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Battery discharging. any ideas?

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So i washed my bike a couple days ago and went to start it today and it was almost dead. and wouldnt start and died in the few seconds i was cranking it. I charged the battery and it starts fine. i did the free power mod and its over 14v at just above idle. key on its mid 12. what could be drawing power? i went through the whole troubleshooting thing a few times and everything is fine. i just cant find anything in the wiring that would cause it. i was spraying up under the rear fender for a few seconds but nothing crazy or more than normal. i let it sit after i charged the battery today and it dropped from 13.35 to 13.30 in just over an hour. this doesnt seem normal. what light do i use when i test for current leakage? Im not sure which setting to use on my multimeter either...

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Use the 10amp function on your multimeter first. Disconnect the neg and put the neg multimeter prob on the battery and the pos probe on the cable. If you don't blow the fuse then put the multimeter on to milliamperes and do the same test. Having your voltage drop from 13.35 to 13.30 in and hour isn't bad.do not turn on your ignition when doing this test

Edited by mickeydee

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A 100% charged battery (12V lead acid) should read around 12.8 VDC.  When the bike is running the voltage is higher because the stator/rectifier is outputting a higher voltage to charge/maintain the battery.  So after you shut down there is a "surface charge" in the battery and the voltage will read a little high.  As long as the battery voltage at rest (engine not running) is greater than ~12.5 VDC you'll be fine.

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AGM batteries hold a higher voltage.  Up to 13.2 when new.  Should really want to see it about 12.8 or better.  A battery that drops from 13.35 to 13.3 in 1 hr after charging is just about perfect.

 

Yes using a meter to measure amp draw (current leakage) is the way to troubleshoot a discharging battery.  There is no way it is drawing 10 amps, but always good to start on a high scale and work down.  You want to test for current draw with the key OFF.  You may also want to test for current draw with the key ON but you will have to disconnect known loads such as lights, instruments, ignition

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so i checked it and its about 1.5 on one and 1.3 on the other. normal apparently? i still dont know why the battery would've died in just 1 day of sitting. but i kicked it and it started up in a couple kicks. but it died the rest of the way while it was idling since i didnt go ride it. I've let each of them sit for multiple days with no problems. i just figured something had to be wrong. i'll do a load test on that battery on thursday...

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The current draw test should show under 1mA. 1.3 to 1.5 is over. Something is sucking power from your battery other than the clock

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From FAQ.

 

"For an E bike you are looking for less than 1mA current leakage. For the S and SM with LCD instrument display, current leakage up to 2 mA has been found to be normal."

 

Plus consider the accuracy of measuring in milli amps, 1.3 to 1.5 mA is not bad. The next time you wash the bike, take a look at the LED tail light.  It does not take much moisture in switches to allow enough current to pass to illuminate the LEDs.  That may have been the source of your problem.

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Suzuki E service manual says 1 Ma.  But Suzuki neglected to revise the number when they added the LDC "keep alive" current for S/SM models. Research, observation, history and your own recent tests support that 2 Ma is entirely normal or S/SM.  It is why batteries go dead in 3 or 4 weeks.  Not a problem if the motorcycle is used regularly. Nothing you can do about it unless you disconnect the battery.  The advise to keep the DRZ on a battery tender is valid advise.

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From FAQ.

 

"For an E bike you are looking for less than 1mA current leakage. For the S and SM with LCD instrument display, current leakage up to 2 mA has been found to be normal."

 

Plus consider the accuracy of measuring in milli amps, 1.3 to 1.5 mA is not bad. The next time you wash the bike, take a look at the LED tail light.  It does not take much moisture in switches to allow enough current to pass to illuminate the LEDs.  That may have been the source of your problem.

ok. i'll make sure to not spray under there again. i'll pull off the lens tomorrow and check for condensation. i checked all the connectors and sprayed contact cleaner in all of them so it might have been that. i didnt realize that the water could turn the light on...

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Suzuki E service manual says 1 Ma. But Suzuki neglected to revise the number when they added the LDC "keep alive" current for S/SM models. Research, observation, history and your own recent tests support that 2 Ma is entirely normal or S/SM. It is why batteries go dead in 3 or 4 weeks. Not a problem if the motorcycle is used regularly. Nothing you can do about it unless you disconnect the battery. The advise to keep the DRZ on a battery tender is valid advise.

that spec "1mA "was quoted from an s model manual. I'll do a test on one this week and see what I get

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mickey - I think all the service manuals say 1ma.  But tests and reports here on TT for 13 years says 1.5 to 2 is the norm for S/M.  The E only leaks current thru the RR.  The S/SM has the same RR plus the instruments so it has to be more.

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Have you load tested the battery? How old is it?

pretty old. im surprised i havent had to change it yet. i could be as old as 06. i swapped it from an 06 S that i had. it could be newer but i have no idea. im going to test it tomorrow...

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ok. i'll make sure to not spray under there again. i'll pull off the lens tomorrow and check for condensation. i checked all the connectors and sprayed contact cleaner in all of them so it might have been that. i didnt realize that the water could turn the light on...

I don't think it was the tail light that Noble was talking about, it's the brake light switches. If moisture gets on the switch contacts it can allow a small current to flow. Not enough to light a normal bulb but enough for LED's to start to light up.

 

Just for info on normal battery drain...

 

2mA drain for 1 week is (0.002 Amp x (24hrs x 7days) = 0.336 A/hrs power lost per week, which isn't a massive amount.

To lose 1/2 the capacity of your bikes battery (6A/hrs - assuming a healthy battery and a full state of charge) should take almost 9 weeks, and it should still start your bike unless it's a BB stroker or something. 

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pretty old. im surprised i havent had to change it yet. i could be as old as 06. i swapped it from an 06 S that i had. it could be newer but i have no idea. im going to test it tomorrow...

The thing I've learned about batteries is that they NEVER  get better, they just slowly get worse...until you're stranded 45 miles into the bush one day......as I well know:)

 

My experience coincides with DRZDick's assessment above. FWIW, I installed a Shorai a month ago and so far it has met my expectations, but it does cost more, think I was into it for about $135. Spins the motor beautifully and the component quality is very nice!

Edited by shuswap1
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pretty old. im surprised i havent had to change it yet. i could be as old as 06. i swapped it from an 06 S that i had. it could be newer but i have no idea. im going to test it tomorrow...

 

Possible that the battery is just tired and on the way out. Have you got a good one that you can swap it over with for a while?

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