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Is my battery dead? Is my charging system fried?

Posted: Tue Jul 31, 2007 12:33 pm
by guitar guru
I left my motorcycle for a little over a month (with gas stabilizer in it) and got back to find the cycle with starting problems. It wasn't starting after lots of turning over. Well I jumped it with a friend's car and all was well. I went to a couple places and it started up fine afterward, but then it wouldn't start up after leaving the DMV. I got another jump from a lady there, but in my rush to do it I connected the cables in reverse order and absolutely no power came through my bike. All the indicators were off, so I quickly disconected the leads and the indicators came back on but not enough juice to even turn the engine over. A couple of bikers came over and helped me push start it (I had no idea how easy that was or I'd have done it myself) and I made it home fine.

Now the battery holds a little charge but not enough to turn the engine over fast enough. After the ride home it seemed like the charging system worked, cause the battery had more juice in it than when I left the DMV, but not enough to start the bike. I push started it and took it out for a long ride today and same thing happened - it had juice in it, but not enough to turn the engine over fast enough for it to catch.

Is just my battery fried, or is it probable other parts were damaged too?

Sorry for making you read through all that.

Posted: Tue Jul 31, 2007 1:17 pm
by jonnythan
If you don't have a multimeter, get one from Radio Shack or Wal-Mart.

Measure the voltage across your battery while the bike is off. Then measure the voltage across the battery while you push the starter. Finally, measure the voltage across the battery with the bike running (if you can get it running).

BTW, when jump starting a bike with a car, LEAVE THE CAR OFF.

Posted: Tue Jul 31, 2007 1:47 pm
by tim conroy
You need to take your battery off and take it to the auto parts store and have it load tested.If you can get your bike started put the multimeter on the battery and rev to 2 grand.Se if your voltage goes to at least 13.8 to 14.5.Rev to 5 grand and see if it goes past 14.5. If it does than your r/r is bad.If at idle it is at least 13.6 your stator is good.Chance are your battery if at vault.

I have a similar problem

Posted: Tue Jul 31, 2007 2:37 pm
by jacquus
hey all hope you can help

I was riding when my bike "86 maxim 700" just died I was not to far from an auto zone pushed the bike there and they tested the battery and told me it was dead so I bought a new one put it in, and the bike went with out probs now 3 days later the same thing just this time I had no power what so ever I pushed it and no go so eventually I got a jump start and she started right up I went to auto zone and asked if they can check the charging he told me his machine is just set up for Cars with alternators and there is no way he can check my bike as it has a generator any ideas how I can check this, my light wasn’t even dimming when this happened, I parked the bike took the battery home and placed it on charge foe a couple of hours took it back and rode my bike home :frusty:

Re: I have a similar problem

Posted: Tue Jul 31, 2007 2:41 pm
by jonnythan
jacquus wrote:hey all hope you can help

I was riding when my bike "86 maxim 700" just died I was not to far from an auto zone pushed the bike there and they tested the battery and told me it was dead so I bought a new one put it in, and the bike went with out probs now 3 days later the same thing just this time I had no power what so ever I pushed it and no go so eventually I got a jump start and she started right up I went to auto zone and asked if they can check the charging he told me his machine is just set up for Cars with alternators and there is no way he can check my bike as it has a generator any ideas how I can check this, my light wasn’t even dimming when this happened, I parked the bike took the battery home and placed it on charge foe a couple of hours took it back and rode my bike home :frusty:
Sounds like your charging system is dead.

The way to test it is to start up the bike (sounds like this should be no problem, as you have the ability to charge the battery and it's holding a charge long enough to start it up) and measure the voltage across the battery while revving to ~3000 RPM.

You should see in the neighborhood of 13.8 - 14.2 volts. If you see more like 12 volts, then your charging system is dead and it's either the generator or regulator/rectifier.

Here's a link that will help you isolate the problem in the charging system. All you need is a standard $10 multimeter:
http://www.electrosport.com/Images/fault_finding.pdf

Posted: Tue Jul 31, 2007 2:47 pm
by jacquus
great thank you probably saved me taking it to a bike shop :D

Posted: Tue Jul 31, 2007 2:50 pm
by jonnythan
jacquus wrote:great thank you probably saved me taking it to a bike shop :D
Keep in mind that the dead charging system can just be a bad ground connection on the regulator or something like that. First thing you should do is check all of your fuses and carefully check all of the connections between the generator and battery.

Posted: Wed Aug 01, 2007 10:53 am
by guitar guru
Well I took the battery to Napa Auto Parts and had it load tested and it showed 12 volts normally and 7 volts under a load, so the battery isn't the problem. He said it had a pretty full charge too, but when I reinstalled it, the engine is still cranking over pretty slow. Is this the sign of a bad starter? What steps should I take next? When I hooked a multimeter up to it, the needle stayed at 10 volts the entire time from when the engine was off to when I revved to 5000 rpm, but if the battery is charged, then the charging system is probably working, because I never hooked it up to a trickle charger or anything else. So maybe my multimeter isn't working properly. I don't know what to do.

Thanks !!!

Posted: Wed Aug 01, 2007 11:28 am
by jacquus
Your advice helped -went trough every thing and OMF I will have to lash out for a new generator but lone behold when I traced the earth I found that some how one of the wires had been rubbed clean of insulation and made a dead short on the frame i taped it up and whao I got 13.8 v when the bike was running Thanks again :D

Posted: Wed Aug 01, 2007 11:33 am
by jonnythan
guitar guru wrote:Well I took the battery to Napa Auto Parts and had it load tested and it showed 12 volts normally and 7 volts under a load, so the battery isn't the problem. He said it had a pretty full charge too, but when I reinstalled it, the engine is still cranking over pretty slow. Is this the sign of a bad starter? What steps should I take next? When I hooked a multimeter up to it, the needle stayed at 10 volts the entire time from when the engine was off to when I revved to 5000 rpm, but if the battery is charged, then the charging system is probably working, because I never hooked it up to a trickle charger or anything else. So maybe my multimeter isn't working properly. I don't know what to do.
7 volts under a load? That's way too low. That means the battery is dead. Did someone at Napa tell you otherwise??

The battery should show no less than 10 volts under load. It should show well over 13 volts while the bike is running.

I think your charging system is not working and it's probably killing your battery.