Battery probs.

[DaveDanger]

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 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.

[J_C]

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?

[DaveDanger]

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.

[J_C]

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

[DaveDanger]

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

[J_C]

Yup.. I'm an idiot. I missed one important connection in the wiring diagram... I couldn't figure out why the drain was still ocurring even when I disconnected the connector before the switch. Low and behold.... I missed the connection... the one that goes to the Rec/Reg. I also neglected to see the melted tubing and the rust looking burn marks on the inside of the three wires coming from the Rec/Reg.

This is a really big bummer; looks like the seller flat out lied to me when I asked about any charging problems. Now I have a draining rec/reg which I'm pretty sure needs to be replaced, and a stator that doesn't seem to be charging well. Yay!


Thanks for the help Dave, I don't think I would have uncovered this nearly so soon had it not been for the help. I'll probably start a new thread when I'm done weeping.

[Rocketjock]

DD. I still haven't done anything about my "problem". But, maybe I don't have a problem. Question is; Will a small 12V battery like the one in the bike hold its charge after sitting for, say, three weeks or is this a natural occurance? The bike has started fine since and to be honest, it's one of the things I really hate about the 80 GS750ET is the battery is really hidden away and requires removal of the air box to get at. I know, I'm just being lazy. DD. The advice given is invaluable and I will definately use it to check for any leakage when I get a chance.

[DaveDanger]

RocketJock, I apologize for getting off track on your problem... I tend to read through these posts quickly, and sometimes don't pay attention to whether I'm commenting on the original post or one that comes in midway...
The battery I have in my GS850 was new when I installed it back in September of 05 even though it had sat on a shelf with the P.O. for a year before he gave it to me. It cranks mine up pretty easily even after sitting several weeks (as much as 5 weeks so far) at a time without moving. I think that ANY wet-cell battery large or small, will lose voltage if it sits long enough. It's simple laws of conservation. Energy tends to bleed away, friction tends to bring moving objects to a halt, etc.

Terminology can have us all at cross-purposes at times here as well... one poster asked if the battery was dead, or dying, you replied that it was not dead "Negatory. Battery hasn't gone dead. just not holding charge." In that case, I'd think you were both saying the same thing.... if it won't crank the engine, it's dead for all intents and purposes. My guess is that if you are on your third battery, and within 3 to 4 weeks of sitting, it won't crank the bike... I'd think you have a low voltage drain somewhere in the system.

How much time it's worth spending tracking down, is a whole nother story. Some folks would rather die than have even a small battery drain, like they'd be sleepless over 3 cents difference in their checkbook. On the other hand, there's folks that would just get a battery tender and keep it trickled up, feeling like if it gets them through the ride they want to do that day, they're happy.

If you're one to grit your teeth over a voltage drain (I am), try a few of the tests I mentioned earlier to J_C, and post back in and we'll wade into it with a clip on our nose and search till our eyes bleed

I'm always happy to find something to help on that keeps my mind of my dadgummed imperfect carbs.](*,)

[J_C]

Yeah that test and a wiring diagram is enough for even the least electrically competent of us to at least isolate where the problem is in the chain. Now what's causing the problem......

Thanks again DD

[wesleyweazel]

Battery

Usually a battery will read about 12.5V without the engine running. You should get 13.8V at about 3000RPM across the battery terminals while the bike is running.

Does your multimeter have the facility to check current. It will be marked by DcA (DC Amps ). If so connect it to the battery as follows. Disconnect the positive terminal of the battery. Securely connect the black lead of the multimeter to the positive terminal of the battery. Then connect the positive lead of the battery to the red lead of the multimeter. Make sure to start with the largest scale on the multimeter (10A). The red lead on the multimeter usually gets plugged into a different place (normally marked 10A) on the multimeter. You'll have to start the bike first and then disconnect the battery to check it. Otherwise you'll probably blow the multimeter up. This test will show you how many amps your bike is charging the battery at. This depends on how flat the battery is. If you don't get a reading or it has a negative sign next to it, try swapping the red and black leads around. WARNING: Do not check Voltage with the leads in this configuration. Do not leave the leads in the voltage jacks on the multimeter and try to test current draw. Voltage is always tested in parallel (across terminals). Current is always tested in series (interrupt normal circuit with multimeter leads). If the reverse is done it will fry your multimeter. Also never check resistance (Ohms) with power on the circuit. Usually a good idea to make sure by checking for voltage first.

Your manual should tell you how many max amps your stator can charge at.
IF you suspect a problem with the stator then check your manual on how to test it. I have an original Suzuki manual for my bike and it gives detailed step for step instructions on how to test the charging system.

This current draw test can also be used when the bike is switched off to see if anything is draining the battery while the bike is standing.

Sounds complicated, but isn't really. Just double check where the multimeters leads go. The stator has three wires and if its unplugged should give you a low value Ohm reading between either of the wires. If that checks out then start the bike with the stators wires still disconnected and test for AC voltage between all of the wires. My manual says 18v.

Hope this is of some help.