Battery draining when key is turned

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Joined
Dec 18, 2017
Messages
7
Location
London
After some advice....

An issue no doubt most Mille owners have heard or dealt with before...My RSV 2002 Mille is draining my battery. Have a smart battery with Volt reader fitted, battery is 100% it holds its charge off the bike and when sat on my trickle charger no problem. That’s great for day rides but not much else. When the bike is at idle battery is putting out 13 to 14 volts as expected. The issue occurs when the keys are put in and turned, lights come on etc then battery instantly drops all charge and only just turns over which is ok for once but if it cuts out it won’t have the power to turn the bike over. Battery is only few months old, i forgot to put it on trickle charger couple days after replacing it and when I went back to bike a day later it was dead so had to recharge it, bought the new battery as the one time I didn’t put it on trickle charger after buying the bike the old one did exactly the same thing. Any suggestions would be much appreciated, is it alternator, regulator?? Thanks
 
It could be you have a short somewhere. Do you have a circuit tester voltmeter etc. You need to check for a drain, it needs to be done circuit by circuit, it will be large if it's ripping through batteries that quickly, it tends to be the alarm (they were ***** when new, they short out frequently) other places to look is any wiring modification, could even be a broken bulb...
 
Thanks, it doesn’t have an alarm fitted, coupe of people have suggested that it’s the battery but it’s literally losing all charge when the keys are turned before even attempting to turn it over so. When you then turn the keys back off the charge comes back (that’s going off the readings on the battery’s built in indicator. So your solution makes more sense to me....the bike is fitted with aftermarket indicators front and rear with aftermarket relay (to control flash speed), luckily I was sold all of the original parts with it. Could this be a possible cause??
 
I have never seen a battery with a volt meter in it! So I have to take you word for that. Anyhow charge can not disappear and reappear in the way you describe. So there is some thing in your discretion that cannot be correct. Anyhow, as Harts says if you have more than 12.5 across the battery terminals the battery should be charged enough to start the bike. If you can start it and one it is running over 2-3 thousand revs you should get up to 14v across the battery if it is less than 13 v then battery is not being charged. Figure this first before going further. If you can’t start it recharge battery, if it still won’t start check ground connection, I.e. -ve to the frame or the Starter solenoid. If it still won’t start change the battery again. Buy a Yuasa or a proper battery without any gimmicks on it! Tell me how you get on and I’ll talk you through the rest.
 
When I say battery charge disappearing then reapearing that’s probably not a great way of describing it. Essentially there is and issue somewhere that is draining the battery quickly when left stood, and when keys are turned in the ignition during the process of the lights and display coming in it’s rinsing the battery to the point where it struggles to turn over. When the bike is turning over the battery is putting out 13.5 - 14 volts so the issue as I would understand it is not the battery or the charging side of it. Having read some other bits and from Hertsrvr’s info I may take all LED indicators off which includes a LED tail light conversion all fitted wit resistors and Aftermarket relay and replace it back to original parts, having spoke to the previous owner he said he had issues after fitting all the bits (but as he always had it on trickle charge and only did the occasional short ride it was never an issue to him) maybe they’re pulling to much power from the battery??
 
When I say battery charge disappearing then reapearing that’s probably not a great way of describing it. Essentially there is and issue somewhere that is draining the battery quickly when left stood, and when keys are turned in the ignition during the process of the lights and display coming in it’s rinsing the battery to the point where it struggles to turn over. When the bike is turning over the battery is putting out 13.5 - 14 volts so the issue as I would understand it is not the battery or the charging side of it. Having read some other bits and from Hertsrvr’s info I may take all LED indicators off which includes a LED tail light conversion all fitted wit resistors and Aftermarket relay and replace it back to original parts, having spoke to the previous owner he said he had issues after fitting all the bits (but as he always had it on trickle charge and only did the occasional short ride it was never an issue to him) maybe they’re pulling to much power from the battery??

OK, If fitted correctly, I would not expect the indicators to be a big load or drain the battery when off. You may have some other issue there.
 
So I’ve done some digging around, tested the battery with a multimeter as didn’t 100% trust the battery’s built in display, and the battery is fine showing good volts and can turn the bike over so the battery’s power is good. Kept the multimeter connected to battery and turned key in ignition, vaults plummeted and battery began to drain, charged the battery up and disconnected a few of the obvious connections (indicators, headlight, tail light, regulator), checked fuses (all fine) with multimeter attached turned key in ingnition, and a slight drop in volts as you’d expect but it was steady, re connected the connections one by one, as soon as the headlight was reconnected...voltage dropped and battery began to rapidly discharge. Any thoughts/help?? Thanks
 
INTRODUCTION:
The following procedure must be performed when refitting the battery onto a vehicle with the MARELLI instrument panel (identifiable by the + and - buttons to the left of the display). This procedure is necessary to prevent the instrument panel from remaining in the "awaiting memorisation of 2nd key", causing it to consume 20 times more current than normal.
The problem is caused by the instrument self-resetting and then waiting for a key memorisation procedure (even if it has already been performed), remaining in standby mode with this function still active. The resulting high current consumption will drain the battery completely within 3 or 4 days if the vehicle is not used.



PROCEDURE:
After disconnecting the poles of a battery on an RSV 1000 V2 with Marelli instrument panel, after reconnecting, perform a key-on, wait at least 15 seconds without starting the engine then switch the ignition off.

For more precise testing, connect a multimeter set to current measurement to the battery poles: at key-on, current consumption drops from 45 milliamps to 1-2 milliamps after approximately 15 seconds.
Obviously, when the multimeter is disconnected, it is as if the battery poles were disconnected again, so the aforementioned procedure must be repeated without the multimeter.
Someone sent this to me. Will try on day off
 
Having exact same prob on my gen 2

It’s a pain in the arse mate, hoping there’s a simple solution rather than having to rip out the full electric rig, electrics are not my area steer clear of them, can see it being an expensive one
 
If it's just the headlight you have to identify the fault more closely. Check the bulbs, if broken they can short. And the wiring and the switch.
 
Battery issues

So I’ve done some digging around, tested the battery with a multimeter as didn’t 100% trust the battery’s built in display, and the battery is fine showing good volts and can turn the bike over so the battery’s power is good. Kept the multimeter connected to battery and turned key in ignition, vaults plummeted and battery began to drain, charged the battery up and disconnected a few of the obvious connections (indicators, headlight, tail light, regulator), checked fuses (all fine) with multimeter attached turned key in ingnition, and a slight drop in volts as you’d expect but it was steady, re connected the connections one by one, as soon as the headlight was reconnected...voltage dropped and battery began to rapidly discharge. Any thoughts/help?? Thanks

Good progress :thumbup

Are you measuring the battery voltage directly across the battery terminals or from ground/frame to +ve? If you are not measure directly; volt drop on the -ve side can distort the reading on high currents.
In any case it would be interesting to know what voltage you have between the battery -ve and the frame/ground when you repeat the tests above.
The lights are The biggest drain on the battery (other than the starter) they can take between 5 - 8 amps or more when on. Is there a difference in readings from low to hi beam?
Do you have standard lights fitted? no LED or HiD?
can you measure the current, without blowing up the meter :)?

Also I assume you did theses tests without the motor running? what difference does it make when you start it?
 
Last edited:
Good progress :thumbup

Are you measuring the battery voltage directly across the battery terminals or from ground/frame to +ve? If you are not measure directly; volt drop on the -ve side can distort the reading on high currents.
In any case it would be interesting to know what voltage you have between the battery -ve and the frame/ground when you repeat the tests above.
The lights are The biggest drain on the battery (other than the starter) they can take between 5 - 8 amps or more when on. Is there a difference in readings from low to hi beam?
Do you have standard lights fitted? no LED or HiD?
can you measure the current, without blowing up the meter :)?

Also I assume you did theses tests without the motor running? what difference does it make when you start it?

Thanks for the detailed reply 👍🏼

Did the measurements across the battery terminals with the engine off.
Have standard lights fitted, did have led tail light fitted but I’ve gone back to all original parts.
I’ll measure the current and get readings with engine on and off and high beam/low beam.

I’ve had a few people tell me it’s just the battery, it’s a junk get a yuasa ttz14s. But even a bad battery wouldn’t have thought it would discharge that quick?

Did test the charging system Haynes says between 13-15 volts while at 4000rpm is standard, conflicts with some stuff I’ve read. Reading while at idle was 13.80 roughly when held at 4000rpm reading dropped to 13.30 is a drop expected or should it rise?

There is some mod wiring going to the regulator, there has been a connector removed and wires spliced into it, haven’t tracked where the go to but it would make changing the regulator a pain, I know the previous owner had an info rad fitted (wasn’t on when I got it but he gave me it) not sure how they set up with regards to being wired in.
 
Ok I look forward to your new readings.

The connector by the regulator can often be an issue for charging and it is not a bad idea removing it as long as the connections are well made. Essential as a lot of current is flowing, any poor connection here will lead to grief. Also it is a very good idea to increase the size of the -ve or black wire from the RR to the battery, as volts dropped here will reduce charging efficiency. Battery voltage dropping a bit at higher revs might just be an indication that RR is regulating more at these revs, depending on how measured. My Tuono volts on dash, use far right button drop similarly.
 
Have you changed the starter button switch gear or tried to bypass this by shorting the starter solenoid .to see if you have healthy start.


..I used to have a dodgy start button take apart and clean and use some dielectric grease then Try again
 
Have you changed the starter button switch gear or tried to bypass this by shorting the starter solenoid .to see if you have healthy start.


..I used to have a dodgy start button take apart and clean and use some dielectric grease then Try again

I believe the issue is battery discharging not Bike starting so I doubt if this will make any difference [emoji74]
 
Charge the battery off the bike, disconnect the charger and measure the voltage. It should be 13.8 to 14,4 volts
Connect a headlamp bulb to the battery and measure the voltage, if it is below 12v the battery is fubar
 
TommyT and any others interested, work has got in the way of making quick progress but the problem has fingers crossed been solved, not believing that I had an alarm fitted I put that thought aside, however when fiddling about with wires I found one stuffed out the way funnily enough with an LED on the end, the alarm LED. When and whoever took the alarm out wired it back up incorrectly, they’d wired it into the live wires on the kill switch so it was constantly drawing power. I can’t take credit for the full diagnosis had to employ the help of a mate who’s a fellow Mille owner and good with electrics. For peace of mind I replaced the battery with a yuasa and it’s been stood two days now and starts up on the button (I replaced the battery before finding the problem and the same happened to the Yuasa so I know it wasn’t the battery)

Thanks for taking the time reply and for the good info which no doubt will come in handy in the future, if I don’t go back to Japanese!
 

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