My battery is being drained, how can I figure out why?

A while back (prolly 4 months), while in a hurry, I hooked up my battery backwards. Hit the start button... pop. SO, that one is done... I recycled it. After replacing a 20a fuse, I was able to jump start the bike to verify that I had not killed the starter. Fast forward to last Wednesday...I install (properly) a new Shorai lfp04 battery. Bike fires right up... idles for a few mins, I shut it down. Now, today.... battery is dead and registering 0.0vdc on my meter. Suspecting it's not a faulty battery, I pull the battery, put it on a 2amp charge for 30 mins. I put it back on the bike and connect my meter between the negative cable and the negative post with the meter set to read a max 10amps... meter reads 10.43amps !

Did I FRY something which would leave a circuit open that would cause this kind of draw when the bike is sitting there NOT running???

No lights, no blinkers... only electric starter, charging system and whatever controls the spark. Bike is TXC450

Simulpost on TT... just FYI...
Thanks for any help!!!
Andy

Id leave you amp meter between the earth terminal and the battery and start pulling fuse 1 by 1 and see when the current drops, then find what that fuse powers. Or start disconnecting things and see when the amps drop.

Terribly sorry Dean. I'll not do that again. I don't generally visit TT (don't like the site or its leaders), but I thought this issue was rather broad and that I might get some good information to help me out by posting there.

Good call, I can try that. The TXC is really simple, only two fuses, so that should be super easy.

As I understand it from looking at the manual, there's only the CDI, coil, condenser, voltage regulator and stator.... I'm guessing its going to be the voltage regulator.

If you don't have an amp meter a 12volt test light works if put in series between batt terminal and cable end. The light will light while the drain is present. Once you find the circuit by pulling fuses you can replace the fuse and start unplugging components on that circuit until you have the booger isolated.

Hi Andyman. I just read your post a few times. Did you have any problems before you connected the original battery incorrectly? and have you methodically gone back over all the items/connections you have touched? I've just fitted a lithium battery to my SMR and one thing I did glean is that once fully discharged they do not recover fully, if at all. Which even when you find the problem, might lead you to think it is still there. You might be lucky, hope so.

Hi Moto, I did not any any issues with power drain before hooking the original lead acid battery up backwards. After hooking it up backwards and hitting the start button, and realizing what I had done, I knew that battery was destroyed; therefore I recycled it. The bike is running fine, I only noticed the problem when I put the new lithium batery in and it got drained. Since charging the lithium battery yesterday, it has maintained it charge sitting there unhooked, so maybe it'll be okay. Even with this new battery that may not fully recover, I can't see it causing a 10amp draw at rest. right?

I am going to try lankydoug's test light method since it should be easy to watch out of my peripheral vision.

Thanks all,
Andy

Hi, and no, you should have zero draw unless you have an alarm or something add-on, and that would only be milli-amps. Test light method sounds good but I'd always use a volt meter if you have one. Grab an assistant You might want to use an old 12v battery, just in case you cause another short whilst testing - just in case! Good luck, hope it's a cheap fix.

With the test light or volt meter hooked in-line or in series with the positive batt cable the light or meter will have enough impedance to prevent damage. if there is a milliamp draw from a memory chip the light will barely glow a dim orange. A 10amp draw will light it up.

I gotcha Dean. No worries from me. This is my preferred home on the "intarwebs" for bike stuff. Just wanted to make sure I hadn't hacked you off.

With that said, I understand the tech issue, and agree wholeheartedly.... I don't like embedded links littered through a post. I tend to read with my mouse following my eyes and it's irritating to have links popping up and blocking what I'm trying to read.

I appreciate that you aren't trying to monetize this site through the use of ads. It is very annoying.

k. So, I've torn the whole front end of the bike off... to get the tank loose. I wanted to clean and grease the head bearings anyway...

Using the basic test light method referred to above (test light in series with the negative post of the battery) I'm seeing that when I unplug the voltage regulator, the test light led goes out completely. When unplugging other random connectors, the light stays lit. Safe to assume the VR is the issue? When left plugged in, and one connector from the stator that provides two wires to the VR is disconnected, the light also goes out (green wire and yellow wire from the stator, yellow wire and white wire to the VR).

It is very common for reverse polarity to zap a voltage regulator, I'm pretty sure you nailed the problem down. I would recheck with the light after you have installed a new voltage regulator.

My copy of the 2006 Workshop Manual indicates your VR is bad. On page M.16 there is a procedure to check it with a multimeter. If you don't have a copy of the Workshop Manual, Google it, or try PDF Service Manuals.

Also take a 50 A. car battery charger on boost setting and attache it directly to the starter and make sure it spins.

Good luck.

I hope so lankydoug. From what I can tell in looking at the wiring schematic in the workshop manual, the battery is on an isolated circuit which is only used for starting the bike. The parts associated with the battery are:
1. Starter
2. Battery
3. Clutch microswitch
4. condenser (capacitor?)
5. Voltage Regulator
6. start button
7. fuse panel

Hot flows everywhere except to the clutch microswitch and the start button. There is a diode that protects them from a backfeed of power. Although hooking the battery up backwards could have sent hot current to any of the components outside of the isolated circuit (since everything shares a common ground), since they do not get + current from the battery, they received + through the ground and + through their normal wire... I doubt that completed any circuits or caused any problems outside of the isolated battery circuit. Therefore, the only parts that could have been affected are: 1. the starter, 2. the condenser, 3. the voltage regulator, or 7. the fuse panel. I'll do a little more testing to be absoloutely sure but I'm pretty sure it's the voltage regulator.

Anybody got a spare???

Oh a whim, I snagged this off fleabay.

http://cgi.ebay.com/ebaymotors/ws/e...id=p4712.m2000054&item=230560649144&viewitem=

It looks identical to the one I pulled off the bike.

A reversed polarity will allow diodes to conduct, and if the circuit is not designed for this it will short the diodes and allow current flow when it is not supposed to happen after the battery is hooked up correctly again. Since the voltage regulator is the most likely place for diodes to exist in this circuit, it is the logical victim.

So I got the VR/RR from ebay in the mail a day or so ago. plugged it up, ran my amp draw "test" with my test light, and no light was lit. I plugged up the battery and monitored it with the meter for 10 minutes or so and noticed no voltage drop. I left it plugged in over night and the battery didn't drain AT ALL. so I'd say the VR/RR was the culprit.

now this one I got off e-bay says it's for 50-150cc bikes... no idea if my bike will fry it... but it was worth the $14 gamble to me... since the husky VR/RR was around $60.