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Battery probs.

  • Thread starter Thread starter Rocketjock
  • Start date Start date
R

Rocketjock

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My 80 GS750 had a totally dead battery a year ago when I acquired it. Bought a new one and didn't have it running much in that year due to some surgery I had to go thru. When I finally was able to get back at it several months ago I found the battery dead again. Purchased another new one and, sure enough, after the bike sat for a couple of weeks, the battery was run down enough so that the bike wouldn't start. Am I just having a run of bad batteries or could there be something else here? Where do I start and what do I look for? I have a new Clymer manual so perhaps it can help me out but first I thought I would query yous guys. The battery may still be under warrenty so I can probably get one for free but what if it's the alternator or regulator?
 
Negatory. Battery hasn't gone dead. just not holding charge.
 
If you don't have one already, head over to sears and buy a digital multi-meter. You can get an decent one for about 30 or 40 bucks. Simple tests like parasitic draw and a voltage reading while the bike is running will point you to the problem area.
 
Excellent advice on the multitester. You might discover that there's a minor short circuit somewhere that's draining the battery. You might find that the charging circuit is not putting out enough voltage. The wiring harness could have cracks that prevent enough amperage from flowing back to the battery, etc. etc.

All these things can be tested for with a good multitester. GS's have notoriously problematic charging systems, and the multitester will help you determine if yours is one of them. Having said that, there are plenty of people here who've never had a charging problem (myself among them)...

One suggestion ... if you find that everything checks out and you can't find an obvious problem, you might want to consider adding a master power switch to the battery (which cuts it off from the entire electrical system). Then when you park the bike you'll know for certain that there aren't any slow drains happening while it sits...

Good Luck,
 
Thanks for the advice, guys.
I do have a multitester but am not sure where to look. Perhaps the Clymer book will tell me. I do know that with head and taillights alwas running, there's a lot of juice being used up even before it gets to the battery.
 
Not to insult your inteligence but, are you turning the key off to the right or to the left? If your turning the key to the right and removing the key, the tail light will be on. Sidenote, when it's running do you keep the tach at 4000 rpm or more as much as possible? Putting around at 2000-3500 rpm will not recharge the battery as fast as the lights are draining them. I find myself guilty of that one every now and then, but am getting better. Just keep it in a gear that will keep the rpm's up. When you get your multi-meter, set to ohms and remove the battery wires and test between them for shorts, if reading goes up you've got problems, possible shorted stator. Keep us informed.
 
arveejay said:
Not to insult your inteligence but, are you turning the key off to the right or to the left? If your turning the key to the right and removing the key, the tail light will be on. Sidenote, when it's running do you keep the tach at 4000 rpm or more as much as possible? Putting around at 2000-3500 rpm will not recharge the battery as fast as the lights are draining them. I find myself guilty of that one every now and then, but am getting better. Just keep it in a gear that will keep the rpm's up. When you get your multi-meter, set to ohms and remove the battery wires and test between them for shorts, if reading goes up you've got problems, possible shorted stator. Keep us informed.

Can you be more specific? Which setting on ohms and what should I be looking for? Should I just put the red connector to the red battery wire and the black to the black?
 
My meter only has 1 setting, I would set it at lowest scale, you should get no reading. Yes black to black and red to red. You can fully charge the battery with no cables hooked up, check the volts let it set overnight and check it again in the morn. With no cables hooked up the reading shouldn't change.
 
I got no reading across the board for any of the ohm settings on the battery cables. Battery is reading as fully charged at 13.27v. I'll see what it's at tonight.
 
Three faulty batteries in a row would not be impossible, but the odds are so small that I'd be looking for a much more plausible explanation. Here goes...

A faulty reg./rect. unit will allow your battery to slowly drain of power while the bike is parked up.

To find out if it is the reg./rect. that is causing the battery drain, simply disconnect the reg./rect. from the battery when you park the bike.

Then see if it holds its charge. If so, the reg./rect. is your problem. If not, then you have some other cause of the battery drain, eg. a short in the wiring somewhere else.

But check out the reg./rect. first.

Mike.
 
UncleMike said:
I got no reading across the board for any of the ohm settings on the battery cables. Battery is reading as fully charged at 13.27v. I'll see what it's at tonight.
Battery not connected all day, and now reading at 12.85v. Still no reading on the ohms at the battery cables. Seems as though the battery is just dead. Would it be better to ground the OEM R/R, or install the Honda CX500 R/R?

More than twelve hours later and the battery is down to 12.80v.
 
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UncleMike,
Go a tiny bit further with the voltmeter check if you would. To start with, consider that a battery will have its highest possible voltage reading as soon as you disconnect the charger. It WILL drop some to a nominal voltage after it's been disconnected for several hours. I'd personally take the first reading at least 4 hours after you've disconnected the charger, then again 8 hours after that to see if it is losing voltage. The possibility exists that the battery has been ruined (Its capacitance, or ability to hold a charge) by the constant draw on it, if that is indeed the problem.

Next step, check for a voltage drain in the wiring. With the battery fully charged and the key switch OFF, disconnect one cable from the battery, preferably the ground. Set your meter to DC voltage, at a higher range than 15 volts. Connect one meter probe from the disconnected cable end, and the other cable to the battery terminal post. The polarity is not important for this test, but if it makes you feel better, connect the black test lead to the battery post and the red lead to the disconnected cable end. If you see ANY voltage reading on your meter, there is a drain in your wiring. You should not see ANY voltage in the electrical system wiring with the key switch turned off. The meter should read as if you were testing voltage in a popsicle stick.

If you read voltage in this test, begin looking for your drain by pulling your fuses one by one until the voltage drop goes away. That will point you in the direction to continue searching.

Post back with results.
 
Thanks Dave!!

I am having a similar issue documented here: http://www.thegsresources.com/_forum/showthread.php?t=90406

I thought I was just having a charging issue until I went out today and tested the battery.... 2 days ago it was 12.5 and today it was 9.5 I immediately disconnected the battery before it got below 9 (that kills it right?)

Anyway now I know I have a charging issue AND some sort of parasitic draw. I opened the fuse box and saw that my signals fuse had blown out and been bypassed with some foil, but that wouldn't cause a draw, right? I'll go out tomorrow and start the test you described above.

I love these threads.... extremely helpful
 
Can I just add something to this debate, regardless of whether there is a draw on the battery or not, if you leave the bike untouched for a couple of months then there is always a risk of deterioration over time. For the cost of a battery you can get a decent charger, like an optimate, that will not only keep your battery charged and serviceable whilst not in use, but it can also bring back to life some batteries that have been given up for dead.

Basically if your going to leave the bike for more than a couple of weeks then put the battery on the optimate, they come with a moulded connector that you can wire into the fuse box to give you a simple quick and easy connection point. The electronics in the charger ensure that the voltage is monitored and as soon as it drops below what the unit considers safe, it begins a controlled trickle charger.

http://www.accumate.co.uk/it010003.html

Is their web site, I'm sure you can get them, or an equivalent, in the states.
 
J_C, the "Magic" about the 9 volt reference (or actually 9.6 volts) is that is considered the minimum voltage required to turn over a standard 12 volt starter. That's assuming all other things are working properly.

For your purposes, the battery voltage dropping below 9.0 volts isn't a problem in and of itself. You can take a brand new, fully charged battery and load it down till the voltage drops below 9.0 volts and not cause a problem. You simply desire it to charge back up as quickly as possible. When the voltage drops down to something below normal 12.75 volts and STAYS there, either because the charging system isn't functioning correctly, or because a drain is keeping it low...that's when the damage is done. A battery that stays at a discharged state, will quickly develop what is called a "sulphated condition". It no longer will be able to hold a charge, even if you charge it frequently. The damage is done by that time.

The "Optimate" and other low amperage trickle chargers are not a bad idea if your system has a tiny drain, or a weak charging system and you simply can't cure it regardless of the time spent troubleshooting. But start using it early in the life of the battery. Don't allow the battery to spend a lot of time discharged.

A simple manual trickle charger that's very inexpensive, can be built from components from Radio Shack... I did it 20 years ago for less than $10.00. Obtain a plain 12-14 volt, 500 milliamp transformer (A small square plastic box that plugs into a 110 vac outlet and has a 5' pair of wires out to a mini or sub-mini jack to power a kids toy/radio etc). 500 milliamp is 1/2 an amp, sufficient for a trickle charger. You can either crimp on a pair of alligator clips to connect it to the battery terminals, or like the Optimate and others, you can install a polarized quick-disconnect that permanently installs into the fuse-box or battery posts and allows you to plug-in the trickle charger in a few seconds without removing the seat or side cover or anything.
My problem at the time was money. My battery had a few years on it, and it had grown weak enough that even with the bike's charging system working properly, it was be too weak every morning to crank the bike. I "harvested" the transformer from one of my kids defunct toys, and fabricated the pigtail to permanently connect to the battery posts from terminals and such that I had in my toolbox already. The only actual expense I had in the whole thing was about $0.99 for the polarized plug-set to make the quick-disconnect. I was working for my Dad at the time, and anyone who's ever done that knows that cash does NOT flow like water into your pockets :oops: It worked like a charm and stretched my battery life through that winter till I could afford to buy a new battery. I still have that little charger and use it on an old beater pickup that I have out back that sometimes doesn't get operated for weeks or longer on end. A charge output of anything less than 1 amp will charge a battery fine without any fear of overcharging or overheating, even if you forget it and leave it connected a day or so too long.
 
Good info! I went out and purchased a battery tender... now... I performed your test...

I have a 0.03v parasitic draw that goes away when I pull the main fuse.... All I can tell from the wiring diagram is that there is a connection with the 10a fuse below it (Starter?) and then there is a red wire to the ignition switch. Anyone have any ideas on what to do now?
 
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J_C, Sounds like you're on your way to finding the problem :)
You've defined the draw location in a gross sense, and need to pin it down a bit more tightly. Sounds like you've already eyeballed the wiring diagram which should show you you specifically what that circuit is for and anything else that may be tagged onto that circuit. To find the one cause, you need to eliminate everything else. You mentioned the starter itself and the starter switch, and one of those could easily be the problem. Just for a quick and dirty check, disconnect the cable at the starter, and see if the draw goes away, if so, check and clean your ground to the starter, and thoroughly clean and insulate the connection for the positive cable at the starter. Unfortunately, it may be an internal problem which won't go away as easily, may require some disassembly and possibly a re-wind to eliminate. If the draw doesn't go away when you disconnect the starter, then back up to the slightly more time consuming step-by-step method and go through it logically.
Looking at your wiring diagram will show you the specific wire color codes that go to the starter switch, find those wires behind the headlight in the bucket and they will somewhere, in that spaghetti-wad of wires, be connected with push-pull bullet connectors. Disconnect at least one of the wires going to the starter switch and re-do your battery draw test. Ideally, you want to first test the wire going into the switch, then separately, the wire going out of the switch to the starter relay. If the voltage draw disappears when you disconnect the wire into the switch, you've determined that it is still "downstream" of your disconnect. Reconnect that bullet connector and go to the wire going out of the switch and test again. If the voltage drop does NOT go away, the switch is the problem, if it does, it's further downstream. Am I making explaining it well enough to make sense?
You simply continue down the wiring until you no longer find the voltage draw, it's the last previous thing you tested, basically.
I'd almost be willing to bet that it's going to be the starter itself or the starter relay... it is an electromechanical device that takes a small amperage circuit (through the starter switch on the handlebar) and uses that to connect together much heavier cables directly from the battery to the starter. A starter relay is wound internally as an electromagnet (Lots of wire internally) and it can very easily begin to draw a tiny amount of current and bleed it to ground in a fashion that would kill a battery over time. Personally suspecting that relay... I'd probably start there if this were mine to figure out. If that didn't prove to be the case, then I'd go through it step by step, but sometimes a leap of intuition is worth following in the interest of time.
There are a few other things to consider, but in the interest of brevity (?) I'll stop here and let you see what you can find, and if it the cause eludes us, we'll come at it from yet another angle.
 
Dave, you're fantastic. Thank you for the help! I'll start running through this tonight. Do you ususually keep the multimeter in series between the negative lead and the negative terminal? Or do you reconnect that and test the draw at the point where you've broken the circuit? I would expect the latter but I wanted to make sure.

These wiring diagrams are pretty much like woah. Or like woe. Either/or. I can follow it to the starter but after the starter switch it looks like it interacts with some of the wires coming from the other fuses that weren't creating the draw...


Also, edited above post. the draw is 0.03v, not 0.3v
 
Leave the multimeter in place at the battery post and cable. You can actually leave it there the entire time you're working on disconnecting and reconnecting wires and whatnot. If there are other circuits tied in to the starting circuit... disconnect those one at a time as well and check your meter. Any one of them could be the culprit. As long as they test OK, reconnect them and continue on.
Happy to assist :)
 
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