WHY DOES BATTERY KEEP DRAINING ON SUZUKI T500 ?

ericsattic · Last edited by ericsattic on Mon Mar 21, 2011 11:27 am; edited 1 time in total

Greetings board members. Here are the symptoms of my problem. Batteries slowly drain down until they are dead. I do not drive the motorcycle much but its started every couple of weeks and I drive two or three miles. Battery would probably drain faster if I drove it more. Battery drains more quickly if the lights and signal lights are used. If the bike is running with the lights or blinkers on and battery goes dead, the bike stops running. But when the lights and blinkers are shut off the motorcycle can be started and driven with dead battery. But if the lights or blinkers are switched back on, the bike dies... I can charge the battery or replace it, bike runs fine, but as I said the battery slowly drains until dead.

I read that a battery that drains may be caused by either a faulty AC generator / alternator / stator -AND/OR - the silicon rectifier. Based on what else I have read I believe the culprit here may be the rectifier. I do not have any electrical meters, etc... to test these electric components. So here are my questions:

Should I begin my attempt to solve the source of my battery drain problem by simply replacing the rectifier? Can someone confirm for me the rectifier is located right behind the blinker / signal relay on the T500? Does anyone have photos of the rectifier so that I can be certain about the component I am looking to replace? THANKS!

MR.CHocko · Posted: Mon Mar 21, 2011 1:59 am Post subject:

First you diagnosed the problem that the battery is not charging. First what I suggest you do is go and buy a cheap multimeter at walmart, Pepboys,etc. $8.00 is a lot cheaper then having to spend $250 for both a new rectifer and a stator. Then what I suggest you do is to start testing electrical components. Once you know what is bad then go from there. Both a bad rectifer and a bad stator will cause the problems that you are having.

ericsattic · Posted: Mon Mar 21, 2011 11:50 am Post subject:

CaptCatFish · Posted: Fri Mar 25, 2011 3:07 am Post subject:

Mr. Chocko is right. By a digital ohm/voltage meter from Wal-mart, connect the leads to the battery currently installed in the bike, duct-tape the meter to the tank, start her up and watch what happens to the voltage. You may even want to go for a ride provided you can safely focus on the road while glancing at the meter.

In my experience, the battery should read at least 12.5 volts or more when fully charged; drop to 12.3 or so when the lights come on, but go back up to around 13 volts or more when the bike is running at least 3-4K rpms. If you are not getting these upper values, the bike is not re-charging your battery at a sufficient level to overcome the drainage from the lights at lower speeds.

If its not charging, some one smarter than I am will have to chime in here about how to determine whether or not its the rectifier (i.e., voltage regulator) or stator/charging coil. I suspect the rectifier but can't be sure.

I hate electrical problems. Far more frustrating (to me) than all things mechanical............

CaptCatFish

Bikegeezer · Posted: Fri Mar 25, 2011 7:37 am Post subject:

KirkN · Posted: Fri Mar 25, 2011 8:29 am Post subject:

MR.CHocko · Posted: Fri Mar 25, 2011 1:46 pm Post subject:

With the bike running put the correct end of the meter to right terminal on the battery. Set your meter to volts and then check to see if it is charging. That should tell you if your stator is bad. The rectifer I believe you should take it off and do a test for resistance. IT should give you a specfic ohm range.

ericsattic · Posted: Tue Mar 29, 2011 8:05 pm Post subject:

ericsattic · Posted: Tue Mar 29, 2011 8:12 pm Post subject:

CaptCatFish · Posted: Wed Mar 30, 2011 1:18 am Post subject:

Give me a roll of duct tape, a can of WD-40, a gallon of bleach and all problems can be solved at least for a little while.

Careful the next time you go fishing. You've got some BIG blue catfish in the James and a couple of more rivers in VA that I can't spell (Rappahanock?). I have a friend there who consistently catches 50lb+ catfish. On second thought, I'm not sure how good a friend he is since he never offered to take me with him Sad

CaptCatFish

SPRHK · Posted: Wed Mar 30, 2011 6:35 am Post subject:

A battery in good condition will read 12.3-12.7 volts with the key off. If you are reading less than that, disconnect the positve lead on the battery & check again. If it still reads the same, then the battery is on it's way out. If the voltage rises once disconnected, you have a short somewhere, slowly draining the battery. Not really sure what the T500 charging rate is, and some bikes dont charge at idle, but as a rule, if the charging system is in good working order, it should charge at least 14 volts, if not more.

ericsattic · Posted: Wed Mar 30, 2011 7:05 am Post subject:

SPRHK · Posted: Wed Mar 30, 2011 7:20 am Post subject:

You dont need to ride the bike to test Fire the bike up, put your probes on the appropriate terminals of the battery and test accordingly.

ericsattic · Posted: Wed Mar 30, 2011 7:26 am Post subject:

SPRHK · Posted: Wed Mar 30, 2011 8:53 am Post subject:

I would fire the bike up, lights off, test battery at idle, slowly rev up to about 3000rpm, reading the meter. Then flip the head light on and do it again. I really dont think you need to rev it up to 4000-5000 RPM.