a digital multimeter that I can mount on the bike and monitor the system. It also has a Amp meter so I can look at current draw with key on and off. Will check it out this W.E.

Thanks guys,
Slimbob

[Slimbob]

OK! A bit more info. Did not get to ride this W.E for weather. But... While monitoring the battery voltage:
Off=11.79 VDC
Idle=12.8 VDC
2000Rpm= 13.5 VDC
At around 3000 Rpm the voltage drops from 14.0x to 13.5 VDC
Never goes above 14.0x VDC

Does this sound like a regulator/rectifier?

I did not try to monitor current draw yet.
I gues this thread should be moved to the charging area.

Slimbob

[preston]

As far as I know,
A good battery, with engine turned off, battery just sitting there connected up,,, should be 12.4 to 12. 7 volts.
( at least my two are like this, and they are 2 and 4 years old)
Your battery sounds low to me.
Idle 12.8 is normal ( lights and coil draw current)
My black 75 bike , will drop volts slightly after 3,700 rpm , the blue 77 seems to hold its own . (volts dropping may be normal for a 37 year brush charging system at higher RPM ?)
Adjust the regulator per specs ( it is on left side, under cover, take off bike carefully, do NOT mess up wire conections)
Once you have the regulator points cleaned, and set within range...
after checking your output ...
IF NEEDED
then deal with turning the little ajuster screw, in. That will increase you charging output.
Turn it in about 1/4 turn , then ride for couple of miles, with 1/2 your eye, on the voltage of battery. ( taped on the bars, multi meter)
Turn this litlle regualtor screw in ,(1/4 turn at a time) until you have 14. or 14.2 with lights on at 3,500rpm and forget it.
(until something else goes haywire )
IF that does not work, call Hughs Hand Built, and speak to him about the newer regulators, and rectifiers, or look at the threads here, about Radio Shack components to make your own,,,,
with Chrysler car parts, and etc.
Preston

[madmax]

Bob

All the info on refurbing & tweaking your mechanical regulator is here xs650temp.proboards.com/index.cgi?board=Charging&action=display&thread=17121&page=1

Sounds to me like your battery is knackered though if the voltage is dropping off after standing a few days.

Max

[xsleo]

A bad rectifier can allow voltage to leak to ground. Draining the battery. Fully chasrge the batery, unplug the rrectifier, Does the battery go dead? If not then your rectifier may be bad. The test procedure and specs are in your repair manual.
Leo