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Battery being Killed

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I have a dualsport wr450F converted by previous owner. The battery was cranking allright but half way into a ride i found it totally dead and even the start button redlight would not show. I kick started the bike which is HUGE pain and got it back home. Battery on test showed "OPEN CONNECTION" and could not be charged. I replaced it with a new battery that cranked the bike right up. Next ride only 5 miles into the ride I turn off the bike and switch it back on and no redlight or battery on the new battery. I get it back and same "OPEN CONNECTION" on the new battery too. I am not sure what is happening. Headlights work but nothing else. Fuse not blown. Switch seems ok. Any experience and advice would be appreciated. Battery is gone again. All i think is a short thats ruining the battery but no idea. Even if it wasn't being charged it would not go dead in 5miles

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you need to get a multimeter and get some readings from the bike... what is the voltage at idle and at the upper rpms that will tell us if it is even charging correctly

then get a milliamp reading between the battery and one of the cables that will tell us if its got an unusual draw. over 50 milliamps is bad

I suspect your battery is being overcharged and cooked like a baked potato

 

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On 6/29/2017 at 10:17 AM, cxr100 said:

you need to get a multimeter and get some readings from the bike... what is the voltage at idle and at the upper rpms that will tell us if it is even charging correctly

then get a milliamp reading between the battery and one of the cables that will tell us if its got an unusual draw. over 50 milliamps is bad

I suspect your battery is being overcharged and cooked like a baked potato

 

So voltages at the terminals is 6V not 12V when bike is started and red wire is disconnected from the battery. I also checked at the red and black wire under the tank and it shows under 6v with bike running. Not sure what to check next and what could be the fault. Funny thing though when the bike is running and the meter is connected for amps there is a charging current of 1amp that reduces when revved. Idle no start discharge is .2amps coz of taillight running. Bike starts fine and runs with the headlight on too.

B

Edited by avf

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Sounds very similar to the problem I had on my 2003 wr450. I had to replace the regulator/ rectifier.

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That's what I thought too but replacing it had no change :-(

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Stock Yamaha stator or aftermarket?       It is an important question because the stock Yamaha regulator ONLY works

with the stock Yamaha stator.   If you have an aftermarket stator (trailtech, etc) or the "ground has been floated" the

Yamaha regulator will NOT work.  

 

For dual sport conversions it is common to go to aftermarket stator or modify the stock one to get more power for

the lights.

 

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It was  a used stock regulator of ebay. ..funny thing even though the open voltage is about 6v. The battery seems to be charging ad I rode it about 50 miles  without issue so far.all this on the old regulator. Keeping fingers crossed

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Buy a brand new voltage regulator/rectifier and clean all grounds and check/clean all connections. I had the same problem with my 2003 wr450. Replaced regulator and it burnt out, bought new regulator and cleaned all grounds and connections, also put di-electric grease on all connections. No more problems.

Sent from my SM-G935V using ThumperTalk mobile app

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Seems to be doing ok. Hopefully get to ride and retest coming weekend

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Oh no it happened again. After about 100 miles of riding where the battery was fine, Yesterday the battery got killed again. Now this does not happen slowly it but within a quick ride of couple miles.

 

Where are the grounds I need to check ? Thanks

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Do all of your lights work properly?

I had an instance where I bottomed out my rear suspension and tore the wires in my tail light and didn't realize it because of the plastic housing I ran them in appeared to be fine. The wires were touching, making an incomplete ground and draining my battery. 

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I just dualsported me bike and the battery went dead on yesterdays ride. Thanks for the info. 

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I replaced the Voltage regulator from  wr250f and It seems to be holding better. Thanks all

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