Working Around The Problem 101

Evening Bpayne and welcome to the Forum.

You didn't specify as to how LONG (period of time) your confirmed Fully Charged (and in perfect condition) battery takes to discharge. BUT if it's anything like our 'fleet' of vehicles here (car, trucks & bikes) were looking at 2/3/4 weeks of NON-operation under usually below Freezing conditions for the things to Internally discharge (NOT shorting out) enough to NOT be willing to start (under freezing, NOT in a heated garage conditions). THIS unless I have every single one of these things (which I don't) on a 'Float' Charger (read: NOT regular charger) every minute of time they're NOT actually being operated! ADD to that, I’ve since (OLD and newer) converted every bike now over to AGM or GEL type batteries, which seriously put out a lot more CCA’s then conventional (read: Crappy!) old school ACID batteries do!

BUT man I sure feel your pain otherwise: I’ve continued to fight with a 1991 Pontiac Sunbird 2.0L (my wife’s car) for the past 9 years now. It does about the same friggin' thing your Honda 550 does. My wife keeps saying get rid of it – she’s right of course. BUT despite everything I gotta’ admit even though I ain’t a car guy at all, I’ve come to love this crappy little car! What can I say…..???? Friggin’ idiot!!! It’s the first car I’ve ever come to know with no holes in the seats, dashboard isn’t cracked, actually HAS a half-way decent paint job left, etc.! ;-) And when I drive this little cage, dog gone it it’s fun, what can I say?! I suggest getting yourself a ‘Float Charger’ from Harbor Freight – at about $5 to $7 bucks at last posting, and adding to that a standard Two Conductor Trailer Connector (couple bucks) plus a Yuasa Quick Disconnect Battery Connector – hook up all this to your scoot whenever your NOT riding it and boom – NO more dead battery problems! ;-)

LRG

 

Find Shorty!

Get a test light! They're cheap and very helpful if you slow down and think your way through problems. Consuming electricity requires two things: Voltage and ground. Just like a light bulb. Power through bulb to ground equals light (and drain on battery).

First. Make sure your ignition switch is OFF and not set to PARK. PARK will run your taillight and kill your battery. Hey, we've all done it...not all of us will admit it!

Make sure that your battery cables are clean. Make sure that your ground is good and tight. Take off your positive cable. Correct me if I am wrong - or this will be futile. Is there anything at all on an old CB that uses electricity while the ignition switch off? I'm thinking prolly not (clocks, etc).

Go with me on this....nothing is supposed to run with the ignition switch off. Hook you test light's negative clip to the battery's positive post and then touch the probe to the positive cable. If the test light lights up - matters not how dim - you have a short. Some run of power is finding ground. Head towards the fuse box - you gotta hunt it down.

Good luck! PM me if you get need to.

 

Thank you both for your quick reply!

The discharge happens overnight. I can buy a new battery on Saturday morning, start it and ride some Saturday, and sunday afternoon it's dead. Same goes if I charge the battery overnight, then reconnect the cables. 24 hours after a charge, it's dead as a door nail. Or should I say, 24 hours after connecting the battery to the system.

Never heard of tracing with the light, but it makes good sense! I will be giving that a try. I have, on prior motorcycles left the PARK on. I was careful to watch that on this one but it's a good idea! I've done it before!

You are correct. There is no clock or anything that I can think of that would consume power when in the key is in the "OFF" position. It sure does have a complex wiring harness for such a simple bike.

I'll try tracing down each accessory with the light and see what I find.

Thanks!

Brad

 

I think what Gumby was trying to tell you is that the fuse box should be dead without the key on. With the light in place pull one fuse at a time. When the light goes out, that's the bad circuit. It will cut down your tracing time.

 

I would check your circuit schematic for diodes. A diode, properly functioning, will allow current flow in only one direction (sort of an electrical "check valve". When bad, a diode will allow current flow in either direction, allowing a circuit that is normally "off" to slowly discharge a battery...just as if you'd left the lights on.

 

Think I got it!

I didn't have a test light, so I put my multi meter in parallel with the battery. I could see the battery voltage drop to 8.5 Volts until I pulled the connector going to the rectifier. I assume it is not usual for it to be draining on the battery all the time! The battery by it self or the battery without the rectifier showed about 12.8v

just 2 tires, a new chain, and a rectifier away from fun and good gas milage!

Thanks for your help!

 

Fastest way to tell if there is a current drain on the battery is to charge the battery back up, remove one of the battery leads, and place a current meter in series between it and the battery post. Be sure to hook up the polarity correctly, and start with the meter on the highest setting. I'm an electronic tech, but not much experience on bike electrical systems. But I am making an educated guess, that anything more than 20 mAmps of leakage (current) with the switch off is bad. You should be able to isolate the short by disconnecting lines to the lights, meters, etc.

 

Wow, thirteen years later and this thread is a suggested read ~ the O.P. never mntioned if he fixed it .

The 'leaky' rectifier is a serious problem on all older bikes, even the later production potted epoxy ones fail after sufficient time .

The good news is : they're cheap and easy to buy and mount on your old Moto .