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Voltage drain when not running or turned on


John Ranalletta

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John Ranalletta

Just replaced the battery in the '15 GSW. Topped off the battery before install with battery tender. Installed and saw voltage drop after a few hours during which the bike ignition was turned on/off once but not started. Topped off again and measuring a few hours later saw a voltage drop with no on/off/start.

 

Yesterday, while working near the GS, I heard a faint "clicking" - almost like a soft relay click. The remote was not near the bike and the tender not plugged in.

 

In case you wonder, the only accessory onboard is the Can Opener. I have a fuse block for heated clothing but it is not connected to the battery. Only other non-stock connected to the battery is charging pigtail. Same issues reported from ADVRIDER & BMWMOA members.

 

Any guesses?

 

TIA

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Just replaced the battery in the '15 GSW. Topped off the battery before install with battery tender. Installed and saw voltage drop after a few hours during which the bike ignition was turned on/off once but not started. Topped off again and measuring a few hours later saw a voltage drop with no on/off/start.

 

Yesterday, while working near the GS, I heard a faint "clicking" - almost like a soft relay click. The remote was not near the bike and the tender not plugged in.

 

In case you wonder, the only accessory onboard is the Can Opener. I have a fuse block for heated clothing but it is not connected to the battery. Only other non-stock connected to the battery is charging pigtail. Same issues reported from ADVRIDER & BMWMOA members.

 

Any guesses?

 

TIA

 

Morning John

 

I can't help you with the clicking sound unless you can isolate it to a very specific place on the bike.

 

Now on the battery voltage drop, that is normal after a charging as the charger places a higher-than-static-charge on the battery so it will show higher than nominal

static voltage for at least 12 hours & sometimes up to 24 hours. After 12-24 hours it should stabilize & remain pretty constant at least for a day or two.

 

The only way to know for sure is to disconnect the battery from the bike, then FULLY charge, then allow to sit for 24 hours, THEN measure the static voltage (should probably be in the 12.7-12.9 volt range.

 

Then reconnect the battery to the bike & repeat the above.

 

Then see if the after 24 hour static voltage is about the same.

 

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Does not seem to be the case as you use a pigtail for your battery maintainer. My maintainer is a CAN bus compatible unit that I run through the accessory socket and as it goes from full charge stand-by mode back to top off mode I have heard a soft click from the bike sometimes. I assumed that was the bike activating the accessory circuit based on some type of signal from the maintainer.

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John Ranalletta

Bench tested the new battery. Off the tender: 13.13v. 6 hours later: 13.12v. 8 hours: 13.12v

 

On bike: Off the tender: 13.35v. 6 hours later: 13.10v. 13 hours later: 13.08v

 

So, voltage drop is not as precipitous as first thought. Will check each day for next few days.

 

Thanks.

Edited by John Ranalletta
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  • 2 weeks later...
Yeeha! Stephen

 

There have been some problems with various control modules in the wetheads causing drained batteries. Some were leaving the power on to the BMW gps Nav mount even though the gps is visually off. (a friends GS had this one)

My 16 R1200RS had a bad light control module that left the lights off, but some computer function running all the time and drained the battery overnight.

Some can be fixed with a computer re-flash/upgrade. That worked on mine for while but eventually the control module had to be replaced.

 

I'm not a tech so my explanations may be a little vague. Sorry.

 

I can't find it again, but ADV Rider has a long thread concerning this.

 

 

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roger 04 rt
Bench tested the new battery. Off the tender: 13.13v. 6 hours later: 13.12v. 8 hours: 13.12v

 

On bike: Off the tender: 13.35v. 6 hours later: 13.10v. 13 hours later: 13.08v

 

So, voltage drop is not as precipitous as first thought. Will check each day for next few days.

 

Thanks.

 

Your bike should have an AGM battery, which it came with. As DR mentioned, the battery charges at a higher voltage. About 12.84 volts is 100% charged so any declines from the charging voltage (usually around 13.8 (trickle) or 14.6 (recharge)) aren't meaningful.

 

The best way to see if you have a drain is to connect a milliammeter and measure the current after a minute or two. It should be under 4 mA.

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Bench tested the new battery. Off the tender: 13.13v. 6 hours later: 13.12v. 8 hours: 13.12v

 

On bike: Off the tender: 13.35v. 6 hours later: 13.10v. 13 hours later: 13.08v

 

So, voltage drop is not as precipitous as first thought. Will check each day for next few days.

 

Thanks.

 

Your bike should have an AGM battery, which it came with. As DR mentioned, the battery charges at a higher voltage. About 12.84 volts is 100% charged so any declines from the charging voltage (usually around 13.8 (trickle) or 14.6 (recharge)) aren't meaningful.

 

The best way to see if you have a drain is to connect a milliammeter and measure the current after a minute or two. It should be under 4 mA.

 

Morning Roger

 

Yes, that is a good (great) way to test for a parasitic drain but on vehicles with electronics it is not always as straight forward as it would seem to be.

 

We fight with this a LOT in the auto industry with trying to find parasitic draws & sneak circuits on electronics equipped vehicles.

 

For a milliamp meter to work the battery cable (or circuit power source) needs to be disconnected then the meter leads inserted between load & battery (or power source), problem is, in a lot of cases, that cuts the power to the module or electronics so the problematic module, or electronics, THEN shuts down & doesn't re-energize into it's previous power-draining condition with just the meter acting as the connection. Or, in some cases, the vehicle needs to be started, driven & used to get the errant module to go back into it's parasitic drain condition.

 

What we have been doing (for a long time now on electronics equipped vehicles ) is to hook the meter leads across the battery-post-to-cable, or across load power source BEFORE disconnecting the battery cable (or circuit power source) as that prevents the errant module or faulty electronics from powering down during the time the cable is disconnected & the meter hooked up. (this has proven to be about he only way to catch some electronic modules in the act of draining power).

 

Now the hard part, figuring out HOW to keep the meter leads fully connected across a battery post to battery cable during the disconnect. If possible, & if the problem is easily repeatable, we use a special high amp disconnect between the battery cable & battery post (installed in advance then vehicle driven & put back into whatever condition it takes to get it into the parasitic drain condition).

 

On difficult (one of a kind) parasitic drain troubleshooting I have even gone so far as to hook a second battery in parallel with the vehicle battery (hooked to the battery cables on the vehicle side of the cable connections (this keeps the vehicle side fully powered up as the vehicle battery is disconnected) then the meter is connected between the removed cable end & vehicle battery post, THEN the parallel battery is disconnected.

 

With a motorcycle battery & it's design using normal cable connections it might not be that difficult to connect the meter from cable to battery post before cable removal & have it remain connected the entire time.

 

Just something else to think about when diagnosing patristic drain conditions on electronics equipped vehicles.

 

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roger 04 rt

Good Morning DR,

 

I noticed the bike going through a restart sequence when I measured the parasitic draw on my 2017 R1200RT: http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=1003293. As you mentioned, just a momentary disconnect of the battery sent the bike through a higher current restart cycle. (On my car that restart was amps and real difficult to manage. Even opening the car door for the hood latch was a problem.)

 

On my particular bike the upset drain was about 50 mA and then after a minute it was only about 1 mA which I thought was great.

 

RB

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